Angiomatoid fibrous histiocytoma: Clinicopathological spectrum of five cases, including EWSR1‑CREB1 positive result in a single case.

Background: Angiomatoid fibrous histiocytoma (AFH) is an unusual soft tissue tumor (STT), characterized by recurrences, but rarely metastasis. Later, certain molecular signatures have been identified underlying this tumor, which at times, is either underdiagnosed as a benign vascular tumor, or over diagnosed as a high‑grade pleomorphic sarcoma, including a malignant fibrous histiocytoma. Materials and Methods: Over a 14‑year‑period, five diagnosed cases of AFH were analyzed. Results: Five tumors occurred in three males and two females, over a wide age‑range (median = 21, mean = 30 years); mostly in the extremities (4) (80%). Microscopically, most tumors were circumscribed, comprising large, blood‑filed spaces with surrounding histiocytic cells and a “cuff” of lymphoplasmacytic cells. Three tumors revealed solid growth pattern with polygonal to spindle cells, including myxoid matrix in one of these tumors. On molecular analysis, this tumor exhibited EWS‑CREB transcript. Immunohistochemically, various tumors were positive for CD68 (n = 2/2), epithelial membrane antigen (n = 3/4), CD99/MIC2 (n = 2/3), and desmin (n = 1/4). All tumors were surgically excised. On follow‑up (n = 2), a single patient, who underwent wide‑excision was free‑of‑disease (24 months), while another patient had a recurrence 4 months post tumor excision. Conclusions: This forms as the first documented series on clinicopathological features of AFH, a rare STT, from our country. Significant clinicopathological features include younger age, extremities as commonest site and histopathological appearance of blood‑filled spaces with surrounding “cuff” of histiocytic cells and lymphocytes. Tumors with unusual histopathological tumor patterns require molecular confirmation. Surgical resection remains the treatment mainstay.

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.

Osteoblastoma: a study of 12 cases.

This study comprises of 12 cases of osteoblastoma. There were 8 males and 4 females, with a mean age of 17.8 years. The vertebral column, including the sacrum was the most frequent site (10 of 12 cases). Radiologically the lesions were lytic, well circumscribed and expansile. The histology consisted of intercommunicating osteoid seams lined by plump osteoblasts with numerous intervening ectatic stromal vessels. Despite these characteristic features, the distinction of osteoblastoma from osteoblastic osteosarcoma can at times be very problematic. The lack of lace-like osteoid or sheets of osteoblasts, and inconspicuous mitotic activity are useful distinguishing features. The purpose of this communication is to highlight the microscopic features for the correct recognition of osteoblastoma and its distinction from other osteoid forming bone lesions.

Recurrent melanotic neuroectodermal tumour of infancy of the epididymis and testis: a case report.

Melanotic neuroectodermal tumor of infancy or melanotic progonoma is an uncommon tumor, presenting in infants. The epididymis and testis are rare sites of occurrence. This tumor can be confused with round cell tumor (RCT). Since the treatment modality and prognosis of melanotic progonoma and RCT are very different, it is imperative to make a correct diagnosis.

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.