C-kit expression in human osteosarcoma and in vitro assays.

Biologic agents targeting oncogenes have encourage researchs trying to correlate the role of tyrosine kinase in the pathogenesis of tumours. Osteosarcoma is a high grade aggressive neoplasm with poor survival. Our aim was to investigate c-kit immunoexpression, its prognostic relevance for patients with osteosarcoma, and the effect of imatinib mesylate (STI571) on proliferation and invasion of the human osteosarcoma cell line.A retrospective immunohistochemical study was performed on archival formalin-fixed paraffin-embedded specimens from 52 patients with high-grade primary osteosarcoma of extremities treated at the Pediatric Oncology Institute (IOP, GRAAC) and archived in the Department of Pathology, Federal University of São Paulo. Only pre-chemotherapy specimens were analyzed. Strongly stained cytoplasm and membrane cells were taken as positive. Human osteosarcoma cells from line MG-63 were incubated and the inhibitory effect of imatinib mesylate (STI571) on cell proliferation and invasion was studied. In 24 cases (46.15%), c-kit was expressed by the cells and c-kit-positive tumors exhibited lower necrosis post-chemotherapy. No correlation was found between c-kit expression and overall and disease-free survival. Imatinib mesylate decreased the rates of cell growth of osteosarcoma cells in low doses and invasion in high doses C-kit-positive tumors had worse response to chemotherapy and imatinib mesylate can play a role in blocking or decreasing the rate of growth of osteosarcoma cells, but not the invasive capacity of these neoplastic cells. These data suggested that imatinib mesylate could be a therapeutic target of strategies against osteosarcoma tumors. Further studies are necessary to confirm this indication.

Infiltrating syringomatous adenoma of the nipple.

Infiltrating syringomatous adenoma of the nipple is a rare, benign, locally invasive tumor with recurrence potential, showing sweat duct differentiation. It can clinically, radiologically and pathologically mimic cancer. Histopathologically, it must be distinguished from florid papillomatosis, adenosquamous carcinoma, adenoid cystic carcinoma and sclerosing syringomatous carcinoma. A 44-year-old woman presented with pain on the right nipple for 7 days. On physical exam there was an irregular nodule on nipple area with edema. The skin was intact. The ultrasound showed a hypoechoic irregular nodule measuring 7.5 mm in the nipple area. The mammography was unspecific. The lesion was surgically removed and histopathologically, the tumor was composed of ducts and tubules lined with a double-layered epithelial cells. The lining cells were small, cuboidal with a central nuclei and eosinophilic nuclei. The stroma was dense with lymphocytes and plasma cells, and compressed many of the ducts that contained a comma or tadpole-shape, giving an impression of a syringoma. Some ducts were slightly dilated with squamous metaplasia. Some of these cysts were connected with the overlying epidermis. Mitotic figures were rare and no pleomorfism or hyperchromasia was observed. At the periphery, the ducts invaded muscular fibers of the nipple. The surgical margins were free of neoplastic involvement. Patient has no signs of progression of disease in 1 year of follow-up.

Primary orbital mesenchymal chondrosarcoma: a case report and literature review.

BACKGROUND: Mesenchymal chondrosarcoma (MC) is a subtype of chondrosarcoma, with an incidence varying from 1 to 8% of all chondrosarcomas. It is an aggressive neoplasm with a high tendency for late recurrence and occasional delayed distant metastasis. Orbital MC is very rare, and only approximately 30 cases have been described in the literature. We describe here one case of primary orbital MC. CASE REPORT: A 14-year-old boy without a past medical history presented with a 1-month history of progressive proptosis on the right eye. Computed tomography (CT) scans of the orbit revealed a right intraconic lesion, with areas of calcification. The lesion was excised. Histopathological analysis revealed that the tumor had a biphasic pattern, showing a combination of small cell malignancy and well-differentiated cartilage. Immunohistochemistry examination revealed a diffuse membrane expression of CD99 on the small cell malignancy; S-100 was positive only within the cartilage component. The patient received chemotherapy, and no metastatic disease was found at the 2-month follow-up. CONCLUSION: Although rare, MC should be considered in the differential diagnosis of a well-circumscribed orbital lesion in young adults, especially when CT scans reveal areas of calcification within the tumor.

Angiosarcoma of the gallbladder: case report and review of the literature.

A 62-year-old white woman with an unremarkable past medical history presented with acute cholecystitis. A cholecystectomy was performed, revealing an acute hemorrhagic and chronic cholecystitis associated with cholelithiasis. Two months after the operation, the patient developed a massive hemoperitoneum and died by hypo-volemic shock. At autopsy, an angiosarcoma measuring 5 cm in diameter was found in the liver, at the site of the gallbladder fossa. There were multiple hepatic, splenic, ovarian and peritoneal metastases and a massive hemoperitoneum consisting of 8 L of blood and blood clots. Review of the tissue sections from the patient's gallbladder confirmed the presence of an acute hemorrhagic and chronic cholecystitis and also revealed residual foci of an angiosarcoma. A review of eight previously reported cases of gallbladder angiosarcoma is also presented.

Mammary myofibroblastoma: report of two cases with fine-needle aspiration cytology and review of the cytology literature.

Fine-needle aspirates from two histologically, immunohistochemically, and ultrastructurally confirmed mammary myofibroblastomas (MM) of two elderly women revealed abundant, randomly arranged single and clustered benign spindle-shaped mesenchymal cells with scant cytoplasm and elongated or oval nuclei displaying a finely granular chromatin pattern and inconspicuous nucleoli. In one case a few cells showed inconspicuous nuclear grooves. The aspirated tumor cells from the other case stained positively with desmin and CD34 antibodies and negatively with cytokeratin and S-100 protein antibodies, in keeping with an MM. A review of the literature was briefly presented.