A 66 year old female with past history of breast cancer, treated by breast conserving therapy and radiation, presented with vague subareolar fullness. H&E images from core biopsy and mastectomy.

Contributed By: Kamaljeet Singh MD

Please choose:

  • Spindle cell metaplastic carcinoma

  • Angiosarcoma

  • Melanoma

  • Malignant phyllodes

 

 

 

 

 

 

The answer is Angiosarcoma.

Discussion

Postradiation angiosarcoma of breast (PRAB)

The core biopsy shows subareolar tissue comprising of smooth muscle bundles and a malignant spindle cell proliferation with areas of hemorrhage. The tumor cells are forming vascular structures and hyperchromatic nuclei protrude into the lumen. Focally the tumor cells have nested architecture and epithelioid cytology. The tumor cells show marked nuclear hyperchromasia and mitotic activity.

Mastectomy (last pictures) shows markedly cellular proliferation replacing the subareolar and deeper breast parenchyma.  By immunohistochemistry tumor cells were positive for CD31, D2-40 and ERG, consistent with angiosarcoma. With clinical history of radiation and aforementioned histological features the diagnosis is postradiation angiosarcoma of breast (PRAB).

PRAB occurs in the radiation field with an average latent period of 5- 6 years, with rare cases reported in 1-2 years. Angiosarcoma can arise in a setting of chronic lymphedema (Stewart-Treves Syndrome). Primary angiosarcoma of breast often involve breast parenchyma of younger females and they are less common than PRAB. PRAB can be diffuse, multifocal and they are predominantly skin/dermal based tumors. On histology PRAB shows vasoformative growth pattern, spindle and epithelioid cytology, tissue infiltration, prominent mitosis, blood lakes and necrosis. Well-differentiated PRAB can be difficult to distinguish from a benign vascular lesion. Tests for myc gene amplification (FISH and IHC) and loss of H3K27me3 can help in morphologically ambiguous vascular proliferations. Grading of PRAB has been controversial and many authors have considered it to be non-prognostic.  

Reference: WHO classification of Tumours Editorial Board. Breast tumours. Lyon (France): IARC; 2019 (pages 197-199).