Epithelioid myoepithelioma of lacrimal gland.

A rare case of myoepithelioma of the lacrimal gland composed exclusively of epithelioid cells is described.A 57-year-old female had been complaining for 1 month of progressive swelling of the temporal region of the left orbit. Computed tomography scan revealed a lesion involving the left lacrimal gland. The lesion was entirely removed en-bloc along with the lacrimal gland. Grossly, the tumour was a well-circumscribed 3.5×25×1.5 cm mass. An extensive sampling was performed. The surgical specimen was routinely formalin fixed and paraffin embedded. Sections 5-m thick were obtained and stained with haematoxylin-eosin. Immunostaining was performed on 5-m serial sections. Histologically, the lesion showed a solid pattern of growth and was composed exclusively of cells with epithelioid (plasmacytoid) features. Atypical myoepithelial cells, abnormal mitotic figures, necrosis and invasive growth throughout the tumour were absent. Myoepithelioma of the lacrimal gland is extremely rare, and thus far only seven cases have been reported. Of these cases, two were considered malignant and one potentially malignant . All but one showed spindle to cuboidal cells arranged in a solid or trabecular pattern . Myoepithelial cells are generally immunoreactive for S-100, vimentin, cytokeratin, desmin, m-actin and sm-actin. There is a considerable variation in the immunoreactivity for these antigens in our case, as in the seven previously reported cases. These differences may be dependent on the degree of differentiation .The size of the tumour prompted us to recommend a careful clinical follow-up. The patient had an uneventful post-operative course, and there has been no evidence of relapses over 24 months of follow-up.