Percutaneous Ethibloc injection in aneurysmal bone cysts

Objective. To investigate whether the injection of Ethibloc into aneurysmal bone cysts can be an effective treatment modality. Design and patients.Ethibloc is an alcoholic solution of zein (corn protein) which has thrombogenic and fibrogenic properties. Ten patients with aneurysmal bone cysts were treated with CT-guided percutaneous injection of Ethibloc into the cyst cavity. Ethibloc injection was the primary treatment in five patients. Four patients had recurrence following previous curettage and bone grafting and one patient had not responded to injection into the lesion of autologous iliac crest bone marrow aspirate. Three patients needed a second injection. The median follow-up was 27 (6–60) months. Results and conclusion.Symptoms were relieved in all patients. At imaging, seven patients had resolution of the lesion and three had partial response at the most recent follow-up. Complications consisted of a local transitory inflammatory reaction in two patients and an aseptic abscess in one patient. This relatively simple, minimally invasive procedure makes an operation unnecessary by stopping the expansion of the cyst and inducing endosteal new bone formation. This technique may be used as the primary management of aneurysmal bone cysts excluding spinal lesions. Received: 19 July 1999 Revision requested: 20 September 1999 Revision received: 9 November 1999 Accepted: 6 December 1999     

Solitary infantile myofibromatosis involving the clavicle

A rare case of solitary infantile myofibromatosis of bone is reported in the right clavicle of a 15-year-old boy. A radiograph demonstrated an osteolytic lesion with a sharp margin and a sclerotic rim. CT revealed a circumscribed lesion with slight expansion of the cortex. On MRI the lesion appeared isointense to muscle on T1-weighted images, bright on T2-weighted images, and showed marked gadolinium enhancement. The patient was well, without evidence of recurrence or metastasis, 4 years and 5 months following resection. Received: 11 August 1998 Revision requested: 5 October 1998, 18 March 1999 Revision received: 15 March 1999, 23 April 1999 Accepted: 28 April 1999     

Cystic fibrous dysplasia mimicking giant cell tumor: MRI appearance

We report the case of a 43-year-old man who presented with an osteolytic and expansive lesion in the left distal femur mimicking a giant cell tumor. Magnetic resonance imaging (MRI) showed that most of the lesion was cystic, and histological examination revealed fibrous dysplasia with marked cystic degeneration. Radiographic findings of cystic fibrous dysplasia in the end of a long bone may be similar to those of a giant cell tumor, and a biopsy is essential for the final diagnosis. Received: 4 June 1999 Revision requested: 10 August 1999 Revision received: 13 September 1999 Accepted: 15 September 1999     

Hemangioma of bone arising in the ulna: imaging findings with emphasis on MR

An 18-year-old woman presented with left elbow joint pain. Radiographs and computed tomographic scan showed a well-defined osteolytic lesion of the left ulna associated with a honeycomb appearance on the radiographs. Magnetic resonance images showed intermediate signal intensity on T1-weighted images and mixed intermediate and high signal intensities on T2-weighted images. Only the periphery of the lesion enhanced with intravenously injected gadolinium-diethylenetriamine pentaacetic acid. The lesion was curetted to avoid pathologic fracture, and a histologic diagnosis of cavernous hemangioma of bone was made. Hemangioma involving the ulna is rare, but should be included in the differential diagnosis of a radiographic osteolytic lesion with a honeycomb appearance. Received: 17 September 1999 Revision requested: 31 October 1999 Revision received: 10 December 1999 Accepted: 13 December 1999     

Hyperfunctioning parathyroid carcinoma

Primary hyperparathyroidism is rarely caused by carcinoma. We report a patient who manifested many of the clinical and radiographic features of the disease. When encountering symptomatic hypercalcemia with or without a palpable neck mass, carcinoma should be considered in the differential diagnosis. Patient survival depends on an aggressive surgical approach to the primary lesion and recurrent disease. Received: 27 May 1999 Revision requested: 28 June 1999 Revision received: 22 September 1999 Accepted: 27 September 1999     

Extraskeletal osteosarcoma arising in myositis ossificans

A 53-year-old woman had extraskeletal osteosarcoma that developed from a soft tissue bony mass present on the volar aspect of the left wrist for 4 years. Initially, the bony mass was soft and movable, but during the first year it became hard and fixed. The patient had no history of trauma. Because the lesion did not grow or cause any symptoms, the patient did not come to the hospital until 4 years after she first noticed the lesion. Radiologically, the bony mass had features characteristic of mature myositis ossificans, showing ”eggshell” ossification. A nonmineralized soft tissue mass occurred between the surface of the radius and the bony shell. Histologically, a high-grade osteosarcoma was present between the surface of the radius and the well-differentiated bone tissue, which included fatty and hematopoietic marrow. All the findings indicated that our patient had an extremely rare case of malignant transformation of myositis ossificans. Received: 22 June 2000 Revision requested: 2 August 2000 Revision received: 14 September 2000 Accepted: 25 September 2000     

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     

Metadiaphyseal chondroblastoma of the thumb

Chondroblastoma is typically located in the epiphysis. Predominant metadiaphyseal location is very rare, as is involvement of the digits. We describe a case of chondroblastoma involving the metadiaphysis of the thumb. The patient was a 13-year-old boy who presented with pain and swelling of his left thumb. Radiographs showed an expanded lytic lesion involving the whole metaphysis and diaphysis of the proximal phalanx, which subsequently progressed to involve the epiphysis. Curettage and bone grafting were done. Received: 9 July 1999 Revision requested: 12 August 1999 Revision received: 1 November 1999 Accepted: 4 November 1999     

MR imaging of inflammatory joint diseases of the foot and ankle

Pain affecting the foot and ankle is a common complaint frequently attributable to inflammatory joint diseases. Although conventional radiography is regarded as the initial step in the diagnostic investigation, MR imaging may contribute to further evaluation of these patients due to the direct visualization of the inflammatory soft tissue formed in the disease and its effects on bone, cartilage and para-articular structures. The high spatial resolution of MR imaging combined with tissue characterization often allows initial detection of inflammatory joint abnormalities at a stage that precedes radiographic evaluation. The typical MR appearance of certain inflammatory joint disorders may be helpful in narrowing the wide differential diagnosis. Furthermore, MR imaging can be used for an exact assessment of the extent of the disorder as well as its complications. Accurate diagnostic information can guide the clinician in further diagnostic tests and implementation of proper therapeutic treatment. Received: 12 November 1998 Revision requested: 12 February, 10 June 1999 Revision received: 14 September 1999 Accepted: 20 September 1999     

Proliferative myositis in a child

A case of proliferative myositis in the lumbar paraspinal muscles in a 14-year-old boy is presented. Imaging investigations including plain radiograph, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), bone scan and positron emission tomography (PET) were suggestive of an inflammatory process such as myositis ossificans. The diagnosis was made by incisional biopsy. More pronounced edema, more muscle fiber necrosis and a higher cellularity were found compared to adult cases. The karyotype of the lesion was normal. Clinically, the mass disappeared spontaneously. After 24 months, asymptomatic bridging ossification between the third and fourth lumbar vertebrae was noted. Received: 18 February 1999 Revision requested: 29 March 1999 Revision received: 23 August 1999 Accepted: 24 August 1999     

Chondromyxoid fibroma of the acromium with soft tissue extension

Chondromyxoid fibroma is an unusual, benign tumor of cartilaginous origin and represents less than 1% of all primary bone tumors. It usually involves the long bones around the knee joint or the flat bones of the pelvis or ribs. Soft tissue extension is also thought to be rare in these lesions. They are usually eccentrically located in the metaphyses of the long bones and centrally in the flat bones. The radiographic appearances are characteristically those of a single, lytic lesion with lobulated margins, septations, cortical expansion and a sclerotic rim. Histologically, they display a lobulated pattern with spindle-shaped cells lying within a myxoid matrix with areas of hyaline cartilage. The differential diagnosis includes giant cell tumor, chondroblastoma or enchondroma as well as chondrosarcoma. The rarity of these lesions may render the diagnosis difficult to make, especially when the lesion involves an unusual site such as the acromium. Received: 21 June 1999 Revision requested: 27 September 1999 Revision received: 27 October 1999 Accepted: 28 October 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     

Intraosseous schwannoma of the metacarpal

Intraosseous schwannoma (neurilemmoma) is an extremely rare, benign neoplasm, constituting less than 0.2% of primary bone tumors. It infrequently involves the bones of the hand. We present a case of intraosseous neurilemmoma of the metacarpal. Received: 26 July 1999 Revision requested: 16 August 1999 Revision received: 16 September 1999 Accepted: 4 October 1999     

Immunoglobulin D myeloma presenting as an extraosseous soft tissue tumor

We report a 69-year-old man who suffered an extraosseous tumor of immunoglobulin D myeloma (lambda type) in the shoulder girdle, mimicking a primary soft tissue sarcoma. The tumor was isointense with adjacent muscle on T1-weighted MR images, and hyperintense on T2-weighted images. No continuity with the neighboring bone was noted. After administration of gadolinium, the central part of the tumor showed marked contrast enhancement. Although the tumor showed a complete response to the initial chemotherapy, the patient died of the disease 31 months after its initial manifestation. Several bone marrow aspirations and biopsies of the ilium and sternum had shown no increase in plasma cells (range 0.6–1.2%) until the disease became advanced 19 months after its initial manifestation. Received: 1 September 2000 Revision requested: 9 October 2000 Revision received: 11 November 2000 Accepted: 15 November 2000     

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     

Clear cell chondrosarcoma of the pelvis in a skeletally immature patient

We report on a case of clear cell chondrosarcoma (CCCS) of the left iliac bone in a 12-year-old skeletally immature boy. Radiographic examination revealed an aggressive osteolytic lesion with areas of mineralization. Fluid-fluid levels were seen on T2-weighted MR images. Laboratory data showed slight elevation of serum alkaline phosphatase. The biopsy specimen showed histological features of CCCS with some resemblance to osteosarcoma, such as prominent irregular osteoid formation among clear tumor cells. Surgical treatment was accomplished without pre- or post-operative chemotherapy. Because of the patient’s age, elevated serum alkaline phosphatase, and histopathology with prominent osteoid production, this case could be confused with osteosarcoma. Although CCCS is an extremely rare bone tumor in children, it is important to be aware that it may arise in a skeletally immature patient. CCCS, unlike osteosarcoma, is not treated with neo-adjuvant chemotherapy. Received: 13 November 1998 Revision requested: 28 December 1998 Revision received: 11 January 1999 Accepted: 14 January 1999     

MRI in decompression illness

We report a case of decompression illness in which the patient developed paraparesis during scuba diving after rapid ascent. MRI of the spine revealed a focal intramedullary lesion consistent with the symptoms. The pathophysiological and radiological aspects of spinal decompression illness are discussed. Received: 2 July 1999/Accepted: 3 September 1999     

Malignant chondroblastoma presenting as a recurrent pelvic tumor with DNA aneuploidy and p53 mutation as supportive evidence of malignancy

We report a rare case of malignant chondroblastoma, which presented in a 47-year-old man as a recurrent tumor, 18 years following wide excision of a typical pelvic chondroblastoma. Radiologic studies of the recurrent tumor showed a large, lytic, destructive lesion of the right pelvic bones and femur, with a pathologic fracture of the latter, a large pelvic soft tissue mass, and multiple pulmonary metastases. Biopsy tissue showed typical features of chondroblastoma, but also increased nuclear atypia, hyperchromasia, and pleomorphism, compared to the original tumor, and, most significantly, abnormal mitotic figures. Immunohistochemical studies of the recurrent tumor revealed p53 mutation and extensive proliferative activity, and flow cytometric studies showed DNA aneuploidy, none of which was present in the original tumor. The patient received chemotherapy and radiation, but died of disease eight months after presentation. We also review chondroblastoma in general, to assign this unusual lesion to a tumor subtype. Received: 29 March 1999 Revision requested: 27 April 1999 Revision received: 23 June 1999 Accepted: 29 June 1999     

Erdheim-Chester disease with intramuscular lipogranuloma

We report on a rare manifestation of Erdheim-Chester disease with intramuscular lipogranuloma. The patient was a 66-year-old man who noted a soft tissue mass in the right quadriceps femoris muscle. Radiographs revealed symmetrical osteosclerosis in the diametaphysis of both femora and tibiae. An open biopsy revealed a proliferation of lipid-laden histiocytes in the femoral bone marrow and the quadriceps femoris muscle. To our knowledge, this is the second case of Erdheim-Chester disease involving muscle. Received: 4 October 1999 Revision requested: 18 November 1999 Revision received: 1 December 1999 Accepted: 2 December 1999     

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