Ibrahim Fikry Abdelwahab

Synovial chondrosarcoma arising in synovial chondromatosis of the right hip

Abstract The case of a 55-year-old man with chondrosarcoma to the cervical spine is described. Two years previously the patient had undergone a right hip replacement for synovial chondromatosis. Re-evaluation of the biopsy specimen from the right hip taken at the time of the initial operation showed areas of chondrosarcoma arising in the background of synovial chondromatosis. The unusual presentation of this rare entity is discussed.

Transarticular invasion of joints by bone tumors: hypothesis.

Eight bone tumors with associated transarticular invasion of the sacroiliac joints are described. All invaded the true synovial joint and spread to the opposing bone. One tumor was benign, and the other seven were malignant. Five of the seven were primary and two were metastatic cancer. One, a myeloma, invaded the disc spaces between the fourth and fifth lumbar vertebrae and the fifth lumbar vertebra and sacrum as well as the sacroiliac joint. The right facet joints of the two vertebrae were also invaded. After a thorough search of the literature, we find that the sacroiliac joint is the most common joint to be invaded by tumors. This is followed by the vertebral disc spaces and, last, the facet joints. Apart from these joints, we were unable to find any radiographic documentation of other joints being transarticularly invaded by tumors. We noted that there is a direct relation between transarticular tumor spread and joints that lack mobility and that certain tumors, benign and malignant, tend to invade these joints.

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.

Intramuscular ganglia arising from the superior tibiofibular joint: CT and MR evaluation.

ObjectiveTo evaluate the role of magnetic resonance imaging (MRI) and computed tomography (CT) in the diagnosis of intramuscular ganglia (IMG) that arise from the superior tibiofibular joint (STFJ).Material and MethodsOur series consisted of three men and three women. Four patients were studied by MRI, one by CT only, and two by both modalities. Contrast was used in one of the two patients studied by CT. MRI was obtained in at least two orthogonal planes to demonstrate the relation of the ganglia to STFJ.ResultsThe MR and CT appearance of these ganglia was basically that of a well-defined soft tissue mass with low attenuation on CT images consistent with the presence of fluid. On MR studies, they had an isointense signal on T1-weighted images and a homogenous high-intensity signal on T2-weighted images. MRI demonstrated the attachment of these ganglia to the STFJ.ConclusionCT and MRI were effective, noninvasive modalities in the evaluation of IMG. The imaging features on both modalities were consistent with the presence of fluid-containing lesions that had close proximity and were attached to the STFJ. The combination of location and the fluid consistency of these lesions facilitated the diagnosis.

Case report: Angiosarcoma occurring in a bone infarct

An unusual case of an angiosarcoma that occurred in a bone infarct is presented. A bone infarct may occasionally dedifferentiate to an osteogenic sarcoma or a malignant fibrous histocytoma. However, the association of angiosarcoma with a bone infarct is extremely rare. To the best of our knowledge, there is only one other report of this association in the English literature.

Fibromyxoma of bone

We report two cases of fibromyxoma, one affecting the iliac crest and the second involving the proximal shaft of the tibia. Fibromyxoma is a rare neoplasm related to benign fibrous tumors and is characterized by exuberant, extracellular, ground substance production. Its histologic appearance is benign and distinctive and can be readily distinguished from that of myxoid chondrosarcoma or chondromyxoid fibroma. The radiographic picture is, however, difficult to interpret, and the entity can be easily mistaken for other tumors.

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.

Vertebral arch or posterior spinal tuberculosis

Abstract Posterior spinal tuberculosis or arch tuberculosis is a form of skeletal tuberculosis that selectively involves the vertebral arch. It may mimic skeletal neoplasm clinically and radiographically. Although posterior spinal tuberculosis has been reported in developing countries it has rarely been found in the United States. As a result, there is limited information about this entity in the US literature. We are presenting our experience in a patient born in the United States.

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 L4–L5 intervertebral space. Besides being extremely rare, our case was unusual in that the juxtaposed facet joint was radiologically normal.

Case report 794

A rare case of primary leiomyosarcoma of the proximal end of the shaft of the right femur in a 52-year-old man has been reported. Proof was obtained by an open biopsy. The origin, pathological features, and clinical presentation have been discussed. The radiographic appearance, the differential diagnosis, and the poor prognosis of this tumor have also been indicated.