Pseudosarcomatous Proliferation of Cx43- and Kit-Expressing Interstitial Cell in the Urinary Bladder

Abstract EN

The authors report a case showing proliferation of KIT- and connexin 43-expressing mesenchymal cells of the urinary bladder.

A 75-year-old woman had an ulcerated endophytic mass (size, approximately 2 × 2 cm) in the left posterolateral wall.

She underwent transurethral resection and subsequent partial cystectomy.

The suburothelial mass extended to the muscularis propria.

The histopathological analysis revealed spindle-shaped mesenchymal cells that were loosely arranged with myxoid stroma and showed a focal compact fascicular arrangement.

In the immunohistochemical analysis, these spindle cells were stained with specific antibodies to KIT and connexin 43.

The patient is currently free of disease at 5 years after operation.

The proliferating spindle cells in the present case might represent a phenotype of interstitial cells of the lamina propria.