Periocular Adult-Onset Xanthogranuloma (AOX) Initially Misdiagnosed as Xanthelasma: A Case Report

Adult orbital xanthogranulomatous disease (AOXGD) is a heterogeneous group of syndromes that are generally rare. One of the proposed sub-classification of AOXGD includes 4 subtypes, which are differentiated based on their variable clinical features: Adult-onset xanthogranuloma (AOX), Necrobiotic xanthogranuloma (NBX), Erdheim-Chester disease (ECD), and Adult-onset asthma and periocular xanthogranuloma (AAPOX). These entities share the finding of “Hallmark” cells histopathologically, which are foamy histiocytes and Touton-type giant cells. Diagnosis of each of these can be challenging and often misleading in management. We have faced this interesting case of a 54 year-old female who presented with multiple yellowish periocular skin lesions for several years with the presumed diagnosis of simple xanthelasma based on the histopathological examination of these lesions previous excisional biopsy in another institution. The correct diagnosis of AOX was not made until the patient presented to our tertiary eye center for better cosmetic treatment. We believe that this entity is being overlooked owing to its rarity. Ophthalmologists, dermatologists, general practitioners and pathologists should consider AOXGD in their daily practice whenever applicable.