Posterior Scleral Choristomas and Trigeminal Lipoma in the Organoid Nevus Syndrome

Abstract

The organoid nevus syndrome is a rare neuromyocutaneous disorder. The authors describe two cases of variable severity, document posterior scleral calcific choristomas associated with limbal choristomas, discuss surgical management, and describe a new finding of trigeminal lipoma.O rganoid nevus syndrome (ONS), known also as linear nevus sebaceous syndrome (LNSS) or Schimmelpenning-Feuerstein-Mims (SFM), is a neuromyocutaneous disorder of somatic mosaicism with multiple ocular, neurologic, and dermatologic abnormalities. The majority of cases are diagnosed in early childhood, and the severity of defects is highly variable. The most characteristic ocular manifestations include epibulbar choristoma, eyelid coloboma, and calcified posterior scleral choristoma. We report two cases of ONS with these defects, discuss the variable outcome in their treatment, and report a new finding of trigeminal lipoma in one case. Case Reports Case 1A 6-year-old boy, product of a normal gestation and delivery, was referred for evaluation of a right epibulbar choristoma, left lipodermoids, and left upper eyelid coloboma. A sebaceous nevus (linear sebaceous nevus of Jadassohn) extended from the left malar eminence into the scalp. Systemic workup was negative, and he did not have seizures. Bilateral white intrascleral opacities extended superonasally from the optic nerve (Figure 1). Visual acuity was 20/20 bilaterally. The epibulbar choristoma and lipodermoids were excised and the eyelid coloboma was repaired without complication. Case 2A 1-day-old girl, product of an uncomplicated gestation and delivery, was referred for eyelid and corneal malformations. A sebaceous nevus extended from the left midface into the scalp. Eyes blinked to light, pupils were reactive, and intraocular pressures were normal. A 50% left upper lid coloboma with a pedunculated polyp at the left lateral canthus was present. A left epibulbar choristoma extended from the colobomatous lid skin to the superior limbus ( Figure 2); a smaller choristoma was present contralaterally. Bilateral patchy corneal neovascularization and corectopia were present. The left crystalline lens exhibited nasal cortical opacification. Funduscopy revealed bilateral optic nerve hypoplasia and bilateral superonasal creamy white patches deep to the retina (Figure 3). Ultrasound and computed tomography demonstrated calcification of these intrascleral lesions. Magnetic resonance imaging demonstrated hypoplastic extraocular muscles, medial tethering of the left optic nerve, bilateral optic nerve hypoplasia, left temporal lobe hypoplasia, a large temporal arachnoid cyst, and a T1 hyperintense lesion along the trigeminal nerve, consistent with trigeminal lipoma (Figure 4). Remaining systemic workup was negative.Hypoglobus and fixed hypotropia of the left eye in Case 2 persisted despite debulking the anterior choristoma and mobilization of the eyelid. Left corneal neovascularization partially obscured the visual axis. The left upper eyelid defect was closed by Supported by the