Between 1974 and 1998, 34 patients with primary bone tumors and 28 with soft tissue tumors, all located in the foot, were surgically treated at our institutions. Of the 34 patients with a bone tumor, 27 (79%) had chondrogenic tumors: exostoses, 17; enchondromas, 7; benign chondroblastomas, 2 and chondrosarcoma, 1. This chondrosarcoma was misdiagnosed as a benign chondroblastoma at the initial biopsy. Five months after the initial curettage and bone grrafting, the tumor was recurred as a chondrosarcoma. This patient died with pulmonary metastasis another five months after the below the knee (BK) amputation. The differential diagnosis between benign chondrogenic tumors and low grade chondrosarcoma is very difficult as proposed by Mirra. Whereas the malignant tumor is very rare in the foot, the diagnosis of chondrogenic tumor should be made carefully. Of the 28 soft tissue tumors, diagnoses were giant cell tumor of tendon sheath or pigmented villonodular synovitis, 8; angioleiomyoma, 4; ganglion, 4; hemangioma, 2; miscellaneous benign tumors, 7 and soft tissue sarcomas (STS), 3. All patients with a STS were treated by a BK amputation, a partial foot amputation or a marginal resection, and died with pulmonary metastasis. However the function of the operated limb and the emotional acceptance were better in a patient with the less abrasion surgery.
Ossyfying periarticular lipoma is a very rare entity. Lipomas undergo involutional changes like chondrification, calcification and very rarely ossification. These changes result in altered clinical, radiological and histopathological features leading to diagnostic challenge in differentiation from the soft tissue tumor like synovial sarcoma, liposarcoma and rhabdomyosarcoma. We present a series of three cases of ossifying lipomas presenting as soft tissue tumor around the knee, shoulder and hip joints. All the tumors revealed calcification and ossification on plain X-rays and on MRI/CT Scans. Clinico-radiological evaluation lead to a similar diagnostic dilemma in our series and a confirmed diagnosis of ossifying lipoma became possible only after histopathology. All the three tumors were excised completely without any recurrence during last 3 1/2 years of follow-up. We recommend the early imaging by MRI/CT scan with closed core biopsy to exclude the malignant pathology and complete excision of the tumor with early mobilization of the adjacent joint.