Extensive Sclerosis ("mummification") in Lacrimal Gland Pleomorphic Adenoma May Indicate Neighboring Malignant Transformation.

Salivary gland pleomorphic adenomas not uncommonly show extensive sclerosis ("dense hyalinization," "coagulative necrosis," or "mummification"), which arise spontaneously or after prior surgery, and this change is considered a high-risk factor for malignant transformation of benign salivary adenomas. While minor hyalinization is common in lacrimal gland adenomas, massive sclerosis-where almost all (90% or more) of the tumor is replaced by an amorphous hyaline material-is extremely rare. Four patients (2 males) are described in whom, despite not having an acute inflammatory episode, their lacrimal gland tumor showed marked sclerotic necrosis within the majority of either the benign or malignant parts of the tumor. Three tumors had evidence of malignant change, 2 to adenocarcinoma, and 1 to mucoepidermoid carcinoma, but none of the malignant areas showed perineural or endovascular invasion. Extensive sclerosis in association with a lacrimal gland pleomorphic adenoma (LGPA) is rare (4/110 of the cases) and-as with salivary adenomas-appears to be associated with a high chance of associated malignant change. Both the surgeon and the histopathologist should regard extensive sclerotic necrosis as a harbinger for malignant change in association with benign pleomorphic adenomas of the lacrimal gland.