Intraosseous lipoma. A clinical, radiologic, and pathologic study of 5 cases.

Intraosseous lipoma is an uncommon tumor of bone with indistinct radiologic features that makes it diagnostically challenging to radiologists and pathologists. There is a need to familiarize these physicians with the radiographic and pathologic features of this lesion for the correct diagnosis. We described the radiologic and pathologic features of intraosseous lipoma in 5 women. In 4 patients, the tumors occurred in long bones, whereas in the fifth patient, the skull was involved. Patients' age ranged from 50 to 63 years. Plain radiographs of the long bones revealed well-circumscribed benign-appearing osteolytic lesions with sclerotic margins, whereas in the skull, a poorly defined lytic aggressive-looking lesion was observed. In the long bones, the lesions showed remodeling of the affected bone with matrix calcification, simulating bone infarcts. Microscopically, mature adipose tissue with fat necrosis, absence of hematopoietic elements, and dystrophic calcification corresponding to the calcified matrix seen on the plain radiographs were seen. The osteolytic skull lesion had large caliber thin-walled vasculature with occasional fibrin thrombi mimicking intramuscular hemangiomas of soft tissue. On plain radiographs, an intraosseous lipoma is usually seen as a rather benign-appearing osteolytic bone lesion with well-defined margins and a heavily calcified/ossified dense matrix. Plain radiographs alone cannot establish the diagnosis of intraosseous lipoma as it mimics several other benign and malignant bone lesions. Intraosseous lipoma often contains calcified necrotic fat with little mature adipose tissue and characteristically induces expansion/remodeling of the affected bone.

A case of monophasic synovial sarcoma presenting as a vulvar mass.

BACKGROUND: Synovial sarcoma is the fourth most commonly occurring sarcoma, accounting for 8-10% of all sarcomas. They arise from unknown pleuripotent stem cells that are capable of differentiating into mesenchymal and/or epithelial structures. Synovial sarcoma is characterized by specific chromosomal translocation t (X; 18)(p11, q11). CASE: We report the first case of monophasic synovial sarcoma arising in soft tissues of the vulva in a 33-year-old female. Complete excision of the mass was possible with tumor-free margins. CONCLUSION: Only four previous cases of biphasic synovial sarcoma arising in the vulva have been reported. The finding of the SYT-SSX2 translocation is generally associated with a better prognosis, besides tumor negative margins after excision offer the possibility of a better outlook for this patient.