Sarcomatoid Carcinoma with Angiosacromatous Differentiation of the Bladder Mimicking Primary Angiosarcoma: A Diagnostic Challenge

Abstract

Sarcomatoid urothelial carcinoma (UC) is a high-grade aggressive subtype of UC defined by the WHO classification of tumours of the Urinary System and Male Genital Organs with “the presence of areas that are indistinguishable from sarcoma” [1]. In fact, it is a biphasic neoplasm with both; malignant epithelial and mesenchymal differentiation. Heterologuous components have been described, among which angiosarcoma is exceedingly rare [1,2]. Given its poor prognosis and aggressive clinical behavior, this subtype of UC should be distinguished from other bladder carcinoma, and further immunophenotypic study and /or molecular work-up must be performed. Thus, accurate diagnosis is mandatory for treatment purposes.