Neurilemmoma of the mandible

Intraosseous neurilemmoma is rare, representing less than 1% of benign primary bone tumors. The site most commonly involved is the mandible. We report on a neurilemmoma of the mandible in a 30-year-old woman. A panoramic radiograph of the mandible showed a well-defined unilocular osteolytic lesion with a thin uniform sclerotic margin located in the body of the mandible. The CT scan confirmed a well-defined osteolytic lesion with thinning of the cortex of the body of the left side of the mandible. Histologically, the lesion was a moderately cellular neoplasm with distinct palisading and numerous Verocay bodies. Ultrastructurally, the cytoplasmic membranes were distinct and coated by amorphous bands of basal lamina. Complete excision was achieved by removing the tumor from the inferior alveolar nerve. Received: 26 February 1999 Revision requested: 29 March 1999 Revision received: 12 April 1999 Accepted: 13 April 1999     

Giant ancient schwannoma of the pelvis

A 43-year-old man with a large ancient schwannoma of the pelvis, presenting with varicose veins, is reported. Ancient schwannoma (neurilemmoma) is a benign tumour of nerve sheath origin characterised histologically by features of severe degeneration and which rarely can grow to a large size. Malignant transformation, though reported, is extremely rare. Received: 17 September 1999 Revision requested: 13 October 1999 Revision received: 22 June 2000 Accepted: 28 June 2000     

Osteosarcoma of the metatarsal bone

A case of osteosarcoma arising from a metatarsal bone is reported, focusing on the radiological findings and differential diagnosis. Received: 16 November 1998 Revision requested: 17 December 1998 Revision received: 11 January 1999 Accepted: 14 January 1999     

Chronic ulceration of the leg following extensive scarring due to a snake bite complicated by squamous cell carcinoma

Chronic ulcers of the leg are common in Brazil, perhaps more common than in the developed world. We report a case of a chronic ulcer of the leg following extensive scarring due to a bite by a venomous snake, which eventually led to a squamous cell carcinoma. Received: 16 August 1999 Revision requested: 8 October 1999 Revision received: 10 December 1999 Accepted: 15 December 1999     

Elastofibroma of the neck

Elastofibromas are benign lesions of the chest wall. We describe the first reported case of elastofibroma in the neck. Imaging features as well as location of the lesion were atypical. On computed tomography and magnetic resonance imaging the lesion contained a marked preponderance of fat, because the lesion arose within fat. Received: 12 November 1998 Revision requested: 18 November 1998 Revision received: 16 August 1999 Accepted: 24 August 1999     

MRI-induced retrocalcaneal bursitis

This case report describes a patient with acute retrocalcaneal bursitis, which developed after MRI examination of the ankle. The sagittal T2*-weighted gradient echo sequence revealed an extensive susceptibility artifact in the area surrounding the Achilles tendon near its insertion at the os calcis. This artifact was caused by postsurgical metallic particles. We postulate that these particles were mechanically stimulated by the magnetic field and induced the inflammatory response. Received: 20 July 1998 Revision requested: 14 September 1998, 16 March 1999 Revision received: 15 February 1999, 20 May 1999 Accepted: 21 May 1999     

Deep soft tissue leiomyoma of the thigh

A case of ossified leiomyoma of the deep soft tissues of the left thigh is presented. The radiographic appearance suggested a low-grade chondrosarcoma. MRI of the lesion showed signal characteristics similar to muscle on both T1- and T2-weighted spin echo sequences with linear areas of high signal intensity on T1-weighted images consistent with medullary fat in metaplastic bone. Histopathological examination of the resected specimen revealed a benign ossified soft tissue leiomyoma. Received: 23 December 1998 Revision requested: 31 January 1999 Revision received: 11 March 1999 Accepted: 16 March 1999     

Fibroma of tendon sheath of the infrapatellar fat pad

We report on a 13-year-old boy who was found to have a fibroma of the tendon sheath associated with the patellar tendon and within Hoffa’s fat pad of the knee. This benign tumor has never been described in this location previously. The MRI characteristics are correlated with the histologic findings. Received: 20 November 1998 Revision requested: 17 December 1998 Revision received: 16 February 1999 Accepted: 19 February 1999     

Recurrent, multiple, calcified soft tissue metastases from osteogenic sarcoma without pulmonary involvement

Osteosarcoma (osteogenic sarcoma) metastasizes primarily to the lung. With the introduction of neoadjuvant chemotherapy as part of the treatment, the overall and disease-free survival rates have dramatically improved. In this case report, a young man with multiple soft tissue and bone metastases, including a rare large bone-forming retroperitoneal metastasis, is described. Despite the extensive extrapulmonary metastases, the patient did not develop pulmonary metastases in the 4 years following initial presentation of the primary tumour. Received: 16 December 1998 Revision requested: 14 January 1999 Revision received: 30 July 1999 Accepted: 1 August 1999     

Synovial desmoplastic fibroblastoma of hip joint with bone erosion

A 78-year-old woman presented with pain at the left hip. Initial radiographs showed minimal age-related changes. Over the next 2 years she developed large erosions in the left femoral neck and proceeded to hip replacement. Histological examination showed bland spindle cells in a loose and hyalinised collagenous stroma considered to represent a desmoplastic fibroblastoma (collagenous fibroma). This is the first reported case of synovial desmoplastic fibroblastoma. Received: 23 November 1998 Revision requested: 16 December 1998 Revision received: 10 February 1999 Accepted: 4 March 1999     

Castleman disease: CT and MR imaging features of a retroperitoneal location in association with paraneoplastic pemphigus

We describe the CT and MRI features of a case of Castleman disease which was unusual by both its retroperitoneal location and its association with paraneoplastic pemphigus. Received: 9 July 1998; Revision received: 16 November 1998; Accepted: 12 January 1999     

Hypertrophic osteoarthropathy of one leg – a sign of aortic graft infection

We report a rare case of hypertrophic osteoarthropathy (HOA) confined to the right leg secondary to aortic graft infection. The development of HOA exclusively localized to areas distal to a vascular prosthesis may be the presenting manifestation of graft infection and a crucial diagnostic clue in the early detection of vascular graft infection. HOA is diagnosed by its characteristic radiographic and scintigraphic pattern. Most prosthetic, especially aortic, graft infections are uniformly fatal if not treated by aggressive surgical and antibiotic therapy. Recognition of this uncommon association may facilitate an early diagnosis, which usually requires immediate surgical therapy. Received: 16 November 1998 Revision requested: 17 December 1998 Revision received: 11 January 1999 Accepted: 14 January 1999     

Myxoma of the humerus: an exceptional site of origin

Myxoma of bone, outside of the jaws, is exceptional. We present such a tumor in the humerus and discuss the criteria for the diagnosis of myxoma. Received: 10 August 1999 Revision requested: 10 September 1999 Revision received: 14 September 1999 Accepted: 14 September 1999     

Secondary involvement of breast with non-Hodgkin's lymphoma in a paediatric patient presenting as bilateral breast masses

We report a paediatric case of non-Hodgkin's lymphoma with secondary breast involvement. On US exam there were bilateral multiple well-defined masses. Contrast-enhanced thorax CT demonstrated the breast lesions as well as enhancing masses. To our knowledge, this type of lymphomatous breast involvement in a child is rare and its CT features are very rarely demonstrated. Received: 16 October 1998; Revision received: 21 April 1999; Accepted: 28 May 1999     

MR appearances in a case of femoral ecchinococcosis

Magnetic resonance (MR) findings of a rare case of osseous echinococcosis with involvement of the femur are described. Attention is drawn to the typical MR appearances and therapeutic management. Received: 4 October 1999 Revision requested: 28 October 1999 Revision received: 20 November 1999 Accepted: 1 December 1999     

Giant distal humeral geode

We describe the imaging features of a giant geode of the distal humerus in a patient with rheumatoid arthritis, which presented initially as a pathological fracture. The value of magnetic resonance imaging in establishing this diagnosis is emphasized. Received: 8 July 1999 Revision requested: 24 August 1999 Revision received: 25 October 1999 Accepted: 26 October 1999     

Premature epiphyseal fusion and degenerative arthritis in chronic recurrent multifocal osteomyelitis

A 9-year-old boy was diagnosed with chronic recurrent multifocal osteomyelitis affecting multiple sites. During an 8-year follow-up he developed premature closure of a distal radial epiphysis and degenerative changes in the adjacent radiocarpal joint. Received: 26 July 1999 Revision requested: 24 August 1999 Revision received: 27 September 1999 Accepted: 8 October 1999     

Glenohumeral instability: evaluation using MR arthrography of the shoulder

In the setting of glenohumeral instability or when internal derangement of the shoulder joint is suspected, MR arthrography has been demonstrated to be an accurate diagnostic imaging technique. Knowledge of the complex anatomy of the shoulder and its variations is essential in order to maximize diagnostic accuracy. Received: 24 February 1999 Revision requested: 19 April 1999 Revision received: 12 May 1999 Accepted: 13 May 1999     

Intra-articular regional migratory osteoporosis of the knee

We report a case of lntra-articular regional migratory osteoporosis of the knee in a 53-year-old man. The case demonstrates an unusual pattern of migration of the marrow edema within the knee joint. This phenomenon has received scant attention in the radiological literature. Received: 9 July 1999 Revision requested: 24 August 1999 Revision received: 6 October 1999 Accepted: 8 October 1999     

Extraosseous calcified plasmacytoma causing thoracic myelopathy

We report on a rare, calcified, plasma cell tumor of the spine causing progressive myelopathy. Other unusual features were the lack of an osseous lesion at the site of the mass, considerable calcified amyloid within the mass but no identifiable amyloid elsewhere, and normal serum immunoelectrophoresis. Received: 12 February 1999 Revision requested: 18 March 1999 Revision received: 19 April 1999 Accepted: 20 April 1999