Solitary fibrous tumor is a rare soft-tissue neoplasm that is capable of metastasis of fibroblastic/myofibroblastic cell origin. Although most of the cases are pleural in origin, extrapleural locations are reported with increasing frequency. Extrapleural cases are mostly seen in retroperitoneal location. Malignant forms are much rarer.
A 61-year-old male patient was admitted with complaints of dysuria, low back pain and constipation. Radiological investigation revealed a retroperitoneal mass lesion. The excised mass was macroscopically well-circumscribed without capsule and was measured as 12 × 10 × 8 cm. The tumor was hypercellular and it contained necrosis areas. Peripheral soft tissue invasion was noted in the tumor. Tumor showed a vascular pattern that reminiscent of a hemangiopericytomatous pattern. Tumor were positive with CD34, bcl-2, EMA, vimentin, PAX8 and STAT6 in immunohistochemical analysis. The case was diagnosed as retroperitoneal solitary fibrous tumor. The tumor was compatible with the malignant category due to widespread necrosis, increased cellularity and high mitotic index.
A 61-year-old male patient was admitted with complaints of dysuria, low back pain and constipation. Radiological investigation revealed a retroperitoneal mass lesion. The excised mass was macroscopically well-circumscribed without capsule and was measured as 12 × 10 × 8 cm. The tumor was hypercellular and it contained necrosis areas. Peripheral soft tissue invasion was noted in the tumor. Tumor showed a vascular pattern that reminiscent of a hemangiopericytomatous pattern. Tumor were positive with CD34, bcl-2, EMA, vimentin, PAX8 and STAT6 in immunohistochemical analysis. The case was diagnosed as retroperitoneal solitary fibrous tumor. The tumor was compatible with the malignant category due to widespread necrosis, increased cellularity and high mitotic index.
In order to increase our knowledge about the clinicopathological features and biological nature of these tumors, there is a need more cases of extrathoracal/extrapleural solitary fibrous tumor.