Pseudoangiosarcomatous Urothelial Carcinoma of the Urinary Bladder

Abstract

The pseudoangiosarcomatous pattern has been described mostly in cutaneous and some visceral squamous cell carcinomas and is unique for its striking morphologic resemblance to angiosarcoma. Herein, we describe the clinicopathologic features of 7 pseudoangiosarcomatous urothelial carcinomas that occurred in the urinary bladder. The patients included 6 men and 1 woman ranging in age from 47 to 87 years (median 70 y). The pseudoangiosarcomatous morphology was observed in 7 urothelial carcinomas including 3 with squamous differentiation and comprised 35% to 85% of the invasive tumor. Histologically, the pseudoangiosarcomatous carcinomas were characterized by tumor cell discohesion and lysis that created pseudolumina formations surrounded by attached residual tumor cells. Detached degenerating tumor cells variably admixed with inflammatory cells were common in the false lumina. Partly intact urothelial carcinoma nests contained irregular or cleft-like spaces and disintegrating tumor cells with stretched intercellular bridges. The tumor was commonly associated with a dense collagenous matrix, often surrounding the lytic nests. Similar tumor cell discohesion and breakdown were observed in 3 tumors with foci of squamous cell differentiation, distinguished by the presence of dyskeratosis and keratin formation. All 7 tumors contained other nonpseudoangiosarcomatous carcinoma components such as conventional urothelial carcinoma (5), squamous differentiation (4), sarcomatoid spindle cell carcinoma (2), small cell carcinoma (1), micropapillary carcinoma (1), and glandular differentiation (1). The pseudoangiosarcomatous urothelial carcinomas were all (7/7) diffusely CK7 positive, most (6/7) were GATA3 positive, and none (0/7) expressed vascular-associated markers. There was no evidence to suggest that apoptosis (by TUNEL assay and cleaved caspase-3 immunostaining) or loss of the adhesion molecules CD138 and e-cadherin were possible causes for the tumor cell discohesion and breakdown. All 7 tumors were high stage at cystectomy and included 1 pT3a, 2 pT3b, and 4 pT4a tumors, and 3 had pelvic lymph node involvement. Follow-up data available in 6 cases revealed a poor outcome with an overall median survival of 8.5 months. In conclusion, we present an unusual morphology of bladder carcinoma that has a striking resemblance to a malignant vasoformative tumor. Our series showed that bladder pseudoangiosarcomatous carcinoma morphology is associated with a higher tumor stage at cystectomy, commonly admixed with other aggressive carcinoma variant morphologies, and portend a poorer outcome. Knowledge of this pattern is also important to avoid misdiagnosis, particularly in limited tissue samples.

Variants and new entities of bladder cancer

“…The tumour is frequently associated with a dense variable collagenic matrix. The tumour cells show positive immunostaining for p40, CK7 and GATA3, supporting urothelial origin …”

“…The pseudoangiosarcomatous pattern is unique for its histological resemblance to angiosarcoma (Figure ). It is seen more frequently in males with poor outcome (age range = 47–87 years) . Pseudoangiosarcomatous carcinoma may be associated with conventional urothelial carcinoma with divergent differentiation, sarcomatoid carcinoma, small‐cell carcinoma and micropapillary carcinoma.…”

“…It is seen more frequently in males with poor outcome (age range = 47-87 years). 101 Pseudoangiosarcomatous carcinoma may be associated with conventional urothelial carcinoma with divergent differentiation, sarcomatoid carcinoma, small-cell carcinoma and micropapillary carcinoma. Histologically, the pseudoangiosarcomatous carcinomas are characterised by tumour cell discohesion (acantholytic) that creates pseudolumina formations surrounded by attached residual tumour cells.…”

“…The tumour cells show positive immunostaining for p40, CK7 and GATA3, supporting urothelial origin. 101…”

Sarcomatoid Urothelial Carcinoma of the Bladder: Analysis of 28 Cases With Emphasis on Clinicopathologic Features and Markers of Epithelial-to-Mesenchymal Transition

“…10 Additional variations included the presence of myxoid and pseudoangiosarcomatous features in a subset of cases. 19 The carcinomatous component commonly showed rhabdoid morphology, 20 but chordoid, 21 squamous, and lymphoepithelioma-like 22,23 patterns were also seen. Chordoid and myxoid features were significantly associated with reduced survival in this study.…”