PMC4506902_01
(A) Clinical appearance prior to surgery demonstrated a right sided, superotemporal mass. (B) Coronal CT showed a well-circumscribed mass superotemporal to the right globe causing inferior displacement. (C) Axial CT reveals a mass posterolateral to the right globe. The white asterisk denotes a hyperdense area which was the site of the initial incisional biopsy and was histologically consistent with a pleomorphic adenoma. The black asterisk indicates a hypodense area corresponding to the myoepitheliomatous part of the tumor seen after complete excision.
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F1
Clinical examination revealed a palpable, firm right superotemporal mass and associated right-sided proptosis (Fig. 1A). A computed tomography (CT) scan revealed a well-circumscribed mass of heterogeneous density in the right lacrimal gland fossa with no signs of bony erosion (Fig 1B & C).
(A) Initial incisional biopsy revealed pleomorphic adenoma; (B) epithelial cells line duct-like structures which are surrounded by myoepithelial cells (C) Subsequent excisional biopsy again revealed a pleomorphic adenoma component; (D) epithelial cells lining duct-like structures surrounded by myoepithelial cells; (E) clear cells within trabecular component of the tumor; (F) higher magnification shows large vacuolated cells with displaced nuclei and clear cytoplasm; (G) strong immunoreactivity for cytokeratins AE1,3 in clear cells; (H) focal smooth muscle actin immunoreactivity in clear cells. (hematoxylin and eosin, A. 25X, B.100X, C. 25X, D. 100X, E. 100X, F. 100X; peroxidase anti-peroxidase G. 100X, H. 100X)
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F2
Microscopic examination showed duct-like structures bordered by epithelial cells surrounded by darker, myoepithelial cells (Fig. 2A & B). The first component had duct-like structures lined by low cuboidal epithelial cells surrounded by myoepithelial cells (Fig 2C & D). The second component was trabecular with small islands of cells with large vacuoles, displaced nuclei and clear cytoplasm (Fig 2E & F). Immunostaining was strongly positive for cytokeratin AE1,3 (Fig. 2G) and vimentin. There was focal positivity for smooth muscle actin (SMA) (Fig. 2H) and MAK6, with rare positivity for S100.