Primary intracranial sarcomas: histopathological features of 19 cases

Primary intracerebral osteosarcoma: a case report

Primary intracerebral sarcomas are rare tumors. Malignant fibrous histiocytoma and fibrosarcoma are the predominant histologies. A 3 year old girl with a primary, intraparenchymal cerebral osteosarcoma, the second case reported in the literature, is described. Partial surgical resection, systemic chemotherapy and radio-surgery has provided tumor control at 18 months. Treatment issues are discussed.

Primary leiomyosarcoma of brain in an adolescent with common variable immunodeficiency syndrome

A 14-year-old girl with common variable immunodeficiency syndrome was found to have a low-grade malignant neoplasm arising in the left temporal lobe of the brain. Ultrastructural and immunohistochemical studies established a diagnosis of leiomyosarcoma, despite the rarity of this tumor in children. In situ hybridization with the EBER probe revealed essentially all of the neoplastic cells to be infected with Epstein-Barr virus (EBV). Children with the acquired immunodeficiency syndrome (AIDS) are known to exhibit an increased incidence of smooth muscle tumors associated with EBV. Similar tumors have been reported in EBV-infected patients undergoing therapeutic immunosuppression. This appears to be the first reported case of childhood leiomyosarcoma where the cause of the underlying immunodeficiency was a genetic rather than acquired disorder. The authors conclude that electron microscopy, immunohistochemistry, and other ancillary techniques are essential in the evaluation of unusual tumors in immunocompromised children, whether the cause is hereditary or acquired.

Low-grade fibromyxoid sarcoma

A low-grade fibromyxoid sarcoma arising in the thigh of a 16-year-old Japanese girl is described. The patient had a well-circumscribed mass measuring 3.5 cm in its greatest diameter within her left vastus medialis muscle and a 6-month history of pain. Microscopically, the tumour was not encapsulated and filtrated into adjacent skeletal muscle. The tumour was characterized by poor to moderate cellularity, a proliferation of bland-appearing spindle tumour cells, and alternating fibrous and myxoid areas with a whorled pattern of the tumour cells. Neither cellular atypia nor mitotic figures were observed. There was no tumour necrosis. Immunohistochemically, the tumour cells were diffusely and strongly positive for vimentin and desmin. Some cells contained alpha smooth muscle actin. They were uniformly negative for CAM5.2, epithelial membrane antigen, muscle-specific actin (HHF35), factor-VIII-related antigen, S-100 protein, neurofilament, CD34, and CD31. The tumour had a diploid DNA content with S-phase fractions of 6.6% by flow cytometry. The patient was alive with no evidence of disease 11 months after excision.

Juvenile fibrosarcoma of the temporal bone

A case of juvenile fibrosarcoma arising from the head and neck region is described. This type of tumour should be considered as a separate entity different from the fibrosarcoma in adults because of the different clinical behaviour. The symptomatology, the radiographic features and the literature data are reviewed.

Primary osteosarcoma of the cerebrum with immunohistochemical and ultrastructural studies: report of a case

A 57-year-old woman with primary intracerebral osteosarcoma is reported. The tumor was identified by computed tomography as a mass with hemorrhage in the right parietal lobe. The surgical and pathological examinations confirmed an osteosarcoma of intracerebral origin. She suffered from repeated local recurrence of the tumor and died about 1 year after the onset. The pathological findings showed features of osteoblastic osteosarcoma with numerous osteoclast-like multinucleated giant cells. Immunohistochemically, tumor cells were positive for vimentin, and partially for actin. Multinucleated giant cells were reactive with vimentin and CD68 antibodies. Ultrastructurally, tumor cells were rich with rough endoplasmic reticulum. These findings are consistent with the histological features of skeletal or extraskeletal osteosarcoma. This is the third case of primary intracerebral osteosarcoma reported in the literature and the first one analyzed ultrastructurally.

Primary intracranial pleomorphic angioleiomyoma--a new morphologic variant. An immunohistochemical and electron microscopic study

BACKGROUND

Angioleiomyomas usually are benign subcutaneous neoplasms that occur most often in extremities of middle-aged individuals. Very few cases have been described in other locations; none along the neuroaxis. An intracranial example of angioleiomyoma displaying unusual morphologic features not seen in the typical peripheral variants of this tumor is described.

METHODS

The tumor was studied with conventional histology, immunohistochemistry with morphometric calculation of proliferation index, immunoelectron microscopy, and DNA flow cytometry.

RESULTS

The tumor was composed of large epithelioid and pleomorphic cells filled with intermediate filaments positive for desmin and vimentin. Scattered cells also expressed myosin and muscle-specific actin. Smooth muscle cell differentiation was confirmed by ultrastructural demonstration of subplasmalemmal dense bodies, attachment plaques, and discontinuous basal lamina. The proliferation index with proliferating cell nuclear antigen (PCNA) monoclonal antibody was 75.78%, whereas it was only 4.22% with Ki67 monoclonal antibodies adopted to paraffin material (MIB-1).

CONCLUSION

The tumor represents a unique morphologic variant of a pleomorphic angioleiomyoma. Cellular pleomorphism and a strong reaction for PCNA in numerous cells suggested that the lesion was malignant. However, the absence of mitotic figures, a small number of Ki-67-positive cells, a diploic DNA pattern, and a low proliferation index in flow cytometry all supported the concept that this neoplasm represented an unusual histologic variant of benign angiogenic leiomyoma. Encapsulation and demarcation of the surgical specimen and the survival of the patient for more than 4 years without recurrence after resection support this interpretation.

Primary leiomyosarcoma of the spinal leptomeninges

A case of leiomyosarcoma of the spinal leptomeninges is presented, with clinical, radiological, light microscopic and immunohistochemical data. The probable origin of the tumor from a pluripotent mesenchymal cell is discussed.

Desmin pathology in neuromuscular diseases

Desmin is an intermediate filament protein that in striated muscle is normally located at Z-bands, beneath the sarcolemma, and prominently at neuromuscular junctions. It is abundant during myogenesis and in regenerating fibers, but decreases in amount with maturation; in regenerating and denervated muscle fibers it is co-expressed with vimentin. Aggregates of desmin occur as nonspecific cytoplasmic bodies or cytoplasmic spheroid complexes, similar to the aggregates of keratin filaments in Mallory bodies or the neurofilament aggregates in Lewy bodies. In all three instances, alpha-B crystallin may be associated with desmin. There are now increasing numbers of neuromuscular disorders in which abnormal amounts of desmin, some abnormally phosphorylated, feature prominently in muscle fibres. Several of these diseases, including spheroid body myopathy, granulo-filamentous body myopathy and the dystrophinopathies, are familial. Ultrastructural and immunohistochemical studies of desmin have considerably broadened our understanding of the pathology of the cytoskeleton in muscle fibers and in certain hereditary neuromuscular diseases.

Intracerebral malignant fibrous histiocytoma: case report and review of the literature

A 50-year-old woman developed an intracerebral malignant fibrous histiocytoma at the site of a previously clipped aneurysm in the right temporal lobe. This tumor rarely originates within the brain. Review of the literature suggests that postoperative and/or postirradiation effects may contribute to the growth of this particular tumor.

Mesenchymal, non-meningothelial tumors of the central nervous system

The spectrum of non-meningothelial mesenchymal tumors that may arise within the central nervous system is presented, based on the current classification of soft tissue tumors. Among malignant types, hemangiopericytoma, rhabdomyosarcoma, mesenchymal chondrosarcoma, and malignant fibrous histiocytoma are the most frequent ones. Rare tumor entities are mentioned. As in soft tissue sarcomas, diagnosis is mainly based on light and electron microscopy, while immunohistochemistry can improve accuracy of diagnosis.