Pigmented villonodular synovitis of the foot and ankle: a review of six cases.

Pigmented villonodular synovitis is a rare but well recognized proliferative lesion of synovial tissue. It has been most commonly described in the knee and hip, with most series reporting <5% occurrence in the foot and ankle. Six patients with pigmented villonodular synovitis of the foot and ankle that was treated between 1978 and 1997 were reviewed. Four of the patients had not been previously diagnosed, and two patients presented with recurrent disease. All six were women. Two patients' disease presented isolated to the ankle joint. The other four involved more than one joint: subtalar joint and midfoot in two, and the metatarsal region in two. The histology of the primary and recurrent lesions did not differ. The recurrent lesions were more diffuse and locally destructive. Five were found on magnetic resonance imaging to be a low-to-medium signal intensity mass on T1- and T2-weighted images. Surgical management ranged from simple excision to synovectomy to Lisfranc amputation. Average follow-up was 13 months (range, 3 weeks to 51 months). One of the lesions recurred 4 years later.

Solitary renal cell carcinoma metastasis to the hand: the need for wide excision or amputation.

Metastatic renal cell carcinoma responds poorly to chemotherapy or radiation therapy and is associated with a dismal survival rate. In cases of a solitary acrometastasis, the literature supports complete resection of the lesion in an effort to prolong survival. We report a patient who presented with a solitary metachronous renal cell metastasis to the middle phalanx of the index finger. The lesion was correctly identified as a renal cell metastasis and aggressive surgical management was performed with curative intent.

Chondrosarcoma of bone: analysis of 108 cases and evaluation for predictors of outcome.

Chondrosarcoma is the second most common malignant bone tumor and is relatively unresponsive to chemotherapy and radiation regimens. In addition, the clinical course of chondrosarcoma is difficult to predict. The purpose of this study was to review the authors' experience with chondrosarcoma and ascertain any factors related to prognosis and clinical outcome. The medical records of 108 patients followed up for a minimum of 2 years were retrospectively reviewed. There were 31 low-grade and 77 high-grade chondrosarcomas. One hundred one patients underwent surgical resection. There was a statistically significant association between positive margins and local recurrence, metastasis, and death. Tumor grade was not predictive of outcome. Proliferation indices (MIB-1 expression determination through immunohistochemistry) were quantitated in 39 patients. A significant association was seen between MIB-1 expression and recurrence and death. Thus, objective quantitation of tumor proliferation was more predictive than was histologic grade of outcome in chondrosarcoma. Although histologic grade continues to be the standard grading system for chondrosarcoma, the current study contributes to ongoing research and validation of alternative techniques that may be more reliable in guiding prognosis and treatment of chondrosarcoma.

Tenascin-C splice variant adhesive/anti-adhesive effects on chondrosarcoma cell attachment to fibronectin.

Tenascin-C is an oligomeric glycoprotein of the extracellular matrix that has been found to have both adhesive and anti-adhesive properties for cells. Recent elucidation of the two major TNC splice variants (320 kDa and 220 kDa) has shed light on the possibility of varying functions of the molecule based on its splicing pattern. Tenascin-C is prominently expressed in embryogenesis and in pathologic conditions such as tumorogenesis and wound healing. Fibronectin is a prominent adhesive molecule of the extracellular matrix that is often co-localized with tenascin-C in these processes. We studied the chondrosarcoma cell line JJ012 with enzyme-linked immunoabsorbance assays, cell attachment assays and antibody-blocking assays to determine the adhesive/anti-adhesive properties of the two major tenascin-C splice variants with respect to fibronectin and their effect on chondrosarcoma cell attachment. We found that the small tenascin-C splice variant (220 kDa) binds to fibronectin, whereas the large tenascin-C splice variant (320 kDa) does not. In addition, the small tenascin-C splice variant was found to decrease adhesion for cells when bound to fibronectin, but contributed to adhesion when bound to plastic in fibronectin-coated wells. Antibody blocking experiments confirmed that both the small tenascin-C splice variant and fibronectin contribute to cell adhesion when bound to plastic. The large tenascin-C splice variant did not promote specific cell attachment. We hypothesize that the biologic activity of tenascin-C is dependent on the tissue-specific splicing pattern. The smaller tenascin-C isoform likely plays a structural and adhesive role, whereas the larger isoform, preferentially expressed in malignant tissue, likely plays a role in cell egress and metastasis.

The clinical significance of tenascin-C splice variant expression in chondrosarcoma.

OBJECTIVES: Tenascin-C (TNC) is an oligomeric glycoprotein of the extracellular matrix that is prominently expressed in malignant tumors. The purpose of this study was: (1) to determine the in vitro TNC splicing pattern in cultured human chondrocytes and chondrosarcoma cells, (2) to determine the in vivo TNC splicing pattern in clinical chondrosarcoma specimens, and (3) to perform survival analysis based on the TNC splicing pattern of the tumor specimens. METHODS: Human articular chondrocytes and chondrosarcoma cells (cell line JJ012) were grown in a three-dimensional alginate bead system and harvested at two time points. Semiquantitative reverse transcription polymerase chain reaction (RT-PCR) was used to determine the in vitro TNC splicing pattern for the two cell types. Clinical chondrosarcoma specimens were obtained intra-operatively and underwent RT-PCR to determine the in vivo TNC splicing pattern. Specific immunohistochemical staining for the large TNC splice variant was performed on the clinical specimens. Survival analysis was used to determine the association between the specific TNC splicing pattern and survival. RESULTS: The in vitro mRNA expression pattern of TNC in normal human articular chondrocytes was characterized by a high ratio of the small to the large splice variant (TNC(small):TNC(large)), whereas the in vitro mRNA expression pattern for cultured chondrosarcoma cells was characterized by a low TNC(small):TNC(large) ratio. Clinical chondrosarcoma specimens with a lower TNC(small):TNC(large) ratio showed a trend towards decreased survival. The TNC splicing pattern of these specimens was verified through specific immunohistochemical staining for the large TNC isoform. CONCLUSIONS: The specific TNC splicing pattern may have clinical significance in chondrosarcoma. TNC expression may therefore play a future role in objective tumor grading and novel therapeutic approaches to this malignancy.