Kimura disease of the orbit and ocular adnexa

Kimura disease (KD) is a distinct clinicopathologic entity that has been the subject of considerable confusion and debate. Although common in Asia, KD rarely occurs in non-Asian patients. Kimura disease shares both clinical and histopathologic features with angiolymphoid hyperplasia with eosinophilia (ALHE). Because of this overlap and the rarity of KD in Europe and the United States, KD and ALHE have been used synonymously in the Western medical literature, as they were thought to represent variations of the same disease. Some pathologic reports have called for distinguishing KD and ALHE as two separate entities, based on their histologic features. Kimura disease occurs most commonly in the head and neck region and has been described in the orbit, eyelids, and lacrimal gland more frequently than ALHE. Because both diseases can cause proptosis, lid swelling, ocular dysmotility, or a palpable mass, they should be considered in the differential diagnosis of orbital lesions occurring in adults. We report two cases of KD involving the orbit and ocular adnexa, and review additional cases reported in the literature. The ophthalmic literature does not clearly reflect the current understanding that KD and ALHE are best considered two separate clinicopathologic entities.