Vascular Lesions



Vascular Lesions






10.1 PERILOBULAR CAPILLARY HEMANGIOMA VS. ANGIOLIPOMA

















































Perilobular Capillary Hemangioma


Angiolipoma


Age


Middle age or older women


Any age


Location


Anywhere in the breast


Breast subcutaneous tissue, rarely mammary parenchyma


Presentation


Incidental finding


Painful dermal nodules, may be multiple


Imaging findings


None or small nodular density


None or rarely nodular density


Etiology


Unknown


Unknown


Histology




  1. Well-circumscribed proliferation of thin-walled capillaries that may involve the intralobular or extralobular stroma (Fig. 10.1.1)



  2. Incorporates lobular unit(s) but does not invade epithelial structures (Figs. 10.1.2, 10.1.3, 10.1.4)



  3. Capillaries are lined by attenuated endothelial cells with small nuclei devoid of atypia (Fig. 10.1.5)




  1. Well-circumscribed lesion composed of an admixture of mature adipose tissue and noninfiltrative small vascular spaces (Figs. 10.1.6 and 10.1.7)



  2. Vascular spaces may be compressed and slit-like (Fig. 10.1.8)



  3. Adipose tissue is an integral component of the lesion (Fig. 10.1.9)



  4. Vascular spaces lined by bland endothelial cells containing intravascular hyaline microthrombi (Fig. 10.1.10)


Special studies


None


None


Treatment


None, excision unnecessary


None, excision not required unless painful


Clinical implication


None, benign incidental finding


None







Figure 10.1.1 Perilobular capillary hemangioma: Well-circumscribed proliferation of small vessels that incorporates a lobular unit.






Figure 10.1.6 Angiolipoma is nodular and well-circumscribed, composed of mature adipose tissue and noninfiltrative, small vessels.







Figure 10.1.2 The capillaries may involve intralobular and extralobular stroma in a perilobular capillary hemangioma.






Figure 10.1.3 The thin-walled capillaries of perilobular capillary hemangioma incorporate the lobular unit(s) but do not invade epithelial structures.






Figure 10.1.4 Perilobular capillary hemangioma has a lobulated interface with the surrounding mammary parenchyma and remains circumscribed in areas involving extralobular stroma.






Figure 10.1.7 In angiolipoma, the vessels are small, densely packed, and congested.






Figure 10.1.8 The small vascular spaces in angiolipoma are tightly opposed resembling granulation tissue.






Figure 10.1.9 Bland endothelial cells line the vessels of angiolipoma; microthrombi are common.







Figure 10.1.5 The capillaries of perilobular capillary hemangioma are lined by attenuated endothelial cells with small nuclei devoid of atypia.






Figure 10.1.10 The endothelial cells are occasionally spindled in angiolipoma.



10.2 PERILOBULAR CAPILLARY HEMANGIOMA VS. ATYPICAL VASCULAR LESION

















































Perilobular Capillary Hemangioma


Atypical Vascular Lesion


Age


Middle age or older women


Middle age and older women, (usually sixth decade)


Location


Anywhere in the breast


Breast skin


Presentation


Incidental finding


Papules or plaques appearing several years (average 3-4 y) following radiation therapy; red-brown or pink


Imaging findings


None, rarely nodular density


May show skin thickening


Etiology


Unknown


Radiation exposure, often for breast cancer


Histology




  1. Well-circumscribed proliferation of thin-walled capillaries that may involve the intralobular or extralobular stroma (Figs. 10.2.1, 10.2.2, 10.2.3)



  2. Incorporate lobular unit(s) but do not invade epithelial structures (Figs. 10.2.1, 10.2.2, 10.2.3, 10.2.4)



  3. Capillaries are lined by attenuated endothelial cells with small nuclei devoid of atypia (Fig. 10.2.5)




  1. Localized, often wedge-shaped collection of haphazardly arranged and focally dilated vascular spaces in dermis. May be very subtle (Figs. 10.2.6 and 10.2.7)



  2. Vascular spaces may have a complex branching pattern and may be anastomosing (Fig. 10.2.8)



  3. The vascular spaces are confined to the dermis and lined by single layer of plump endothelial cells with nuclear hobnailing and hyperchromasia, but no mitoses (Fig. 10.2.9)



  4. Vessels suggest an infiltrative process; however, overall small size and circumscription support a diagnosis of atypical vascular lesion (Fig. 10.2.7)


Special studies


None


None to distinguish from capillary hemangioma


Treatment


None, excision unnecessary


Atypical vascular lesions should be excised with the aim of obtaining negative margins


Clinical implication


None, benign incidental finding


Following complete excision, the majority pursue a benign clinical course with a few cases reportedly recurring locally or progressing to angiosarcoma








Figure 10.2.1 This perilobular capillary hemangioma is an inconspicuous proliferation of dilated capillaries present in the specialized and adjacent nonspecialized connective tissue of several adjacent lobular units.






Figure 10.2.2 The capillaries may involve intralobular and extralobular stroma, but the lesion is architecturally circumscribed.






Figure 10.2.3 The thin-walled capillaries of perilobular capillary hemangioma frequently incorporate the acini of lobular units but do not invade epithelial structures.






Figure 10.2.6 Atypical vascular lesion, showing a characteristic wedge-shaped collection of haphazardly arranged and focally dilated vascular spaces in the dermis.






Figure 10.2.7 The vessels in atypical vascular lesions are haphazardly arranged and do not contain red blood cells: there is no red cell extravasation.






Figure 10.2.8 The vascular spaces are irregularly placed and separated by small bundles of dermal collagen.







Figure 10.2.4 Attenuated endothelial cells with small nuclei devoid of atypia line the capillaries of perilobular capillary hemangioma.






Figure 10.2.5 The lobular units involved by perilobular capillary hemangioma are frequently atrophic.






Figure 10.2.9 An atypical vascular lesion lined by plump endothelial cells. Nuclear hobnailing and hyperchromasia are frequently observed; however, overt nuclear atypia, endothelial multilayering, mitotic activity, and infiltration of the subcutis and breast parenchymal structures are absent.



10.3 ATYPICAL VASCULAR LESION VS. POSTRADIATION ANGIOSARCOMA, LOW-GRADE HISTOLOGY

















































Atypical Vascular Lesion


Postradiation Angiosarcoma, Low-Grade Histology


Age


Middle age and older women (usually sixth decade)


Women over 50 y of age (approximately 20 y older than women with primary angiosarcoma), time to diagnosis ranges from 2.5 to 11.5 y (median 4.5 y) after radiation therapy; risk of developing postradiation angiosaroma is approximately 0.3%


Location


Breast skin


Breast skin, may extend into adjacent mammary parenchyma


Presentation


Papules or plaques appearing several years (average 3-4 y) following radiation therapy; red-brown or pink


Multifocal, cutaneous, purple-blue and erythematous plaques, papules, or nodules within the radiation field which may secondarily involve adjacent breast parenchyma


Imaging findings


Skin thickening; none


None or skin thickening; associated ill-defined density with involvement of breast parenchyma; magnetic resonance imaging (MRI) may be useful in defining the size


Etiology


Radiation exposure, usually for breast cancer


Radiation treatment for breast cancer


Histology




  1. Localized, often wedge-shaped collection of haphazardly arranged and focally dilated vascular spaces in dermis. May be very subtle (Fig. 10.3.1)



  2. Vascular spaces may have a complex branching pattern and be anastomosing (Figs. 10.3.2 and 10.3.3)



  3. The vascular spaces are confined to the dermis and lined by a single layer of plump endothelial cells with nuclear hobnailing and hyperchromasia, but no mitoses (Fig. 10.3.4)



  4. Vascular spaces separated by small bundles of dermal collagen



  5. Vessels suggest an infiltrative process; however, overall small size and circumscription support a diagnosis of atypical vascular lesion




  1. Complex, anastomosing vascular channels that infiltrate the dermis and/or the breast parenchyma (Figs. 10.3.5 and 10.3.6)



  2. Well-defined vascular spaces lined by cells with prominent nuclei that protrude into the vascular lumen (Figs. 10.3.7 and 10.3.8)



  3. Subtle permeation of adipose tissue mimics angiolipoma



  4. May contain atypical vascular lesion-like areas in the periphery of the lesion; distinction from atypical vascular lesion on core biopsy specimen may be difficult, requiring excision for diagnosis


Special studies


Absent c-myc expression by immunohistochemistry and lack of myc amplification by fluorescence in situ hybridization (FISH) distinguish from angiosarcoma with high specificity; immunohistochemistry for ERG may reassure a limited extent of the process and circumscription but does not distinguish from angiosarcoma. Immunohistochemical staining for vascular markers does not distinguish from angiosarcoma.


MYC amplification present in >50% of postradiation angiosarcomas but absent in atypical vascular lesions. Immunohistochemistry for c-myc shows nearly 100% concordance with MYC amplification as detected by FISH. Immunohistochemical expression of vascular markers does not distinguish from atypical vascular lesions.


Treatment


Atypical vascular lesions should be excised with the aim of obtaining negative margins. When diagnosed on needle core biopsy, excision is generally warranted to exclude angiosarcoma.


Total mastectomy; wide excision alone is associated with high recurrence rates. Radiotherapy and chemotherapy ineffective.


Clinical implication


Following complete excision, the majority pursue a benign clinical course with a few cases reportedly recurring locally or progressing to angiosarcoma. Distinction from angiosarcoma is critical to avoid excessive surgery and inappropriate prognostication.


Postradiation angiosarcoma, regardless of grade, has a poor prognosis with a mean survival of 1-2 y

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Sep 23, 2018 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Vascular Lesions

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