CASE REPORTClear Cell Myomelanocytic Tumor of the Urinary BladderPan, Chin-Chen M.D.; Yu, I-Ting M.D.; Yang, An-Hang M.D., Ph.D.; Chiang, Hung M.D.Author Information From the Department of Pathology, National Yang-Ming University and Veterans General Hospital-Taipei, Taipei, Taiwan. Address correspondence and reprint requests to Chin-Chen Pan, MD, Department of Pathology, Veteran General Hospital-Taipei, No. 201, Sec. 2, Shih-Pai Rd., Taipei, 11217, Taiwan; e-mail: [email protected] The American Journal of Surgical Pathology: May 2003 - Volume 27 - Issue 5 - p 689-692 Buy Abstract Clear cell myomelanocytic tumors are a recently described neoplastic growth considered to be a member of the family of perivascular epithelioid cell tumor. These tumors have a predilection for falciform ligament/ligamentum teres. We report an additional case arising from the muscularis propria of the urinary bladder in a 33-year-old woman. The tumor consisted of clear to eosinophilic, epithelioid, and spindled cells arranged in fascicles or packets. A delicate vascular stroma was found among the nests. Immunohistochemically, the tumor cells were typically positive for HMB-45 and smooth muscle actin but negative for S-100 protein, Melan-A, desmin, and pan-cytokeratin. The patient has been free of the disease since the excision of the tumor 6 years ago. This case, in association with the expanding list of perivascular epithelioid cell tumor reported in different sites, suggests that this type of neoplasm may be ubiquitous. Copyright © 2003 Wolters Kluwer Health, Inc. All rights reserved.