Poroma and Dermal Duct Tumor
Clinical Photograph of PoromaClinical photograph shows a traumatized poroma on the lower back of an adult male, which presented as an irritated polypoid lesion. Poroma With Squamoid FeaturesLow magnification of…
Pigmented Spindle Cell Nevus (Reed Nevus)
Typically show hyperchromatic-staining nuclei with small nucleoli Cytoplasm with prominent melanin pigmentation • Atypical Reed nevus Often larger, more cellular lesions Increased mitotic activity, especially in junctional component Top Differential Diagnoses…
Sebaceoma (Sebaceous Epithelioma)
Autosomal dominant disease due to mutations in mismatch repair genes MLH1, MSH2, MSH6 Multiple sebaceous tumors including sebaceous adenomas, less likely carcinomas and sebaceomas Clinical Issues • Rare tumors; typically occur…
Squamous Cell Carcinoma (and Variants)
Malignant epithelial tumor of squamous keratinocytes Etiology/Pathogenesis • Most cases are related to UV radiation • Previous radiation therapy implicated in some cases; usually associated with more aggressive SCC Clinical Issues • Often…
Fibromatosis
4-6% of Caucasian adults > 50 years of age • Deep fibromatosis 2.40-4.43 new cases per 100,000 persons/year • Recurrences common for both superficial and deep fibromatoses, but deaths only from deep…
Verrucous Carcinoma (and Variants)
Other locations are less frequent • Usually solitary Multicentric tumors can occur • Some cases may be associated with viral warts (plantar lesions) • Verrucous carcinoma (VC) may arise in setting of longstanding…
Epithelioid Hemangioendothelioma
Multicentricity at presentation likely represents locoregional metastases • Treatment: Wide surgical excision with negative margins • Indolent clinical course in majority of cases • Metastases in 20-30% • Overall mortality rate of 10-20% High-risk…
Trichoepithelioma
Superficial folliculocystic structures and calcifications Deeper infiltrative-appearing cords and small islands in densely fibrotic stroma Top Differential Diagnoses • Basal cell carcinoma • Microcystic adnexal carcinoma • Trichoblastoma • Trichoadenoma • Sebaceoma Clinical Photograph of…
Cylindroma
Can have areas indistinguishable from cylindroma Usually encapsulated Tumor stroma has prominent vasculature • Malignant cylindroma/cylindrocarcinoma • Basal cell carcinoma Peripheral palisading with tumor-stroma retraction • Trichoblastoma Tumor lobule surrounded by fibroblastic stroma;…
Rhabdomyoma
Adult, fetal, and genital types Etiology/Pathogenesis • No association with tuberous sclerosis (unlike cardiac type) • Some fetal rhabdomyomas associated with nevoid basal cell carcinoma syndrome (Gorlin syndrome) Clinical Issues • Fetal type:…
