BACKGROUND: Solitary fibrous tumor (SFT) is an uncommon but well-characterized soft tissue tumor that was first described as a pleural lesion and now is considered ubiquitous, having been detected at many extra-pleural sites (abdominal cavity, orbit, upper respiratory tract, and oral cavity). Histologically, SFT may show wide morphological variability of both its cellular and stromal components, which may lead to incorrect diagnosis especially when dealing with small incisional biopsies. MATERIALS: We report on the clinical, morphological and immunohistochemical features of eight SFT occurring in the oral cavity. RESULTS: Microscopically all eight tumors showed widely variable morphological features in terms of cellular density and stromal architecture, thus simulating benign fibrous histiocytoma, schwannoma, hemangiopericytoma or low-grade sarcoma in distinct areas of the same lesion. Among these eight cases, five had been diagnosed as SFT, two as benign fibrous histiocytoma and one as low-grade sarcoma. CONCLUSIONS: In consideration of the heterogeneous morphological appearance of SFT, inaccurate sampling of the mass may lead to misdiagnosis and inappropriate treatment. Therefore, an accurate histological examination of multiple tissue sections is advised, along with the use of appropriate immunostains.
BACKGROUND: Solitary fibrous tumor (SFT) is an uncommon but well-characterized soft tissue tumor that was first described as a pleural lesion and now is considered ubiquitous, having been detected at many extra-pleural sites (abdominal cavity, orbit, upper respiratory tract, and oral cavity). Histologically, SFT may show wide morphological variability of both its cellular and stromal components, which may lead to incorrect diagnosis especially when dealing with small incisional biopsies. MATERIALS: We report on the clinical, morphological and immunohistochemical features of eight SFT occurring in the oral cavity. RESULTS: Microscopically all eight tumors showed widely variable morphological features in terms of cellular density and stromal architecture, thus simulating benign fibrous histiocytoma, schwannoma, hemangiopericytoma or low-grade sarcoma in distinct areas of the same lesion. Among these eight cases, five had been diagnosed as SFT, two as benign fibrous histiocytoma and one as low-grade sarcoma. CONCLUSIONS: In consideration of the heterogeneous morphological appearance of SFT, inaccurate sampling of the mass may lead to misdiagnosis and inappropriate treatment. Therefore, an accurate histological examination of multiple tissue sections is advised, along with the use of appropriate immunostains.