Editor, J uvenile Xanthogranuloma (JXG) is a benign condition of unclear aetiology that can affect any organ and system. Typically, it presents as solitary red or yellow or yellow-to-brown cutaneous papule, plaque or nodular lesion. JXG may, however, occur as multiple lesions and possibly even arise extracutaneously and/or as disseminated systemic disease (Fan & Sun 2011). JXG represent the commonest type of non-Langerhan’s cell histiocytoses (LCH). Histologically, JXG consists of a well-demarcated mixed infiltrate of mononuclear histiocytes with eosinophilic to vacuolated cytoplasm and multinuclear giant cells (Touton giant cells) on a background of scattered lymphocytes, eosinophils, neutrophils and mast cells. Immunostaining confirms the morphological diagnosis of JXG, with the histiocytes being highlighted in the CD68 and CD163 stains. JXG is negative for protein S-100P andCD1a (Dehner 2003), differentiating this lesion from LCH. Ocular manifestations of JXG have been reported in approximately 10% of affected individuals (Yanoff & Perry 1995). Sporadically, JXG may present as a solitary corneoscleral limbal lesion in adult individuals. An adult solitary form of JXG, termed adult onset xanthogranuloma (AOX), shares many clinical and histological characteristics of the juvenile form (Gartmann & Tritsch 1963). Limbal AOX is extremely rare, and only nine cases have been reported so far in the literature. Hereby, we present the 10th case of limbal AOX in the literature, concerning a 67-year-old caucasian male, being the oldest reported to date with this condition. He presented with a 5-month history of a painless corneal nodule on his left eye; a smooth, yellowish, dome-shaped, well-circumscribed mass of 1.6 mm by 2.4 mm at the 6 o’clock position of the corneoscleral limbus (Fig. 1A). Systemic examination did not reveal any abnormality. Laboratory tests were all within normal limits. Following a 7-day unsuccessful topical steroid treatment, an excisional biopsy was performed with no recurrence after 7 months (Fig. 1B). Histopathological examination showed an extensive xanthogranulomatous inflammation within the cornea resulting in complete destruction of the stromal architecture, with focal infiltration into the overlying epithelium. The morphological and immunohistochemical features were consistent with AOX (Fig. 1C–F). To prevent recurrence and complications, early surgical resection is the treatment of choice for limbal AOX. Lamellar grafting may be considered in recurring lesions involving the cornea. The cause of AOX of the corneoscleral limbus remains unknown; the rarity of the condition and the lack of genetic information pose an additional barrier to the in-depth understanding of the aetiology of this condition. In conclusion, although rare, AOX should be included in the differential diagnosis of solitary corneoscleral limbal masses in patients of all age groups. Diagnosis should be based on the characteristic clinical and histopathological features, and surgical treatment should be initiated promptly to prevent sight-threatening complications.