K Iida1, K Shikishima, M Okido, S Sato, Y Masuda. 1. Department of Ophthalmology, Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan.
Abstract
BACKGROUND: A case of malignant myoepithelioma in the lacrimal gland is reported. CASE: The patient, a 77-year-old male with increasing proptosis in the left eye was referred to us. Steroid therapy was not effective, therefore lateral orbitotomy was performed. RESULT: On pathological examination, the proper structure of actini was normal, but the cord of actini revealed the destruction layer tapering into the surrounding area. The tumor was composed of sarcomatoid changes with spindle-shaped cells, collagen fibers, and myxoid pattern. immunohistochemically, tumor cells were positive for epithelial membrane antigen (EMA) and alpha-smooth muscle actin (alpha-SMA). Electronmicroscopy showed desmosomes in intercellular junctions. CONCLUSION: Recently, there have been attempts to distinguish myoepithelioma from pleomorphic adenoma on the basis of cellular organization. In our case, duct formation was less than in pleomorphic adenoma. Therefore we diagnosed this tumor as malignant myoepithelioma.
BACKGROUND: A case of malignant myoepithelioma in the lacrimal gland is reported. CASE: The patient, a 77-year-old male with increasing proptosis in the left eye was referred to us. Steroid therapy was not effective, therefore lateral orbitotomy was performed. RESULT: On pathological examination, the proper structure of actini was normal, but the cord of actini revealed the destruction layer tapering into the surrounding area. The tumor was composed of sarcomatoid changes with spindle-shaped cells, collagen fibers, and myxoid pattern. immunohistochemically, tumor cells were positive for epithelial membrane antigen (EMA) and alpha-smooth muscle actin (alpha-SMA). Electronmicroscopy showed desmosomes in intercellular junctions. CONCLUSION: Recently, there have been attempts to distinguish myoepithelioma from pleomorphic adenoma on the basis of cellular organization. In our case, duct formation was less than in pleomorphic adenoma. Therefore we diagnosed this tumor as malignant myoepithelioma.