increased Harderian gland tumor incidence increased Harderian gland adenocarcinoma incidence MP:0014128 greater than the expected number of a malignant neoplasm of acinar epithelial cells in the Harderian gland, occurring in a specific population in a given time period; these usually are larger than adenomas and may cause facial selling and/or exophthalmos; they are highly cellular and disorganized compared to adenomas, with piling up of pleomorphic cells; areas of medullary or solid growth patterns are common; there may necrosis or hemorrhage, invasion beyond the orbit, and distant metastasis to the lungs, local lymph nodes, thymus or liver Harderian gland adenocarcinoma Harderian adenocarcinoma