Primary myoepithelial carcinoma of rib bone: Morphology, immunohistochemical evaluation and diagnostic dilemma in an unusual case.

Myoepithelial tumors are most commonly seen as salivary gland tumors. Tumors of similar morphology and nomenclature are also seen rarely in soft tissue, skin, lungs and breast. Bone is an uncommon anatomical site for occurrence of myoepithelial tumors. Histologically, they have variable admixture of epithelial elements in a gamut of patterns with myxoid matricial background. Most of these are benign with very anecdotal reports of malignant counterpart, myoepithelial carcinoma. Herein we describe an extremely rare case of a malignant myoepithelial tumor arising from the rib which owing to unusual location and immunohistochemical profile was diagnostically challenging.