Sinonasal Tract/Nasopharynx



Sinonasal Tract/Nasopharynx







8.1 ADENOID CYSTIC CARCINOMA VS. HPV-RELATED CARCINOMA WITH ADENOID CYSTIC-LIKE FEATURES

Adenoid Cystic Carcinoma

HPV-Related Carcinoma with Adenoid Cystic-Like Features


Age

Typically adults, peak incidence in sixth decade

Adults, mean 55 years


Location

Major salivary glands or minor salivary glands

Sinonasal tract


Symptoms

Slowly growing swelling, sometimes pain or paralysis due to perineural invasion. Other site-specific symptoms in minor salivary locations (e.g., nasal obstruction or epistaxis for sinonasal tumors)

Nasal obstruction and/or epistaxis


Signs

Mass in the nasal cavity and/or paranasal sinuses

Mass in the nasal cavity and/or paranasal sinuses


Etiology

Unknown. No clear relationship to tobacco or alcohol consumption

Association with high-risk types of human papillomavirus


Histology


  1. Variable mixture of tubules, cribriform structures, and solid nests (Figs. 8.1.1 and 8.1.2). Cribriform pattern is most common



  2. Two cell types: ductal and myoepithelial. The myoepithelial cells predominate; they are monotonous and basaloid and have hyperchromatic, angulated nuclei and small amounts of clear to eosinophilic cytoplasm (Fig. 8.1.3)



  3. True ducts are often subtle and are composed of cuboidal cells with eosinophilic cytoplasm (Fig. 8.1.3)



  4. Cribriform nests have cylindromatous microcystic spaces (false ducts) filled with basophilic mucoid or hyaline basement membrane-like material (Fig. 8.1.4)



  5. Tumor stroma is often hyalinized and paucicellular. It may be prominent, surrounding tumor nests and compressing them into cords (Fig. 8.1.5)



  6. Highly infiltrative. Perineural invasion is common (Fig. 8.1.6)



  7. Necrosis and elevated mitotic rates may be seen in tumors with a predominant solid pattern


  1. Predominantly solid nests of basaloid tumor cells (Fig. 8.1.9)



  2. High mitotic rate often with tumor necrosis



  3. Inconspicuous ductal formations are present within some of the nests (Fig. 8.1.10)



  4. In about half of cases, a minor component of cribriform growth (Fig. 8.1.11)



  5. In some cases, squamous dysplasia is focally present within the surface epithelium (Fig. 8.1.12)



  6. Perineural invasion may be present but is not common


Special studies


  • Immunostains for actin, calponin, S100, p63 and p40 highlight the myoepithelial cells; and immunostains for c-kit and EMA highlight the ductal cells (Figs. 8.1.7 and 8.1.8)



  • May be positive for p16 by immunohistochemistry, but HPV negative by molecular techniques



  • Approximately 50% harbor a (6;9) chromosomal translocation resulting MYB-NFIB gene fusion


  • Like with adenoid cystic carcinoma, immunostains selectively highlight the myoepithelial cells and ductal cells (Figs. 8.1.13 and 8.1.14)



  • P16 positive by immunohistochemistry; and high-risk HPV positive by molecular techniques (Fig. 8.1.15)



  • Do not harbor the t(6;9) translocation


Treatment

Wide local resection with adjuvant radiotherapy. Chemotherapeutic agents are generally ineffective

These tumors have been treated with wide resection, and a subset have received adjuvant chemotherapy and/or radiation therapy


Prognosis

Patients have a good 5-year survival (75%-80%) but poor 15-year survival (25%-30%) due to slow but relentless growth. Tumors metastasize to the lung, bone, liver, and brain. Tumors with a predominantly solid pattern are more aggressive

Clinical behavior is largely unknown due to limited patient follow-up







Figure 8.1.1 This adenoid cystic carcinoma is growing as cribriform structures and tubules.






Figure 8.1.2 This adenoid cystic carcinoma is composed of solid nests and cribriform structures.






Figure 8.1.3 The predominant cell type of adenoid cystic carcinoma is the myoepithelial cell, which has hyperchromatic, angulated nuclei and minimal, clear cytoplasm. The ductal cells (arrow) are more cuboidal with eosinophilic cytoplasm.






Figure 8.1.4 The cylindromatous spaces of the cribriform pattern are often filled with basophilic mucoid material.







Figure 8.1.5 The stroma of adenoid cystic carcinoma may be myxoid or hyalinizing, sometimes compressing the tumor nests into thin cords and tubules.






Figure 8.1.6 Adenoid cystic carcinoma is very infiltrative. Perineural and intraneural invasions are common.






Figure 8.1.7 Immunostaining for p63 highlights the myoepithelial cells of adenoid cystic carcinoma.






Figure 8.1.8 Immunostaining for c-kit highlights the ductal cells in adenoid cystic carcinoma.






Figure 8.1.9 HPV-related carcinoma with adenoid cystic-like features has a predominantly solid growth pattern.






Figure 8.1.10 The predominant cell type of HPV-related carcinoma with adenoid cystic-like features is the basaloid myoepithelial cell. At high power, ductal cells are also identified (arrows).







Figure 8.1.11 Some HPV-related carcinomas with adenoid cystic-like features exhibit cribriform structures identical to classic adenoid cystic carcinoma.






Figure 8.1.12 Some HPV-related carcinomas with adenoid cystic-like features exhibit areas of squamous dysplasia of the surface epithelium.






Figure 8.1.13 The immunophenotype of HPV-related carcinoma with adenoid cystic-like features is essentially identical to adenoid cystic carcinoma, with myoepithelial cells staining for p63.






Figure 8.1.14 Like adenoid cystic carcinoma, c-kit highlights the ductal structures of HPV-related carcinoma with adenoid cystic-like features.






Figure 8.1.15 HPV-related carcinomas with adenoid cystic-like features are positive for high-risk HPV (usually type 33) by in situ hybridization.



8.2 ALLERGIC FUNGAL SINUSITIS VS. MYCETOMA

Allergic Fungal Sinusitis

Mycetoma


Age

Typically young adults

Typically young adults


Location

Paranasal sinuses

Paranasal sinuses, especially maxillary sinus


Symptoms

Nasal discharge, allergic symptoms

Nasal discharge and allergic symptoms, similar to allergic sinusitis


Signs

Peripheral eosinophilia, elevated serum IgE levels. Sinus contents contain firm, tenacious, foul-smelling mucus

Sinus opacification, sometimes with calcifications on imaging


Etiology

Allergic reaction to fungal antigens (most commonly Aspergillus species)

Colonization of the sinuses by fungal organisms (most frequently Aspergillus species)


Histology


  1. “Allergic mucin” with a striated (“tigroid”) appearance due to laminated deposition of eosinophils, neutrophils, Charcot-Leyden crystals, fibrin, and mucin (Figs. 8.2.1 and 8.2.2)



  2. There is no invasion of tissue by fungal elements



  3. Background sinonasal mucosa with edema, chronic inflammation, and abundant eosinophils


  1. Matted collection of distorted fungal hyphae, sometimes calcified (Figs. 8.2.4 and 8.2.5)



  2. There is no invasion of tissue by fungal elements



  3. Fruiting bodies (conidia) may be evident (Fig. 8.2.6)



  4. Mycetomas caused by Aspergillus niger may exhibit pigmentation and calcium oxalate crystals (Fig. 8.2.6)


Special studies

GMS or PAS may reveal scattered degenerating fungal hyphae within the allergic mucin in about one-half of cases (Fig. 8.2.3)

Fungal hyphae easily identified without the need for special stains


Treatment

Removal of the tenacious mucus to restore mucociliary function, and intranasal steroids. Fungal desensitization may play a role in therapy. There is no role for antifungal agents

Removal of the mass. No additional therapy indicated


Prognosis

Long-term therapy (e.g., intranasal steroids) may be needed to control relapses

Excellent once the mass is removed








Figure 8.2.1 The characteristic feature of allergic fungal sinusitis is allergic mucin. It has a striated (“tigroid”) appearance due to the layering of cellular debris.






Figure 8.2.2 Allergic mucin is composed of degranulating eosinophils, degenerating neutrophils, and Charcot-Leyden crystals in a background of fibrin and mucin.






Figure 8.2.3 Fungal elements can sometimes be identified when special stains like GMS are performed. The fungal hyphae are typically degenerated, fragmented, and scattered within the allergic mucin.






Figure 8.2.4 Mycetoma is sometimes referred to as a “fungus ball” because it is a mass of fungal hyphae growing within the paranasal sinus. It does not invade the tissues.






Figure 8.2.5 At high power, mycetoma is composed of matted hyaline fungal hyphae.






Figure 8.2.6 On occasion, fungal fruiting bodies (conidia) can be identified. In this case of Aspergillus niger mycetoma, the spores coming off of the fruiting body are pigmented.



8.3 SINONASAL AMELOBLASTOMA VS. NONKERATINIZING SQUAMOUS CELL CARCINOMA

Sinonasal Ameloblastoma

Nonkeratinizing Squamous Cell Carcinoma


Age

Adults, mean age approximately 60 years, with a male predominance

Adults in their sixth to seventh decades, with a male predominance


Location

Maxillary sinus or nasal cavity

Maxillary sinus is most common, followed by nasal cavity and ethmoid sinus. Primary carcinomas of the frontal and sphenoid sinuses are very rare


Symptoms

Nasal obstruction

Nasal obstruction, epistaxis, facial pain and/or fullness, rhinorrhea, and eye-related symptoms like diplopia or proptosis in advanced cases


Signs

Nasal mass

Nasal mass or ulcer


Etiology

May arise from ectopic odontogenic rests or sinonasal surface epithelial basal cells

Weak link to cigarette smoking and industrial chemical agents. Some may be related to HPV


Histology


  1. Nests, sheets, and thickened cords of squamoid cells (Fig. 8.3.1)



  2. The peripheral cells are columnar and demonstrate palisading and reverse polarization away from the basement membrane (Figs. 8.3.2 and 8.3.3)



  3. The central intercellular zones are loose and edematous, similar to stellate reticulum of a developing tooth (Fig. 8.3.3)



  4. The tumor-stromal interface is often hyalinized



  5. Histologic variants include follicular, plexiform, basaloid, granular cell, and acanthomatous (squamous)



  6. Minimal cellular atypia, no necrosis, and minimal mitotic figures (Figs. 8.3.2 and 8.3.3)


  1. Expanding nests and anastomosing ribbons of cells with a smooth stromal interface and limited desmoplasia (Fig. 8.3.4)



  2. Nests often show peripheral palisading of elongated cells, but no reverse polarization or central stellate reticulum (Fig. 8.3.5)



  3. Keratinization is limited or absent



  4. Papillary architecture may be seen in the invasive tumor or surface tumor component



  5. Cellular atypia is present, mitotic activity is high, and necrosis is common (Fig. 8.3.5)


Special studies

Has a squamous immunophenotype: diffusely positive for p63, p40, and CK5/6. Negative for human papillomavirus

Diffusely positive for p63, p40, and CK5/6. Some cases are positive for high-risk human papillomavirus


Treatment

Surgery

Multimodality (surgery and radiation, and sometimes chemotherapy)


Prognosis

May recur if incompletely excised

5-year survival approximately 60%








Figure 8.3.1 Sinonasal ameloblastoma consisting of nests and trabeculae of cells in the sinonasal submucosa.






Figure 8.3.2 Sinonasal ameloblastoma with a plexiform growth pattern.






Figure 8.3.3 Sinonasal ameloblastoma demonstrating characteristic peripheral columnar cells with palisading and reverse polarization away from the periphery. The central cells are more loosely arranged. There is no significant atypia, mitotic activity, or necrosis.






Figure 8.3.4 Sinonasal nonkeratinizing squamous cell carcinoma with large anastomosing ribbons of cells.






Figure 8.3.5 Sinonasal nonkeratinizing squamous cell carcinoma with atypical squamoid cells and scattered mitotic figures.



8.4 ANGIOFIBROMA VS. ANTROCHOANAL SINONASAL POLYP

Angiofibroma

Antrochoanal Sinonasal Polyp


Age

Almost exclusively young males (10-25 years)

Usually males, teenagers, or young adults


Location

Arise in the nasopharynx with secondary extension into the sinonasal tract

Arise from the antrum of the maxillary sinus and extend through the ostium via a pedicle into the nasal cavity


Symptoms

Recurrent epistaxis and/or obstruction

Obstruction, allergic symptoms


Signs

Classically, a mass protruding into the nasal cavity that bleeds easily on palpation. Radiologically appears as a mass with bowing of the posterior wall of the maxillary sinus (Holman-Miller sign)

Unilateral polypoid mass


Etiology

Tumor growth is androgen driven and occurs around puberty. Some cases have arisen in the setting of familial adenomatoid polyposis and harbored activating mutations in the APC gene

Likely allergic, similar to typical inflammatory sinonasal polyps


Histology


  1. At low power, dilated, thin-walled vessels with a slitlike or “staghorn” appearance (Fig. 8.4.1)



  2. The vessels are surrounded by a fibrotic stroma of variable cellularity (Fig. 8.4.2)



  3. Except for scattered mast cells, inflammation is minimal or absent (except when embolized)



  4. The stroma cells have bland ovoid, spindled, or stellate nuclei with indistinct nucleoli (Fig. 8.4.3)



  5. Because angiofibromas are often embolized preoperatively, necrosis and intravascular embolization material may be seen


  1. Polypoid tissue fragments with abundant stroma fibrosis and edema (Fig. 8.4.5)



  2. Scattered chronic inflammatory cells (lymphocytes and plasma cells). Eosinophils may be present, but they are usually not abundant (Fig. 8.4.6)



  3. Blood vessels are small, inconspicuous, and not dilated



  4. The stroma is often more edematous and less collagenized than angiofibromas


Special studies

The stromal tumor cells are positive for beta-catenin (nuclear), diffusely positive for androgen receptor, and variably positive for actin (Fig. 8.4.4)

Negative for beta-catenin and androgen receptor


Treatment

Surgery. Preoperative embolization of the feeding vessel is commonly employed to reduce operative bleeding

Simple excision, along with medical treatment of underlying allergic sinusitis


Prognosis

Benign but can be locally aggressive and recur

Benign, but may recur, particularly if the stalk is not removed








Figure 8.4.1 Angiofibromas are composed of a proliferation of vessels in a fibrotic stroma.






Figure 8.4.2 Angiofibroma with dilated, thin-walled, branching vessels and an associated fibroblastic stroma.






Figure 8.4.3 The stromal cells of angiofibroma have bland, oval to stellate nuclei and are separated by collagen. The muscular layer of the blood vessels is often absent or poorly formed.






Figure 8.4.4 The stroma cells of angiofibroma demonstrate nuclear expression of beta-catenin.






Figure 8.4.5 Antrochoanal polyp with abundant stromal fibrosis and edema. Vessels are inconspicuous.






Figure 8.4.6 Antrochoanal polyp with a mild infiltrate of chronic inflammatory cells.



8.5 ANGIOFIBROMA VS. SOLITARY FIBROUS TUMOR

Angiofibroma

Solitary Fibrous Tumor


Age

Almost exclusively males, children, or young adults (10-25 years)

Typically adults


Location

Arise in the nasopharynx with secondary extension into the sinonasal tract

Various head and neck sites including nasal cavity and paranasal sinuses


Symptoms

Recurrent epistaxis and/or obstruction

Nonspecific symptoms including nasal obstruction, epistaxis, and congestion


Signs

Classically, a mass protruding into the nasal cavity that bleeds easily on palpation. Radiologically appears as a mass with bowing of the posterior wall of the maxillary sinus (Holman-Miller sign)

Nasal mass/polyp. May cause bone erosion with distortion of surrounding structures


Etiology

Tumor growth is androgen driven and occurs around puberty. Some cases have arisen in the setting of familial adenomatoid polyposis and harbored activating mutations in the APC gene

Unknown


Histology


  1. Dilated vessels with absent or attenuated smooth muscle wall and a slitlike or branching (“staghorn”) appearance (Figs. 8.5.1 and 8.5.2)



  2. Unencapsulated, with fibrotic stroma of low to moderate cellularity (Fig. 8.5.2)



  3. The stroma cells have bland ovoid, spindled, or stellate nuclei with indistinct nucleoli (Fig. 8.5.3)



  4. Because angiofibromas are often embolized preoperatively, necrosis and intravascular embolization material may be seen


  1. Thin-walled, dilated vessels with no smooth muscle and a slitlike or branching (“staghorn”) appearance (Fig. 8.5.5)



  2. Unencapsulated, spindle cell proliferation growing in a haphazard (“patternless”) pattern (Fig. 8.5.6)



  3. Cells separated by variable amounts of collagen (Fig. 8.5.7)



  4. Cells have uniform spindled nuclei and generally lack significant atypia or mitotic activity


Special studies

The stromal tumor cells are positive for beta-catenin (in a nuclear distribution) and androgen receptor; and they are negative for CD34 and STAT6 (Fig. 8.5.4)

Positive for CD34 and STAT6 (nuclear) (Fig. 8.5.8). Negative for nuclear beta-catenin and androgen receptor NAB2-STAT6 translocation appears to be specific for this tumor


Treatment

Surgery. Preoperative embolization of the feeding vessel is commonly employed to reduce operative bleeding

Complete surgical excision


Prognosis

Benign but can be locally aggressive and recur

Indolent tumor. Local recurrence uncommon following complete removal. Malignant solitary fibrous tumors of the sinonasal tract have been reported but are rare








Figure 8.5.1 Angiofibroma with a moderately cellular proliferation of spindle cells associated with dilated blood vessels.






Figure 8.5.2 Angiofibroma with dilated vessels containing an attenuated smooth muscle wall.






Figure 8.5.3 Angiofibroma with bland, angulated tumor cells.






Figure 8.5.4 Angiofibroma is consistently positive for beta-catenin in a nuclear distribution.






Figure 8.5.5 Solitary fibrous tumor with branching, staghorn vessels that lack a smooth muscle layer.






Figure 8.5.6 Solitary fibrous tumor grows in a haphazard (“patternless”) arrangement, with alternating zones of hyper- and hypocellularity.







Figure 8.5.7 Solitary fibrous tumor with uniform spindled tumor cells and dense bundles of intervening collagen.






Figure 8.5.8 Solitary fibrous tumor with nuclear immunoreactivity for STAT6.



8.6 BIPHENOTYPIC SINONASAL SARCOMA VS. SINONASAL SCHWANOMA

Biphenotypic Sinonasal Sarcoma

Sinonasal Schwannoma


Age

Typically middle age (mean 52) women (male to female ratio of 1:3)

Wide age range, but typically adults (male to female ratio 1:1)


Location

Typically superior aspects of the nasal cavity and ethmoid sinuses

No specific site predilection within the sinonasal tract


Symptoms

Nonspecific symptoms such as nasal congestion and facial pressure

Obstruction, epistaxis, and visual disturbances


Signs

Destructive heterogeneously enhancing mass by imaging

May have an alarming radiologic appearance with bone erosion and involvement of local structures


Etiology

Unknown

Unknown. Usually sporadic and unrelated to neurofibromatosis


Histology


  1. Poorly circumscribed and unencapsulated, with frequent invasion of bone



  2. Gaping branching (“staghorn”) vessels (Fig. 8.6.1)



  3. Uniformly hypercellular



  4. The tumor entraps submucosal gland (Fig. 8.6.2)



  5. “Herringbone” fascicular growth pattern



  6. Elongated nuclei without significant atypia. Mitotic activity is low (Fig. 8.6.3)


  1. Often poorly circumscribed and unencapsulated (unlike schwannomas of other sites) (Fig. 8.6.6)



  2. Nuclear palisading (Verocay bodies). Mixed hypercellular (Antoni A) and hypocellular (Antoni B) zones, but mostly hypercellular (Fig. 8.6.7)



  3. Dilated branching vessels and entrapment of submucosal glands are not seen



  4. Hyalinized vessels are common (Fig. 8.6.8)



  5. Degenerative nuclear atypia in the form of bizarre, hyperchromatic nuclei with “smudgy” chromatin may be seen



  6. Mitotic figures can be seen (but no atypical mitoses)


Special studies


  • S100 focally positive (Fig. 8.6.4)



  • Actin focally positive (Fig. 8.6.5)



  • Cytokeratin, EMA, desmin, and myogenin occasionally positive focally



  • Beta-catenin usually positive (nuclear) and SOX10 negative



  • The PAX3-MAML3 fusion is diagnostic


  • S100 diffusely positive (Fig. 8.6.9)



  • Actin, desmin, cytokeratin, and EMA generally negative



  • SOX10 diffusely positive and beta-catenin negative (Fig. 8.6.10)



  • PAX3 rearrangements are absent


Treatment

Typically resection only

Resection


Prognosis

Almost half of patients experience local recurrences, but metastatic spread has not been reported, and only rare tumor-related deaths

Excellent








Figure 8.6.1 Biphenotypic sinonasal sarcoma frequently exhibits dilated branching vessels.






Figure 8.6.2 Biphenotypic sinonasal sarcoma entraps submucosal ducts and glands.






Figure 8.6.3 Biphenotypic sinonasal sarcoma grows as a uniformly hypercellular proliferation of spindled cells with elongated nuclei in a “herringbone” fascicular pattern. Mitotic activity, significant nuclear atypia, and necrosis are absent.






Figure 8.6.4 Biphenotypic sinonasal sarcoma is almost always S100 positive, but staining is usually focal.






Figure 8.6.5 Biphenotypic sinonasal sarcoma is usually positive for actin in a focal distribution.






Figure 8.6.6 Sinonasal schwannoma is typically unencapsulated.







Figure 8.6.7 Palisading tumor nuclei (Verocay bodies), while classic for schwannoma, are not always seen in schwannomas of the sinonasal tract.






Figure 8.6.8 Sinonasal schwannoma with hyalinized vessels.






Figure 8.6.9 Schwannoma is diffusely and strongly positive for S100.






Figure 8.6.10 Schwannoma is also characteristically positive for SOX10, in contrast to biphenotypic sinonasal sarcoma.



8.7 CAVERNOUS HEMANGIOMA VS. NORMAL TURBINATE HISTOLOGY

Cavernous Hemangioma

Normal Turbinate Histology


Age

All ages, but peak incidence in fourth and fifth decades

Not applicable


Location

Most frequently turbinates, lateral nasal wall, or nasal bones (intraosseous hemangioma) (in contrast to lobular capillary hemangioma, which most frequently involves the septum)

Turbinates


Symptoms

Epistaxis and obstruction

Not applicable


Signs

Nasal mass or polyp, soft and spongy, may be red or purple in color

Not applicable


Etiology

Unknown

Not applicable


Histology


  1. Variably sized, dilated vessels lined by endothelial cells (Fig. 8.7.1)



  2. Vessels are irregularly shaped and haphazardly spaced, with little intervening stroma (Figs. 8.7.1 and 8.7.2)



  3. Vessels have thin walls that lack a smooth muscle layer (Figs. 8.7.1, 8.7.2 and 8.7.3)



  4. Intraluminal thrombi may be seen (Fig. 8.7.3)


  1. The turbinates of the nasal cavity normally possess erectile tissue that may be mistaken for a hemangioma (Figs. 8.7.4 and 8.7.5)



  2. The erectile tissue consists of a network of vessels that are large and evenly spaced with intervening stromal tissue (Figs. 8.7.4 and 8.7.5)



  3. The vessels have a thick layer of smooth muscles (Figs. 8.7.4 and 8.7.5)



  4. No intraluminal thrombi


Special studies

None useful in this differential diagnosis

None useful in this differential diagnosis


Treatment

Surgical excision

Not applicable


Prognosis

Excellent

Not applicable








Figure 8.7.1 Cavernous hemangioma with numerous dilated, irregularly shaped vessels with a haphazard arrangement.






Figure 8.7.2 Cavernous hemangioma is composed of irregularly shaped, thin-walled vessels without a smooth muscle layer.






Figure 8.7.3 Cavernous hemangioma with an organized intraluminal thrombus.






Figure 8.7.4 Normal turbinate with a submucosal network of large, evenly spaced, thick-walled vessels.






Figure 8.7.5 The normal turbinate contains erectile tissue composed of evenly spaced vessels with a well-developed layer of smooth muscle.



8.8 CHEMOTHERAPY-INDUCED EPITHELIAL ATYPIA VS. SQUAMOUS DYSPLASIA

Chemotherapy-induced Epithelial Atypia

Squamous Dysplasia


Age

Any age or sex may be affected

Usually sixth or seventh decades


Location

Anywhere along the sinonasal tract. Similar changes have been reported in other sites including the lung, bladder, and breast

In most cases, it is present in association with an invasive squamous cell carcinoma, which arises most often in the nasal cavity or maxillary sinus


Symptoms

None by itself. Biopsy prompted by the suspicion of invasive fungal sinusitis in patients who have received chemotherapy for a hematologic malignancy

None by itself. In most cases, squamous dysplasia is present in association with an invasive squamous cell carcinoma


Signs

None by itself

None by itself


Etiology

Induced by alkylating chemotherapeutic agents (e.g., cyclophosphamide or melphalan)

Unknown in most cases. There is a modest association with cigarette smoking. Some cases may be HPV related


Histology


  1. Marked nuclear atypia in the form of bizarre, enlarged hyperchromatic nuclei with irregular contours and prominent nucleoli (Figs. 8.8.1 and 8.8.2)



  2. No accompanying basal cell hyperplasia. In some cases, basal layer is spared (Figs. 8.8.1 and 8.8.2)



  3. Atypical nuclei may be singly dispersed or clustered or involve the full thickness of the epithelium (Fig. 8.8.2)



  4. Mitotic figures rare or absent (Figs. 8.8.1 and 8.8.2)



  5. Atypical nuclei have a degenerative, “smudgy” chromatin quality and low nuclear-to-cytoplasmic ratios (Fig. 8.8.2)


  1. Nuclei atypia in the form of hyperchromatic nuclei, nuclear pleomorphism, and prominent nucleoli (Fig. 8.8.3)



  2. Tends to involve the basal layer with atypia extending higher into the epithelium with increasing severity



  3. Basal cell layer hyperplasia and crowding usually present (Fig. 8.8.3)



  4. Mitotic figures above the basal cell layer usually found along with dyskeratotic cells (Fig. 8.8.3)



  5. Atypical nuclei have high nuclear to cytoplasmic ratios (Fig. 8.8.3)


Special studies

Ki-67 index is low. Negative for various viruses (cytomegalovirus, herpes simplex virus, adenovirus) by immunohistochemistry

Ki-67 index is high


Treatment

No specific treatment required

Most dysplasias are seen in association with invasive squamous cell carcinoma, which is treated with surgery and/or chemoradiation


Prognosis

Dependent on underlying disease process

Dependent on the stage of the invasive squamous cell carcinoma








Figure 8.8.1 Chemotherapy-induced atypia involving the sinonasal tract. There are randomly distributed cells with enlarged and hyperchromatic nuclei.






Figure 8.8.2 Chemotherapy-induced atypia involving the sinonasal tract. The atypical cells have abundant and sometimes vacuolated cytoplasm, multinucleation, and a degenerated appearance that resembles viral cytopathic effect. Mitotic figures are not present.






Figure 8.8.3 Sinonasal squamous dysplasia. There is abnormal maturation, nuclear enlargement with high nuclear:cytoplasmic ratios, dyskeratotic cells, and increased mitotic activity.



8.9 SINONASAL ENCEPHALOCELE VS. GLIAL HETEROTOPIA

Sinonasal Encephalocele

Glial Heterotopia


Age

Congenital or acquired later in life

Usually infants, but occasionally encountered in older patients


Location

Involves the sinonasal tract with direct communication with the intracranial cavity

Either intranasal or extranasal (most often on the bridge or side of the nose)


Symptoms

Nasal obstruction, difficulty with feeding in infants

Nasal obstruction, difficulty with feeding in infants


Signs

Firm nodule in the nasal cavity or overlying skin. Radiology reveals a connection to the intracranial cavity

Firm nodule in the nasal cavity or overlying skin. No connection to the intracranial cavity by radiology


Etiology

Congenital encephaloceles are sporadic. Acquired encephaloceles are the result of trauma, sometimes a complication of surgery

Failure of the developing frontal lobe to completely retract into the cranial cavity during fetal development. The term “nasal glioma” is not preferred because the lesion is not neoplastic


Histology


  1. Brain tissue that tends to be well organized, occasionally with neurons (Fig. 8.9.1)



  2. Dura and meninges may be present



  3. Long-standing lesions may be distorted and very fibrotic, obscuring the neural tissue



  4. Hemorrhage and hemosiderin may be seen in acquired lesions



  5. In many cases, it may be histologically indistinguishable from glial heterotopia, necessitating correlation with clinical and radiographic findings


  1. No dura or meninges



  2. Glial tissue without organization or neurons (Fig. 8.9.2)



  3. Fibrosis may obscure the presence of glial tissue



  4. In many cases, it may be histologically indistinguishable from encephalocele, necessitating correlation with clinical and radiographic findings


Special studies

GFAP and S100 highlight the glial tissue. Synaptophysin highlights neurons

GFAP and S100 highlight the glial tissue


Treatment

Surgery

Surgery


Prognosis

Excellent for acquired, variable for congenital. Some children experience developmental delay

Excellent








Figure 8.9.1 Encephalocele with lobules of well-organized, normal-appearing glial cells and neurons.






Figure 8.9.2 Glial heterotopia with fibrillar glial tissue in the sinonasal submucosa, entrapping native glands.



8.10 ACUTE/FULMINANT INVASIVE FUNGAL SINUSITIS VS. CHRONIC/INDOLENT INVASIVE FUNGAL SINUSITIS

Acute/Fulminant Invasive Fungal Sinusitis

Chronic/Indolent Invasive Fungal Sinusitis


Age

Any age or sex affected

Any age or sex


Location

Paranasal sinuses

Paranasal sinuses


Symptoms

Rapid onset of nasal discharge and pain

Chronic headache and facial swelling that may progress over months to years


Signs

Facial swelling and sinus destruction with possible brain invasion on imaging

Enlarging mass in the face and/or orbit, sometimes with proptosis


Etiology

Fungal infection in severely immunodeficient patient (usually neutropenic)

Fungal infection in partially immunodeficient patient (e.g., diabetes mellitus, chronic steroid therapy)


Fungal organisms

Hyalohyphomycetes (e.g., Aspergillus sp., Fusarium sp.) or zygomycetes (e.g., Rhizopus sp., Mucor sp.)

Usually hyalohyphomycetes (especially Aspergillus fumigatus)


Histology


  1. Fungal hyphae within necrotic tissue. Neutrophils are notably absent (Fig. 8.10.1)



  2. Numerous fungal hyphae within tissues, including vessels (angioinvasion) (Fig. 8.10.2)



  3. Frequent necrosis due to fungal angioinvasion


  1. Invasive fungi induce a granulomatous and chronic inflammatory reaction (Figs. 8.10.4 and 8.10.5)



  2. Fungal organisms identified but often not numerous



  3. Necrosis and angioinvasion not seen


Special studies

GMS or PAS stains may highlight the fungal organisms. Zygomycetes have wide, ribbon-like hyphae with right angle branching and few septa; hyalohyphomycetes possess thin hyphae with numerous septa and acute angle branching (Figs. 8.10.3 and 8.10.4)

GMS or PAS stains highlight the fungal organisms (Fig. 8.10.6). Hyalohyphomycetes possess thin hyphae with numerous septa and acute angle branching


Treatment

Prompt surgical intervention with systemic antifungal agents

Debridement, sometimes with systemic antifungal agents


Prognosis

Often fatal

Good, though recurrences not uncommon








Figure 8.10.1 Acute/fulminant invasive fungal sinusitis with necrosis and minimal inflammatory reaction.






Figure 8.10.2 Acute/fulminant invasive fungal sinusitis with angioinvasion by fungal hyphae.






Figure 8.10.3 Acute/fulminant invasive fungal sinusitis caused by Rhizopus sp. consisting of large, twisting, ribbon-like hyphae with few septa.






Figure 8.10.4 Acute/fulminant invasive fungal sinusitis caused by Aspergillus sp. consisting of numerous thin, acute branching hyphae.






Figure 8.10.5 Chronic/indolent invasive fungal sinusitis with chronic and granulomatous inflammation.






Figure 8.10.6 Chronic/indolent invasive fungal sinusitis caused by Aspergillus sp. with scattered fungal hyphae highlighted by a GMS stain.



8.11 GLOMANGIOPERICYTOMA (HEMANGIOPERICYTOMA-LIKE TUMOR OF THE SINONASAL TRACT) VS. SOLITARY FIBROUS TUMOR

Glomangiopericytoma (Hemangiopericytoma-Like Tumor of the Sinonasal Tract)

Solitary Fibrous Tumor


Age

All ages, but peak incidence in sixth and seventh decades

Typically adults


Location

Usually lateral nasal cavity but may extend into paranasal sinuses

Various head and neck sites including nasal cavity and paranasal sinuses


Symptoms

Nonspecific symptoms including nasal obstruction, epistaxis, and congestion

Nonspecific symptoms including nasal obstruction, epistaxis, and congestion


Signs

Nasal mass/polyp. May cause bone erosion with distortion of surrounding structures

Nasal mass/polyp. May cause bone erosion with distortion of surrounding structures


Etiology

Unknown

Unknown


Histology


  1. Nonencapsulated, subepithelial proliferation with uniform cellularity (Fig. 8.11.1)



  2. Closely packed cells without intervening collagen growing in a solid or swirling fashion



  3. Thin-walled blood vessels that lack a muscular coat but show varying degrees of perivascular hyalinization (Fig. 8.11.2). “Staghorn” vessels may be present (Fig. 8.11.3)



  4. Cells have uniformly round to ovoid nuclei with inconspicuous nucleoli (Figs. 8.11.2 and 8.11.4)


  1. Nonencapsulated, subepithelial proliferation with alternating zones of hyper- and hypocellularity



  2. Thin-walled blood vessels, some with “staghorn” configuration (Fig. 8.11.6)



  3. Cells separated by varying degrees of intervening collagen (Figs. 8.11.7 and 8.11.8)



  4. Cells have uniform spindled nuclei without significant atypia (Figs. 8.11.7 and 8.11.8). The mitotic rate is low


Special studies

Usually positive for beta-catenin (nuclear), actin and FXIIIa (Fig. 8.11.5). Negative for CD34

Usually negative for actin, beta-catenin and FXIIIa. Positive for CD34 (Fig. 8.11.9)


Treatment

Complete surgical excision

Complete surgical excision


Prognosis

Indolent tumor. Local recurrences are not uncommon (about 30%). Aggressive behavior (i.e., malignant glomangiopericytoma) is rare

Indolent tumor. Local recurrence uncommon following complete removal. Malignant solitary fibrous tumors of the sinonasal tract have been reported but are rare








Figure 8.11.1 Glomangiopericytoma showing sheetlike proliferation of neoplastic cells with little intervening stroma.






Figure 8.11.2 The neoplastic cells of glomangiopericytoma are closely packed and interrupted by numerous thin-walled vessels that are often cuffed by a zone of collagen.






Figure 8.11.3 Same tumor as Figure 8.11.2, ectatic vessels are present in adjacent zone of sclerosis.






Figure 8.11.4 The neoplastic cells of glomangiopericytoma are round to slightly oval and have uniform nuclei and clear to eosinophilic cytoplasm.






Figure 8.11.5 The neoplastic cells of glomangiopericytoma are often actin positive.






Figure 8.11.6 A cellular zone in a solitary fibrous tumors of the nasal cavity.







Figure 8.11.7 A zone of low cellularity in a solitary fibrous tumor of the nasal cavity where bland spindled cells are dispersed in a collagenized stroma.






Figure 8.11.8 Thin-walled ectatic vessels in a solitary fibrous tumor.






Figure 8.11.9 Strong and diffuse CD34 positivity in a solitary fibrous tumor.



8.12 INFLAMMATORY SINONASAL POLYPS VS. ANTROCHOANAL SINONASAL POLYP

Inflammatory Sinonasal Polyps

Antrochoanal Sinonasal Polyp


Age

Uncommon in patients under 20 years of age

Usually males, teenagers, or young adults


Location

Nasal cavity and paranasal sinuses. Involvement of lateral nasal wall especially common. Usually bilateral

Arise from the antrum of the maxillary sinus and extend through the ostium via a pedicle to extend into the nasal cavity. Usually unilateral


Symptoms

Nasal obstruction and allergic symptoms like rhinorrhea

Nasal obstruction and allergic symptoms like rhinorrhea


Signs

Often multiple and bilateral sessile polypoid projections

Unilateral polypoid mass


Etiology

Association with allergy and asthma and aspirin sensitivity

An association with an allergic condition is less common than with inflammatory polyps


Histology


  1. Polypoid fragments of sinonasal mucosa with abundant stromal edema (Fig. 8.12.1)



  2. Chronic inflammatory cell infiltrate with numerous eosinophils (Fig. 8.12.2)



  3. The epithelial basement membrane is usually hyalinized (Fig. 8.12.2)



  4. Seromucinous gland hyperplasia may be present



  5. Secondary changes including infarction, hemorrhage, and fibrin deposition can be seen


  1. Polypoid tissue fragments with stromal edema (Fig. 8.12.3)



  2. Compared to inflammatory polyps, antrochoanal polyps have increased stromal fibrosis and fewer seromucinous glands (Fig. 8.12.3)



  3. Scattered chronic inflammatory cells but eosinophils are usually not abundant (Fig. 8.12.4)



  4. Basement membrane hyalinization absent or minimal (Fig. 8.12.4)



  5. Prone to secondary changes including infarction, hemorrhage, and fibrin deposition


Special studies

None useful in this differential diagnosis

None useful in this differential diagnosis


Treatment

Endoscopic surgery and treatment of underlying cause (e.g., nasal steroids for allergic polyps)

Simple excision, along with medical treatment of underlying allergic sinusitis


Prognosis

Excellent

May recur, particularly if the stalk is not removed








Figure 8.12.1 Inflammatory sinonasal polyp consisting of a polypoid fragment of sinonasal mucosa with underlying stromal edema, chronic inflammation, and seromucinous gland hyperplasia.






Figure 8.12.2 Inflammatory sinonasal polyp with subepithelial basement membrane hyalinization and chronic inflammation including numerous eosinophils.






Figure 8.12.3 Antrochoanal polyp consisting of a polypoid fragment of sinonasal mucosa with increased fibrosis, minimal inflammation, and an absence of seromucinous glands.






Figure 8.12.4 Antrochoanal polyps do not have well-developed basement membrane hyalinization, and the inflammatory infiltrate often lacks abundant eosinophils.



8.13 INTESTINAL-TYPE SINONASAL ADENOCARCINOMA VS. NONINTESTINAL SINONASAL ADENOCARCINOMA

Intestinal-Type Sinonasal Adenocarcinoma

Nonintestinal Sinonasal Adenocarcinoma


Age

Broad age distribution, with most cases occurring in fifth to seventh decades

Broad age distribution, with most cases occurring in fifth to seventh decades


Location

Ethmoid sinus is most commonly involved site

Low grade: usually involve the nasal cavity or ethmoid sinus


High grade: usually arise from maxillary sinus


Symptoms

Nasal obstruction, epistaxis, and congestion

Nasal obstruction, epistaxis, and congestion. High-grade adenocarcinoma may also present with eye-related symptoms or cranial nerve deficits


Signs

Variable

Variable, often exophytic mass with papillary appearance


Etiology

Strong association with wood dust, leather dust, and other occupational exposures

No known occupational or environmental factors


Histology


  1. Resembles colorectal adenoma/adenocarcinomas



  2. Variable growth patterns including papillary, tubular/glandular, mucinous, and solid (Figs. 8.13.1, 8.13.2 and 8.13.3)



  3. Cells are often columnar with pseudostratified nuclei demonstrating vesicular chromatin and prominent nucleoli (Fig. 8.13.1)



  4. Degree of atypia and mitotic activity is variable. Tumors with papillary architecture have a more bland appearance, while the solid pattern is associated with nuclear pleomorphism, high mitotic rates, and necrosis (Figs. 8.13.1 and 8.13.3)



  5. Solid forms may be difficult to even recognize as adenocarcinoma, with only focal gland formation or mucin production

Low grade:




  1. Highly variable growth patterns including papillary, acinar, and tubular



  2. Glands are back to back, fused, and lined by cuboidal to columnar cells with only mild atypia and minimal mitotic activity (Fig. 8.13.6).



  3. No nuclear pseudostratification


    High grade:



  4. Variable growth patterns including acinar, papillary, and solid



  5. Pleomorphism, high mitotic rates, and tumor necrosis (Figs. 8.13.7 and 8.13.8)



  6. Solid forms may be difficult to even recognize as adenocarcinoma, with only focal gland formation or mucin production


Special studies

CDX2 positive and CK20 positive (Figs. 8.13.4 and 8.13.5). May be positive for CK7

CK7 positive, CK20 negative, and CDX2 negative


Treatment

Surgery with or without radiation therapy

Complete surgical excision


Prognosis

Poor, with a 5-year survival of about 40%-50%. The papillary subtype appears to be more indolent

Grade dependent. Low-grade adenocarcinomas are very indolent. High-grade adenocarcinoma has a poor prognosis, with 3-year survival of about 20%

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Sep 25, 2018 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Sinonasal Tract/Nasopharynx

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