Solitary Myofibroma of the Bladder Trigone in a 3-Month-Old Patient: First Case Report

Figure 4

Pathology. (a–d) (Haematoxylin/eosin): nodular proliferation with superficial normal urothelium; (e) peripheral zones have myoid short fascicles/whorls/nodules of plump myofibroblasts with pale pink cytoplasm and long, tapering nuclei with vesicular chromatin and 1-2 small nucleoli, but no atypia or pleomorphism, often associated with hyalinization, and whorls/nodules can have a vaguely chondroid or chondromyxoid appearance; (f) central zones between the peripheral myoid nodules display cellular areas of round, polygonal, or spindle cells with scant cytoplasm, hyperchromatic nuclei, arranged around thin walled branching ectatic “hemangiopericytic” vessels; often calcification, necrosis, and hyalinization; often apparent subendothelial intravascular growth but still benign with minimal mitotic activity.

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