Case Number : Case 840 - 5th September Posted By: Guest

Cutaneous angiosarcoma, possibly postradiation.

[quote name='Romualdo' timestamp='1378372323']
Cutaneous angiosarcoma, possibly postradiation.
[/quote]
Agree!

Epithelioid angiosarcoma on top of differential, with nice pseudoglandular pattern. Perhaps radiation tx induced changes in the background.

Agree. Angiosarcoma.

High grande angiosarcoma, postradiation (probably).

I echo Romualdo's words.

Epithelioid angiosarcoma, mostly post radiation ..

[size=3]Epithelioid angiosarcoma. (Looks like we are all in agreement! )

The predominantly polygonal and rounded cells show prominent nucleoli, pleomorphic size/shape, moderate to high nuclear/cytoplasmic ratios, and mitotic activity. Architecture shows infiltrative single cells and fascicles weaving through collagen bundles, with some single, spindled tumor cells closely applied to the surface of collagen bundles (promontory sign) at the peripheries of the infiltrate. Poorly formed large blood-filled vascular spaces are lined by one or more layers of polygonal tumor cells that show tombstone-like intracellular separation artefact. Intracellular spaces packed with red cells are present in some tumor cells.

I don't think it applies in this case given the classic histology, but the differential would usually include Kaposi's sarcoma (often positive for CD31), epithelioid hemangioendothelioma, primary breast carcinoma, or other metastatic carcinoma/melanoma simulating angiosarcoma. Immunostaining will help confirm the diagnosis.

Angiosarcoma is (like metastatic melanoma) notorious for occasionally mimicking other, less aggressive neoplasms such as breast carcinoma* or metastatic renal cell carcinoma, especially if there is common, anomalous positive staining for cytokeratins such as CK7, positive staining for renal cell carcinoma marker CD10 -- or anomalous negative staining for CD34-- to trap the unwary.** (CD31 is, in my experience, a reasonably reliable positive stain, but hanging the entire diagnosis on any one stain may be unwise for cases of equivocal AS).[/size]

[size=3]* [url="http://www.ncbi.nlm.nih.gov/pubmed/21124204"]Angiosarcoma with pseudoepidermotropism in a patient with breast cancer: a mimic of epidermotropic metastatic adenocarcinoma.[/url] A[i]m J Dermatopathol. 2011 Jun;33(4):400-2.[/i][/size]
[font=arial,helvetica,sans-serif][size=3]** [url="http://www.ncbi.nlm.nih.gov/pubmed/19813270"]Epithelioid angiosarcoma: a neoplasm with potential diagnostic challenges.[/url] [i]Diagn Cytopathol. 2010 Feb;38(2):154-8[/i][/size][/font]
[size=3][font=arial,helvetica,sans-serif]** [url="http://www.ncbi.nlm.nih.gov/pubmed/22943673"]The co-expression of cytokeratin and p63 in epithelioid angiosarcoma of the parotid gland: a diagnostic pitfall.[/url][i]Diagn Pathol. 2012 Sep 3;7:118.[/i][/font][/size]

Just a couples of notes from the profane. According to soft tissue gurus (including Chris Fletcher) angiosarcomas at visceral location are far often more positive for keratins than those occurring in the skin. An expanded spectrum of cutaneous epithelioid angiosarcoma (and the differential thereof entailed) has been reported a few years ago by Carlos Bacchi et al in the AJSP 2010; 34(9):1334-43.

Epithelioid angiosarcoma. Keratin was negative in this case.