Cutaneous epithelioid angiosarcoma: a neoplasm with potential pitfalls in diagnosis.

Angiosarcoma (AS) is a rare neoplasm. Cutaneous AS is the most common form of AS. The epithelioid variant of the disease, however, is a rare entity. This subset can histologically mimic non-vascular neoplasms and impose serious challenges in reaching the correct diagnosis. We present five patients with cutaneous epithelioid angiosarcoma (EAS); in none, the clinical diagnosis included a vascular lesion. Three patients had history of breast conservation surgery with/without radiation therapy. Other patients had no previous radiation, and there was no lymphedema in any of the cases. The histopathological examination of the biopsy specimens by hematoxylin and eosin method was not suggestive of a malignant vascular neoplasm initially and the differential diagnoses included carcinoma, malignant melanoma and atypical lymphoid infiltrate. Only after performing immunohistochemical studies that included vascular markers, a definitive diagnosis was possible. Some cases showed unusual histopathological features. Cutaneous EAS is a rare variant of cutaneous AS that can mimic a variety of more common, non-vascular neoplasms, creating a major pitfall in the diagnosis. A careful and thorough histopathological examination and a high index of suspicion, along with appropriate immunohistochemical evaluation, can help reach a correct diagnosis and provide optimal patient care.