Cytopathologic Characteristics of Epithelioid Vascular Malignancies

Abstract

Objectives: Epithelioid hemangioendothelioma (EHE) and epithelioid angiosarcoma (EAS) are rare vascular neoplasms that share many morphological characteristics on histology but demonstrate different clinical behavior. Given the many reported clinical and morphological features shared between EAS and EHE, we examined all cases of EAS and EHE diagnosed primarily on fine needle aspiration (FNA) at our three institutions that were confirmed by a tissue diagnosis. Study Design: A total of 29 cases from 25 patients were identified: 15 EHE from 11 patients and 14 EAS from 14 patients. Results: Many cytomorphological features existed on a spectrum that overlapped considerably between EAS and EHE cases. Common features between the two entities include epithelioid morphology and eccentrically placed nucleus. Intracytoplasmic lumens (ICL), a morphological feature that may suggest vascular origin, can be found in both entities but are not always present. Conclusions: Given the general absence of vascular cytomorphological features, such as ICL, the proper classification of these tumors depends on the successful use of immunoperoxidase markers such as factor VIII-related antigen, ERG, or CD31 as well as a high index of suspicion. The distinction between EAS and EHE on FNA alone is treacherous at best.

Cytologic features of angiosarcoma: A review of 26 cases diagnosed on FNA

“…As the malignant cells recapitulate endothelium, they may also entrap components of normal blood, including red and white blood cells as observed in our cohort and others in the literature . However, when the vacuoles are empty, they may mimic the mucin vacuoles of adenocarcinoma. This, in addition to cytokeratin expression, which, depending on the series, is seen in 21% to 100% of epithelioid angiosarcomas, may lead to their misdiagnosis as carcinoma …”

“…Typically, the presence of cytoplasmic vacuoles in epithelioid cells would favor a diagnosis of adenocarcinoma. However, as shown in this study as well as others, these cytoplasmic vacuoles (or lumina) are representative of early vascular lumina typical of angiosarcoma . Depending on the series, their frequency ranges from 100% to 0% .…”

“…The histologic features of angiosarcoma are well described, with tumors ranging from well‐differentiated, overtly vasoformative tumors to high‐grade, stroma‐poor, epithelioid neoplasms with little or no resemblance to normal vascular structures. Angiosarcomas are only rarely aspirated; hence, there is a dearth of large cytologic studies in the literature, with most studies being isolated case reports and small series . Interestingly, one of the largest series involved canines, in which these tumors are apparently frequent …”

Epithelioid hemangioendothelioma in pleural effusion

“…5,6,17 Because the two entities can share similar immunoprofiles, a definitive diagnosis of EHE vs. EAS typically requires examination of architecture on core biopsy material. EAS is an aggressive vascular malignancy, which can occur in similar sites as EHE such as bone, lung, liver, and soft tissue.…”

Cancer of unknown primary: Ancillary testing of cytologic and small biopsy specimens in the era of targeted therapy

“…Mesenchymal neoplasms and proliferations with epithelioid morphology can be mistaken for carcinomas and initially elude a proper workup . Neoplastic cells in such lesions may appear in fragments and/or as dispersed cells.…”