Michael J. Klein

Synovial chondrosarcoma arising in synovial chondromatosis of the right hip

Abstractu2002The 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.

MRI of malignant fibrous histiocytoma of soft tissue: analysis of 13 cases with pathologic correlation

We reviewed the magnetic resonance (MR) appearances of 13 malignant fibrous histiocytomas (MFH) of soft tissue and correlated each with the respective lesions histopathology. The MR images were evaluated for signal intensity on T1- and T2-weighted spin echo sequences, homogeneity of the lesion, presence of internal low signal septations, and margin definition. Histologic subtypes of MFH included storiform-pleomorphic, giant cell, myxoid, and inflammatory. We could not establish a correlation between MR appearance and histopathology. Instead, our series exhibited general features suggestive of malignant soft tissue neoplasms, namely poor margin definition, internal low signal septation, and heterogeneous high signal intensity on T2-weighted images.

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.

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.

Extraosseous extension of Gaucher cell deposits mimicking malignancy.

Two cases are described in which patients with type I Gaucher disease developed extraosseous soft tissue masses consisting of Gaucher cell deposits. In one instance the mass destroyed the posterior cortex of the left distal femur and protruded into the soft tissues. In the second case the lesion involved the proximal tibia and gradually extended into the soft tissues. While the incidence of neoplastic disorder such as lymphoproliferative disease appears to be more common in Gaucher disease patients than in the general population, lesions of benign etiology that mimic these aggressive processes should be considered in the differential diagnosis when cortical destruction with coexisting soft tissue most is found in these patients.

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.

Case report 796

We have presented a young adult with alveolar soft part sarcoma. The lesion occurred in the ankle region and caused extensive bony erosion that mimicked metastasis. At the time of presentation, gingival and subcutaneous metastases were present. Within a short period, however, the patient developed disseminated lung and skeletal metastases as well.

Vertebral arch or posterior spinal tuberculosis

Abstractu2002Posterior 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.

Dedifferentiated parosteal osteosarcoma of the radius

Abstractu2002A 35-year-old woman presented with a painful swelling in the left distal radius that had been present for 1 year. Radiography and computerized tomography revealed a sclerotic surface lesion that had grown over the year and eroded the cortex. Histological examination demonstrated two distinct components: a cartilaginous low- to moderate-grade osteosarcoma on the surface and a high-grade osteosarcoma in the intramedullary component. This case is uncommon in two aspects: the radius is a rare site for such a tumor and the dedifferentiation was revealed at the time of the first surgery and was not secondary to recurrence.

Case report 795

We described a case of high-grade surface sarcoma of the radius in a 14-year-old boy. The lesion appeared radiologically benign and was confined to the surface. The tumor was resected. At the time of biopsy both lungs showed diffuse metastases. Following surgery the patient underwent chemotherapy and the lung metastases improved. The pertinent literature was briefly discussed.