Malignant degeneration of an osteochondroma with unusual intra-bursal invasion

Femoral osteochondroma responsible for ischiofemoral impingement, bursitis, and secondary lipoma arborescens mimicking malignant transformation

We present the case of a 53-year-old woman with a known history of hereditary multiple exostosis disease referred for further imaging work-up after ultrasound and computed tomography leading to the suspicion of malignant transformation of an osteochondroma (exostosis) located on the posteromedial aspect of the right proximal femur. Imaging examinations suggested an ischiofemoral impingement resulting in a secondary bursitis associated with the development of an internal lipoma arborescens. This rare association explained the complexity of the diagnosis. Magnetic resonance imaging (MRI) played a key role in correctly identifying this benign complication of the osteochondroma and in distinguishing those observations from a secondary exostotic chondrosarcoma. MRI findings were subsequently confirmed at surgery and pathological examination.

One-stage surgical excision of a huge bilateral multiple osteochondroma of the hip: a case report

Osteochondroma or hereditary multiple exostoses is the most common benign bone tumor and is usually found in young patients. Osteochondromata of the proximal femur or hip have been reported in 30% to 90% of patients with hereditary multiple exostoses. This article presents a 25-year-old-male referred to our orthopedic clinic with a complaint of pain in both groins for the last four years which has deteriorated in the past 6 months by limitation of range of motion. Radiographic findings were consistent with huge hip osteochondroma and a histopathological report confirmed the diagnosis. This was a case of a huge bilateral osteochondroma of the hip originating from the posterior of the hips to the neck of the femur and hip joints and part of proximal of femur, that underwent one-stage surgical excision of the tumor with posterior approach and tumor resection. As we know, this case of bilateral huge hip osteochondromas has rarely been presented previously by someone who has undergone one-stage surgery treatment of a tumor this size. Bilateral hip osteochondroma is a rare condition and we showed that one-stage excision can be performed successfully.

Osteochondroma of the hip with adjacent bursal chondromatosis

It is well established that irregular bursae can form adjacent to an osteochondroma (bursa exostotica) as a result of mechanical irritation and that these bursae can be complicated by inflammation, hemorrhage, or infection. Bursal chondromatosis is a rare complication, with only seven published cases in the literature according to our searches. We present the case of a 53-year-old female who presented with slowly progressive left hip/thigh pain and was found to have an osteochondroma arising from the lesser trochanter with numerous ossified bodies in the adjacent soft tissues. MRI demonstrated osteochondral bodies in a fluid-filled bursa adjacent to the osteochondroma, with several of the bodies noted to be fairly displaced from the osteochondroma cartilaginous cap. At surgery, the osteochondroma was removed and numerous bodies of varying sizes were excised, some of which were noted to be adherent to the bursal lining and others that were separated/distant from the cartilage cap. The question arises as to whether this process represents bursal chondromatosis resulting from benign neoplasia of cells lining the abnormal bursa, "cartilage shedding" from the osteochondromatous cap, or both. The purpose in presenting this case is to introduce a rare complication of an osteochondroma, demonstrate that soft tissue calcification and osteochondral densities displaced from an underlying osteochondroma are not always the result of sarcomatous degeneration, and provide support for the theory that cells lining a bursa in a nonphysiologic location can undergo benign neoplasia with subsequent formation of osteochondral bodies.