Surface chondromyxoid fibroma of the distal ulna: unusual tumor, site, and age.

Chondromyxoid fibroma (CMF) is a rare benign cartilage congener tumor comprising less than 1 % of primary bone tumors. Although the age range is wide, it is most commonly seen in the second and third decades. The most frequent location of CMF is in the long tubular bones of the lower extremities, particularly the proximal tibia and distal femur. Although the majority of chondromyxoid fibromas present as intramedullary tumors, a subgroup of chondromyxoid fibromas arising as surface lesions of the bone has recently been described. These are associated with an older mean age and an increased incidence of matrix calcifications. Chondromyxoid fibromas are rare in the distal ulna. We report a CMF presenting as a surface lesion of the distal metaphysis of the left ulna in a 41-year-old woman. We reviewed the literature on chondromyxoid fibromas involving the ulna and found that out of 22 cases, 1 was in the distal ulna, 13 in the proximal ulna, and in the remaining 8 the ulnar sites were unspecified. No case of chondromyxoid fibroma in the published literature had been designated as a surface lesion. Our own unpublished data include 70 chondromyxoid fibromas, 4 of which are in the ulna. Two of these are in the distal portion.

Synovial chondromatosis of the lumbar spine with compressive myelopathy: a case report with review of the literature.

Synovial chondromatosis has been rarely reported to occur in the spine with only one case found in the lumbar spine. We describe another case of synovial chondromatosis in the lumbar spine in a 41-year-old man who presented with compressive myelopathy. The tumor was located in the left ventrolateral corner of the epidural space just below the L(4)-L(5) intervertebral space. Besides being extremely rare, our case was unusual in that the juxtaposed facet joint was radiologically normal.

Ossifying chondroid lipoma.

Chondroid lipoma is a rare variant of lipoma that pathologically can mimic liposarcoma or possibly other sarcomas. Variants of lipoma, including chondroid lipoma, may demonstrate radiological evidence of fat within the tumor, but often display heterogeneous features on imaging studies, making a clinical diagnosis difficult. A large collective experience with the imaging characteristics of chondroid lipoma is lacking due to the rarity of this tumor. We present a case of chondroid lipoma of the upper thigh in a 37-year-old woman who had regions of metaplastic bone formation within the tumor. Radiologically, the tumor presented as a large soft tissue mass with calcification and ossification. Although metaplastic bone formation in conventional lipoma is well described, it has been rarely reported to occur in chondroid lipoma and has not been pathologically documented or illustrated. The imaging findings and histopathology of this unusual tumor are presented, along with a review of the literature.

Giant cell tumor complicating Paget disease of long bone.

Giant cell tumor (GCT) is a rare complication of Paget disease of bone. It usually occurs in the skull or pelvic bones of patients with long-standing polyostotic disease. This report describes a 62-year-old patient who presented with monostotic Paget disease of the distal femur complicated by GCT. He had a 2-year history of discomfort and pain in his left knee. Conventional plain films and MRI demonstrated the characteristic bone changes of Paget disease and an associated lytic lesion involving the epiphyseal and metaphyseal regions of the distal femur. A diagnostic curettage showed the characteristic histopathologic features of Paget disease and GCT. There was no evidence of malignancy. The clinicopathologic features of this rare lesion are described and correlated with a review of the literature.

Primary periosteal lymphoma--rare and unusual.

We describe a primary periosteal lymphoma that involved only the periosteum without affecting the adjacent medulla or the regional lymph nodes. No other lymphomatous foci were found in either the distant lymph nodes or viscera. This unusual presentation simulates the imaging appearance of surface lesions of bone, namely benign and malignant tumors, and departs from the typical appearance of primary lymphoma of bone. Therefore, this rare type of lymphoma should be considered in the differential diagnosis of surface bone lesions.

Atypical extraspinal musculoskeletal tuberculosis in immunocompetent patients, a review. Part I: atypical osteoarticular tuberculosis and tuberculous osteomyelitis.

With the resurgence of pulmonary tuberculosis and musculoskeletal tuberculosis in North America and Europe over the last 20 years, the typical pattern of extraspinal musculoskeletal tuberculosis has been changing; presentation of the disease often mimics that of neoplasia. However, certain radiographic features may offer some clues to the more benign nature of the process and its inflammatory and infectious nature. Although the diagnosis of extraspinal musculoskeletal tuberculosis depends largely on clinical context, it is the radiologist's role to guide the imaging workup to initiate the specific treatment as early as possible. As in classic extraspinal tuberculosis, delayed diagnosis may lead to deformity of the involved joint and permanent disability. This review considers atypical osteoarticular tuberculosis and tuberculous osteomyelitis. We discuss examples of these atypical presentations. All patients were permanent residents in Europe and North America, and all were immunocompetent.

Ultrasound appearance of tendon tears. Part 2: lower extremity and myotendinous tears.

Traumatic tears of the musculotendinous complex at the lower limb are common in clinical practice but can be difficult to detect and to evaluate because of swelling and pain that can limit proper physical examination. They can affect sedentary subjects or active sports participants involved in amateur or professional activities. In the first group tendons are more commonly affected, while myotendinous tears are common in sports players. The aims of this review article are to review the aetiology and pathomechanism of the most common ruptures affecting the tendons and the main myotendinous junctions of the lower extremity and to describe their ultrasound findings as well as to correlate ultrasound appearance with that of the other imaging modalities.

Imaging findings of spontaneous detachment of the deltoid muscle as a complication of massive rotator cuff tear.

A tear at the origin of the deltoid muscle is uncommon and usually occurs as a complication of shoulder surgery. We report a case of spontaneous deltoid detachment as a complication of massive rotator cuff tear in a 70-year-old woman evaluated by standard radiographs, ultrasound, arthrography and MR-arthrography. We present the multimodality imaging findings with review of the literature. We found that ultrasound is an accurate modality in detecting and assessing spontaneous detachment of the deltoid muscle. As ultrasound is a noninvasive, low-cost, and universally available imaging modality we suggest using ultrasound as the first modality for evaluation of spontaneous detachment of the deltoid muscle.

Atypical extraspinal musculoskeletal tuberculosis in immunocompetent patients: part II, tuberculous myositis, tuberculous bursitis, and tuberculous tenosynovites.

Tuberculosis involving the soft tissue from adjacent bone or joint is well recognized. However, primary tuberculous pyomyositis, tuberculous bursitis, and tuberculous tenosynovitis are rare entities constituting 1% of skeletal tuberculosis. Tuberculous tenosynovitis involves most commonly the tendon sheaths of the hand and wrist, and tuberculous bursitis occurs most commonly around the hip. The greater trochanteric bursa and the greater trochanter are the most frequent sites of tuberculous bursitis. Cases of primary tuberculous pyomyositis and tenosynovitis of the tendons of the ankle and foot are seldom reported in the radiology literature. All imaging modalities-plain radiography, bone scan, computed tomography, and magnetic resonance imaging (MRI)--provide information that is helpful in determining therapy. MRI in particular, with its multiplanar capabilities and superb contrast of soft tissue, can demonstrate the extent of the soft tissue mass and access the adjacent bones and joints. However, MRI has no diagnostic specificity in regard to tuberculosis, and in nonendemic areas, biopsy is strongly recommended. All patients in this review were permanent residents of North America or Western Europe and were immunocompetent. Examples of atypical presentations of the above entities are demonstrated.

Ultrasound of tendon tears. Part 1: general considerations and upper extremity.

The role of ultrasound (US) in assessing musculoskeletal disorders is persistently increasing because of its low cost, readiness, noninvasiveness, and possibility of allowing a dynamic examination. Secondary to increased sport practice, tendon tears are more frequently observed in daily medical practice. They deserve early diagnosis to allow proper treatment that can limit functional impairment. The aim of this review article is twofold: to illustrate the US appearance of normal tendons and to describe the US findings of the most common tendon tears.

Focal tuberculous osteomyelitis of the calcaneus secondary to direct extension from an infected retrocalcaneal bursa.

We report a case of focal tuberculous involvement of the posterior margin of the calcaneus with preservation of the articular margin. The route of infection was direct extension through tuberculous retrocalcaneal bursitis, a rare and atypical pathogenesis. Magnetic resonance imaging was helpful in ruling out neoplasm and in limiting the diagnosis to an inflammatory infectious process.

A solitary lesion of talus with mixed sclerotic and lytic changes: Rosai-Dorfman disease of 25 years' duration.

Rosai-Dorfman disease (sinus histiocytosis with massive lymphadenopathy) is an unusual form of histiocytic disorder predominantly affecting children and young adults. Bone lesions are infrequent. We describe a 63-year-old woman with a solitary lesion of the talus which was misdiagnosed for 25 years. The patient never had adenopathy or other organ involvement. The radiographic findings were a mixture of sclerotic and lytic changes, an extremely rare and unusual presentation of the disease.

Solitary cysticercosis of the biceps brachii in a vegetarian: a rare and unusual pseudotumor.

We report a 40-year-old man with cysticercosis presenting as a solitary tumor in the biceps brachii muscle. Physical examination revealed an intramuscular mass and magnetic resonance imaging suggested a cyst. The histologic diagnosis was a cysticercus. Such solitary presentation of muscular cysticercosis is extremely rare with only a handful of sporadic reports in the literature.

Tuberculous pseudotumor of the proximal end of the fibula. A case report.

A 72-year-old asian woman who had immigrated from Vietnam 10 years ago presented with a soft tissue mass around the proximal fibula. Conventional radiographs and magnetic resonance imaging demonstrated a destructive lesion of the head of the fibula with an intact superior tibiofibular joint and an abscess surrounding the destroyed bone. Histopathology obtained by a CT-guided needle biopsy revealed necrotizing epithelioid granulomata without demonstrating acid-fast bacilli. However, culture grew Mycobacterium tuberculosis. When tuberculosis affects the end of a long tubular bone, the adjacent synovial joint is usually involved. Cases where joint involvement does not occur are extremely rare and unusual. We report such a case.

Coexistence of primary bone tumours: report of 4 cases of collision tumours.

OBJECTIVE: To report, in 4 patients, the occurrence of 2 different primary tumours in proximity in the same bone. Three patients had osteosarcomas, and 1 had a giant cell tumour; all had coincident metaphyseal fibrous defect. METHODS: Four patients (2 women, 1 man and 1 boy; 18, 25, 24 and 10 years of age, respectively) presented with progressive pain in the knee and distal thigh. All were studied by radiography, magnetic resonance imaging was done in 3 patients, and diagnostic open biopsy was performed for all. RESULTS: Radiologic studies demonstrated tumours in the distal end of the femur in all 4 patients. Biopsy tissue showed a metaphyseal fibrous defect in all, with coexistence of an associated giant cell tumour in 1 patient and an osteosarcoma in each of the others. In all cases, the metaphyseal fibrous defect was penetrated by the adjacent tumour. CONCLUSIONS: Despite the relative prevalence of metaphyseal fibrous defect, giant cell tumour and osteosarcomas in the distal end of the femur and their occurrence in approximately the same age group, their association has rarely been reported. As both giant cell tumours and osteosarcomas are usually diagnosed late in their clinical course, they may outgrow and destroy any evidence of pre-existing metaphyseal fibrous defect. The rate of destruction is also influenced by the distance between the 2 lesions--the shorter the distance, the earlier the destruction.

True bursal pigmented villonodular synovitis.

We describe two cases of pigmented villonodular synovitis affecting true bursae. This study was also designed to discuss the term "pigmented villonodular bursitis", not confined to true synovial bursae, sometimes creating misunderstanding.