B Deepthi

Abstract

Malignant bone tumors with epithelial differentiation are extremely rare. A primary carcinosarcoma arising in bone is characterised by the presence of both epithelial and mesenchymal differentiation. Herein we report an extremely rare case of primary chondroblastic osteosarcoma with true divergent glandular differentiation in a twenty-nine year old female. Microscopic sections reveal a high-grade chondroblastic osteogenic sarcoma with definite areas showing neoplastic osteoid formation and nests, cords and acinar (glandular) structures with cytokeratin positivity suggesting definitive epithelial glandular differentiation. Our case illustrates the ability of osteosarcomas to show epithelial differentiation characterized both by cytokeratin expression and differentiation to adenocarcinomatous cells displaying distinct glandular differentiation   Keywords: Cytokeratin, Divergent glandular differentiation, Osteosarcoma

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Abstract

Introduction: Mesenchymal tumours of gastrointestinal tract are a heterogenous group of nonepithelial tumours of variable mesenchymal cell histogenesis. Gastrointestinal stromal tumour (GIST) is the most common primary mesenchymal tumour of the gastrointestinal tract and spans a clinical spectrum from benign to malignant. This study evaluated the clinicopathological morphological and immunohistochemical features of GIST of the intestinal tract. Materials and Methods: All evaluable cases of mesenchymal tumors of the gastrointestinal tract were studied from January 2007 to December 2012. Tissue microarray was constructed and Immunohistochemical expression of CD 117, CD 34, DOG1, SMA, S100, Ki 67 were studied. Results: Gastrointestinal stromal tumours were the most common mesenchymal tumours of the gastrointestinal tract accounting to 77.96%. The median age of presentation was 51 years with near equal sex preliction with early clinical presentation. The gastric tumours were of significantly bigger size with increased expression of CD 34. Majority of tumors were of bigger size (>10 cm, 47%) thereby increased number of tumours in high risk category (76%). Spindle cell pattern was the most common morphology (69.5%). Epitheliod histology was significantly associated with pleomorphism and atypia (p value – 0.029). Inclusion of anatomic site into the risk category will help in better stratificaion. High risk tumours showed significant areas of necrosis when compared with low risk tumours (p value- 0.0156). Tumours of older age group (>40 years) showed significant mitotic activity (p value 0.04). DOG1 is a very sensitive (97.8%) marker for GIST. A wide immunopanel with emphasis on DOG 1 positivity for precise diagnosis of GIST and classification of mes enchymal tumors of the GI tract. Keywords: DOG 1, Mesenchymal tumours, Gastrointestinal stromal tumour, Clinicopathological, Immunohistochemical features.

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