Primary intra-osseous liposarcoma of the femur: a case report.

We report a rare case of an intra-osseous liposarcoma of the proximal femur. A 26-year-old man presented with a 6-month history of left groin pain radiating to the knee and an antalgic gait. Radiology showed a predominantly fatty lesion in the medial aspect of the femoral neck extending toward the lesser trochanter; most of the marrow in the femoral neck had been replaced without evidence of an extra-osseous mass; and the posterior cortex had been destroyed. Histological and immunohistochemical analyses of the tumour after open biopsy were indicative of high-grade liposarcomatous malignancy. After exclusion of any other primary tumour foci or metastases on regional and whole-body magnetic resonance images, the diagnosis of a high-grade intra-osseous primary liposarcoma of the proximal femur was made. The patient received 2 preoperative courses of neoadjuvant doxorubicin, cisplatin and methotrexate. After proximal femoral replacement following en bloc excision of the proximal femur, 4 more cycles of adjuvant ifosfamide and etoposide were given. At the 16-month follow-up, he remained independently ambulatory, with no local or distant recurrence. Tissue diagnosis and multimodal imaging, rather than any single radiological investigation, are important in making the diagnosis.