Tumors and diseases of the joint.

A variety of different diseases affect the synovium, including infection, noninfectious immunologic inflammatory conditions, degenerative arthroses, crystal deposits, trauma, and tumors. Tumors of the synovium are relatively uncommon. Any mesenchymal tumor may arise in the synovium, but most recapitulate its normal counterpart including synoviocytes, blood vessels, fat, and fibrous tissue.

Low-grade fibromyxoid sarcoma of the perineum with heterotopic ossification: case report and review of the literature.

Low-grade fibromyxoid sarcoma was first described more than 20 years ago. Subsequently, it was discovered to carry the recurrent chromosomal translocation t(7;16)(q33;p11) encoding a FUS-CREB3L2 fusion oncoprotein. Molecular tests for this pathognomonic gene fusion can confirm the identity of histologic variants (such as hyalinizing spindle cell tumor with giant rosettes) and suggest that some cases of sclerosing epithelioid fibrosarcoma may represent a high-grade version of this entity.

Duodenal epithelioid gastrointestinal stromal tumor with prominent granular cell features.

Gastrointestinal stromal tumors are a group of mesenchymal tumors arising from the wall of the gastrointestinal tract that are characterized by activating mutations in KIT or PDGFRA. Their proper recognition is important clinically because of their potential responsiveness to targeted therapies. We report a case of duodenal gastrointestinal stromal tumor with a highly unusual epithelioid morphology that had an appearance reminiscent of a steroid producing neoplasm, such as an adrenal cortical neoplasm or, alternatively, a renal cell carcinoma variant.

Epithelioid hemangioma of bone revisited: a study of 50 cases.

The clinical and pathologic features of 50 epithelioid hemangiomas of bone are analyzed. There were 29 males and 21 females who ranged in age from 10 to 75 (mean 35) years. The tumors arose in long tubular bones (40%), short tubular bones of the distal lower extremity (18%), flat bones (18%), vertebrae (16%), and small bones of the hands (8%).

Translocation and expression of CSF1 in pigmented villonodular synovitis, tenosynovial giant cell tumor, rheumatoid arthritis and other reactive synovitides.

We recently demonstrated that CSF1, the ligand of the tyrosine kinase receptor, CSF1R, can be translocated in pigmented villonodular synovitis (PVNS) and tenosynovial giant cell tumor (TGCT). In this study, we evaluated the staining characteristics of PVNS/TGCT and reactive synovitides for CSF1 and CSF1R by in situ hybridization and immunohistochemistry on tissue microarrays and correlated these findings with the recently described translocation. We collected specimens of TGCT/PVNS from 60 patients and of rheumatoid arthritis and other reactive synovitides from 74 patients.

Calcific myonecrosis: keys to recognition and management.

Objective: Calcific myonecrosis masses can become quite large and worrisome for malignancy. The key to recognition is a combination of radiologic imaging features and remote clinical history of injury associated with compartment syndrome or vascular or neurologic compromise.

Conclusion: This article will highlight importance of correct diagnosis by identifying the severe and devastating complications following inappropriate management.

Ligation and partial excision of the cauda equina as part of a wide resection of vertebral osteosarcoma: a case report and description of surgical technique.

Study Design: A case report.

Objectives: To describe the unique challenges and novel surgical approach to treatment of vertebral osteosarcoma involving the dura as a margin.

Summary Of Background Data: Osteosarcoma of the vertebral column is a rare, malignant osseous tumor, carrying a poor prognosis.

Primary bone tumors of the orbit.

Primary tumors of orbital bone constitute 0.6% to 2% of all orbital tumors. Our experience over a 24-year period in the Orbital Clinic at the University of British Columbia yielded 62 (1.

Most osteomalacia-associated mesenchymal tumors are a single histopathologic entity: an analysis of 32 cases and a comprehensive review of the literature.

Oncogenic osteomalacia (OO) is a rare paraneoplastic syndrome of osteomalacia due to phosphate wasting. The phosphaturic mesenchymal tumor (mixed connective tissue variant) (PMTMCT) is an extremely rare, distinctive tumor that is frequently associated with OO. Despite its association with OO, many PMTMCTs go unrecognized because they are erroneously diagnosed as other mesenchymal tumors.

Tissue microarray validation of epidermal growth factor receptor and SALL2 in synovial sarcoma with comparison to tumors of similar histology.

Histological diagnosis of synovial sarcoma can be difficult. Genome-wide expression profiling has identified a number of genes expressed at higher levels in synovial sarcoma than in other soft tissue tumors, representing excellent candidates for diagnostic immunohistochemical markers. A tissue microarray comprising 77 sarcomas, including 46 synovial sarcomas, was constructed to validate identified markers and investigate their expression in tumors in the differential diagnosis of synovial sarcoma.

Collagen-rich tumors of soft tissues: an overview.

Although relatively common, soft tissue tumors frequently present diagnostic problems for practicing pathologists. Immunohistochemistry has facilitated the diagnosis of many mesenchymal tumors; however, there is considerable overlap in the staining profiles among cells demonstrating fibroblastic and myofibroblastic differentiation. It has been our experience that soft tissue tumors associated with abundant extracellular collagen deposition commonly cause problems in classification.

Fibroid in the buttock: an unexpected diagnosis.

Uterine leiomyomas (fibroids) are very common lesions with well-described imaging features. We present an unusual case of a fibroid which presented in the buttock with atypical clinical and imaging features in a woman who had had a previous hysterectomy. Despite extensive imaging and biopsies, the diagnosis was not suspected until pathological evaluation of the resected mass.

Epithelioid angiosarcoma of the bone: a series of 10 cases.

The clinical and pathologic features of 10 epithelioid angiosarcomas of bone were analyzed. There were eight males and two females who ranged in age from 26 to 83 years (mean 62 years). Four tumors were solitary and six were multifocal.

Novel fluorescent ligase detection reaction and flow cytometric analysis of SYT-SSX fusions in synovial sarcoma.

Synovial sarcomas (SS) are characterized by the t(X;18)(p11;q11) translocation and its resultant fusion gene, SYT-SSX. Two homologues of the SSX gene (ie, SSX1 and SSX2) are involved in the vast majority of SS and the SYT-SSX1 type of fusion has been associated with inferior clinical outcome. Thus, detection of the presence and type of SYT-SSX fusion is critical for diagnosis and prognosis in SS.

Pathogenesis of orbital cholesterol granuloma.

Two cases are presented of orbital cholesterol granuloma associated with gradual proptosis arising in men aged 35 and 41 years. Computed tomography demonstrated osteo-lytic masses in the frontal bone at the lacrimal fossa. Curettage revealed a characteristic histology of foreign body reactions surrounding cholesterol clefts.

Coamplification of 12p11 and 12q13 approximately q22 in multiple ring chromosomes in a spindle cell sarcoma resolved by novel multicolor fluorescence in situ hybridization analysis.

An 80-year-old male presented with a lobulated mass in the lower abdominal wall. A diagnosis of an intermediate grade myofibroblastic spindle cell sarcoma was made. Cytogenetic analysis demonstrated a complex karyotype with a der(6), a small marker and five, different in size, ring chromosomes.

Cryptic t(X;18), ins(6;18), and SYT-SSX2 gene fusion in a case of intraneural monophasic synovial sarcoma.

A 54-year-old male presented with a spontaneous peroneal nerve palsy and a diagnosis of monophasic synovial sarcoma (SS) was rendered by histologic examination. Cytogenetic analysis revealed a complex abnormal karyotype without evidence of the typical t(X;18)(p11;q11) associated with SS. Subsequent reverse transcriptase polymerase chain reaction analysis showed the presence of an SYT/SSX2 fusion transcript, confirming the presence of a cyptic t(X;18).

Ollier's disease in association with adjacent fibromatosis.

Ollier's disease (enchondromatosis) is a nonhereditary disorder of mesodermal dysplasia. It is characterized by the presence of multiple enchondromas that typically affect the metaphyseal ends of bones. The association of Ollier's disease with adjacent fibromatosis has, to our knowledge, not been previously described.

Molecular characterisation of soft tissue tumours: a gene expression study.

Background: Soft-tissue tumours are derived from mesenchymal cells such as fibroblasts, muscle cells, or adipocytes, but for many such tumours the histogenesis is controversial. We aimed to start molecular characterisation of these rare neoplasms and to do a genome-wide search for new diagnostic markers.

Methods: We analysed gene-expression patterns of 41 soft-tissue tumours with spotted cDNA microarrays.

Dermatofibrosarcoma protuberans: MR imaging features.

Objective: The objective of our study was to describe the MR imaging features of 10 cases of histologically confirmed dermatofibrosarcoma protuberans.

Conclusion: MR imaging is useful in identifying the extent and location of dermatofibrosarcoma protuberans. Although most cases of this tumor are superficial and well defined, we have shown three cases in which the tumor was in a deep location and one case in which the tumor was ill defined in appearance.