LEIOMYOSARCOMA BONE METASTASIS - A CASE-R EPORT

Introduction Bone leiomyosarcoma is a rare tumor, whether it may be pr imary or secondary. The authors report on the case of a woman, aged 67 , admitted in January 1992 complaining of pain in the left hip and the upper end of the femur. Case report In 1985 the patient underwent sur gical excision of a soft tissue tumor in the right thigh, histological ly diagnosed as a benign-fibrous tumor. This lesion recurred locally f our times and repeated excisions were performed throughout the years, always with a histological diagnosis of a benign lesion. On admission to hospital, the physical examination as well as laboratory data and p lain roentgenograms were unremarkable. Both tomography and MRI showed a lesion in the upper end of the left femur. An isotopic bone scan sho wed marked increased uptake in the left hip extending to the femoral d iaphysis. An open biopsy was performed for histology, immunohistochemi stry and electron microscopy. A diagnosis of metastatic leiomyosarcoma was made. The retrospective histological examination of specimens of the soft tissue tumor excised in 1985 showed the same immunohistochemi cal features of the contralateral leiomyosarcoma. On this basis, one s tage resection of the left hip and the upper end of the femur was perf ormed and a Kotz modular prosthesis was inserted. Postoperative healin g was achieved without any complications and the function of the opera ted limb was satisfactory. Three months after the operation pulmonary lesions were noted on chest radiographs and CT scan. The patient died two years after the first admission for widespread metastasis. Discuss ion In the reported case, the bony metastasis appeared to be the prese nting finding of the soft tissue tumor of the controlateral thigh. Thi s presentation is rare in previously published series. The misdiagnosi s of the primary tumor had caused focal recurrences, and an increased malignity occurred. According to the literature, a soft tissue leiomyo sarcoma can be easily confused with other spindle cell lesions. Theref ore an accurate histological and ultrastructural diagnosis is necessar y for adequate surgical treatment.