Granular cell angiosarcoma

Granular cell cutaneous epithelioid angiomatous nodule

Cutaneous epithelioid angiomatous nodule is an uncommon vascular lesion usually described as composed of epithelioid endothelial cells with vesicular nuclei and eosinophilic cytoplasm. A granular cell variant has not been previously described. Endothelial cells can present with granular cytoplasm as documented with reports of granular cell angiosarcoma. The granularity is thought to be due to increased intracytoplasmic lysosomes. We present a case of a benign superficial vascular lesion composed of a sheet-like proliferation of epithelioid endothelial cells with distinctly granular cytoplasm confirmed as of endothelial origin with positive staining for CD31 and ERG.

Cutaneous epithelioid hemangiosarcoma with granular cell differentiation in a dog: a case report and review of the literature

We report a case of cutaneous epithelioid hemangiosarcoma in a dog in which the majority of the neoplastic cells displayed histologic and ultrastructural features similar to those seen in granular cell tumors (GCTs). This intersection of hemangiosarcoma and granular cell change adds to the argument that GCTs are heterogeneous in histologic origin and underlines the fact that pathologists should not consider all GCTs as a single entity. The combination of histology in typical areas of the tumor with ultrastructural changes and the correct immunohistochemical markers can facilitate the accurate diagnosis of tumors with granular cell differentiation. Besides characteristic intracytoplasmic PAS-positive granules and ultrastructural proteinaceous accumulation within single membrane vesicles (presumably lysosomes and phagolysosomes), we suggest the following combination of markers for the diagnosis of granular cell angiosarcoma and/or hemangiosarcoma: vimentin positive, NSE and/or S100 negative, CD31 positive. We propose that the histologic granular appearance represents a metabolic defect of the neoplastic cells, which supports variability in cell origin for granular cell differentiation.

The spectrum of rare morphological variants of cutaneous epithelioid angiosarcoma

AIMS

Unusual cytoplasmic alterations have recently been reported in poorly differentiated cutaneous angiosarcoma, making an accurate diagnosis challenging. As these tumours remain poorly documented, we aimed to study their clinicopathological characteristics more comprehensively.

METHODS AND RESULTS

Six cutaneous angiosarcomas with unusual cytoplasmic alterations were identified from referral files. All tumours arose as nodules or plaques (range: 05-195 mm) on sun-damaged skin of the head and neck of elderly males (median age: 76.5 years). Histologically, the tumours were composed of enlarged epithelioid cells showing prominent signet ring (n = 3), foam (n = 2) or granular cell (n = 1) change. Vasoformative elements were only focally noted. By immunohistochemistry, all tumours expressed CD31 and avian v-ets erythroblastosis virus E26 oncogene homologue (ERG). Foam cell change was associated with additional expression of CD68 and CD163. Follow-up (median: 8 months) showed death from disease (n = 1), death from a gastrointestinal bleed (n = 1), and a cutaneous metastasis (n = 1). Only two patients are alive with no evidence of disease.

CONCLUSIONS

Our findings outline the morphological spectrum of cytoplasmic change in cutaneous angiosarcoma. Awareness and a high degree of suspicion in the context of tumours affecting sun-damaged skin of the elderly are necessary to direct appropriate immunohistochemical work-up with inclusion of the endothelial cell markers CD31 and ERG.

[Cutaneous angiosarcoma: new aspects]

Cutaneous angiosarcoma is an aggressive endothelial cell neoplasm with a high associated mortality. Reliable and confident diagnosis is necessary but frequently challenging due to the wide morphological spectrum and broad differential diagnosis of the disease. Furthermore, the final diagnosis often relies on immunohistochemical evidence of endothelial cell differentiation which is further complicated by the lack of sensitivity and specificity of conventional endothelial cell markers. The following article outlines the clinical and histological spectrum of cutaneous angiosarcoma with emphasis on novel findings relating to immunohistochemistry and molecular genetics in the context of the relevant differential diagnosis.