To report the clinicopathological features of a case with adult onset asthma with periocular xanthogranuloma.

Background: Adult-onset asthma with periocular xanthogranuloma (AAPOX) is a rare and recently defined disease with unknown etiology. It is a part of adult orbital xanthogranulomatous diseases.

Case report: A 53 year old man with history of asthma presented with painless slow-growing bilateral erythematous and firm lid swelling of few months duration. Ocular exams were normal except for the bilateral periorbital swelling and left lateral rectus muscle thickening in the orbital CT scan. Histopathologic evaluation of eyelid and the lateral rectus muscle showed infiltration of orbital tissue by mononuclear foamy histiocytes and dispersed Touton giant cells (multinucleated giant cells with ring of nuclei around central homogenous eosinophilic zone and a pale foamy area at the periphery) among the aggregates of lymphoid follicles with germinal centers.

Periorbital swelling and asthma should raise the suspicion of adult onset asthma and periocular xanthogranuloma. Surgery, radiation and local corticosteroid injection are suggested for local treatment. Systemic treatment includes oral corticosteroids, methotrexate and cytotoxic medications. AAPOX should be distinguished from chronic orbital disorders, such as inflammatory pseudotumor, low grade lymphoma, and infectious orbitopathies.