Intraosseous myoepithelioma: A rare, distinct tumor entity

Primary musculoskeletal myoepithelial tumors (METs) are distinctly rare tumors and are being increasingly recognized as a result of improved diagnostic criteria and objective confirmation with immunohistochemical markers, including epithelial markers. Recent studies have unraveled distinct molecular mechanisms underlying these tumors. Herein, we present our second diagnosed case of an intraosseous MET that occurred in the tibia of a 37-year-old lady. The case is discussed with regards to current clinicopathological perspectives on these rather uncommon tumors, including our personal experience.

A study of histopathological features of medullary carcinoma of the thyroid: cases from a single institute in India.

BACKGROUND: The microscopic features of medullary carcinoma have been described in world literature, together with its behavior and molecular biology. However, no large study has been reported from India. AIMS: This study aims to analyse the clinical, and especially the pathological features of medullary carcinoma of the thyroid, and the surrounding thyroid. MATERIALS AND METHODS: In this study a total of 234 cases of medullary thyroid carcinoma (MTC) were gathered over a period of 3 decades. The clinical presentation, the microscopic features and the clinical outcome were analyzed. RESULTS: MTC was found to be twice as common in men as in women and for some reason it occurred 10 years earlier in women. The histology revealed certain interesting features like the presence of apoptosis in over half of the tumors, in addition to the other common and not so common histological findings (encapsulated variant, small cell variants, follicular pattern, rosettes, oncocytic change, osteosarcoma-like pattern, and cribriform pattern). The adjacent thyroid in about 19% of the cases showed optically clear nuclei in the follicles that were close to the tumor cells. These features were similar to those seen in papillary thyroid carcinoma. CONCLUSIONS: The thyroid adjacent to MTC showed nuclear changes, which are also found in papillary carcinoma of the thyroid. The occasional concurrent occurrence of these two tumors and the involvement of the RET gene in both medullary and papillary carcinomas, makes this observation worth discussing and studying further.

Mesenchymal chondrosarcoma: a series of 23 cases.

A total of 23 cases of mesenchymal chondrosarcoma were studied from the histopathology records spanning 23 years. There were 16 men and 7 women afflicted with this tumor and their mean age was 28.1 years. The radiological features, histology and treatment outcomes have been studied. Osseous and extra-osseous mesenchymal chondrosarcomas are compared and the differential diagnosis discussed.

Langerhans' cell histiocytosis: a clinicopathological study of 50 cases.

To analyze the clinicopathologic features and outcome of patients with Langerhans cell histiocytosis (LCH). Fifty cases of LCH accrued over a 15-year period were analyzed and classified as having unifocal, multifocal, or multisystem disease. Events regarding progression, relapse, or death were noted. The 50 cases comprised of 34 men and 16 women. 92% of the patients were less than 15 years of age and 46% were less than 2 years. Involvement by LCH was unifocal in 22, multifocal in 8, and multisystem in 20. Bone was the commonest site (92%), followed by lymph node (30%). The histological features were relatively uniform regardless of the clinical severity, and consisted of Langerhans cells, eosinophils, histiocytes, plasma cells, giant cells and fibrosis. The treatment consisted of surgery, chemotherapy, and/or radiotherapy. Response to treatment was poor in patients with multisystem disease. The histology of LCH is very characteristic and patients with age less than 2 years are more likely to have increased risk or morbidity and mortality, due to widespread disease.