Lacrimal gland adenocarcinoma with widespread metastasis in a domestic rabbit

An 11-y-old spayed female American rabbit (Oryctolagus cuniculus) was presented for autopsy with a left maxillary mass. Grossly, the mass was firm, pale-tan, and firmly adhered to the left maxillary bone. Similar masses were observed in the lungs, liver, and kidneys. Histologically, the mass was poorly demarcated, unencapsulated, highly infiltrative, and densely cellular, consisting of neoplastic cuboidal-to-polygonal cells arranged in acini and occasional tubules anchored in a delicate fibrous stroma. Neoplastic cells were positive for anti-keratin/cytokeratin AE1/AE3 antibody. Similar neoplastic cells were present in the lungs, liver, and kidneys. Histopathologic and immunohistochemical findings were consistent with an adenocarcinoma. Based on the anatomy and histology of the rabbit lacrimal gland and adjacent lacrimal gland structures, we concluded that this was an adenocarcinoma arising from the accessory lacrimal gland. To our knowledge, adenocarcinoma originating from the accessory lacrimal gland has not been documented previously in a rabbit.