A case of capillary hemangioblastoma located in the peripheral soft tissue of the inner ankle in a 74-year-old woman is presented. The tumor was an unencapsulated but sharply circumscribed nodule 2.5 cm in size, of a yellow-white color. It showed reddish-brown spots with small cysts up to 2 mm filled with blood. Grossly the tumor was not attached to any peripheral nerve. Signs of von Hippel-Lindau's disease were excluded by thorough clinical evaluation. No additional tumor or erythrocytosis was found in the patient clinically. Immunohistochemically, the tumor stromal cell reacted strongly with antibodies to S-100 protein, NSE, and calponin and they were negative with antibodies to GFAP, CD34, CD31, cytokeratins, actin, desmin, EMA, and HMB-45. Endothelium of the capillaries reacted positively with antibodies to CD31, CD34, and Factor VIII-related protein. Capillary pericytes were actin-positive. All cells of the tumor stained positively with antibody to vimentin. MIB1 antibody reacted only in very few cells (<1%). Ultrastructurally, the stromal cells contained electron-lucent cytoplasm with lipid droplets, a small amount of rough endoplasmic reticulum, and glycogen particles. No electron-dense structures typical of secretory granules were seen in the stromal cells. No mutation of coding sequence of VHL gene was found.

Department of Pathology Faculty Hospital Pilsen Czech Republic

References provided by Crossref.org

Familial syndromes associated with testicular and paratesticular neoplasms: a comprehensive review

Recurrent YAP1-TFE3 Gene Fusions in Clear Cell Stromal Tumor of the Lung

Sporadic renal hemangioblastoma with CA9, PAX2 and PAX8 expression: diagnostic pitfall in the differential diagnosis from clear cell renal cell carcinoma

Renal angiomyoadenomatous tumor: morphologic, immunohistochemical, and molecular genetic study of a distinct entity