Association of a suprasellar mass and intraocular retinoblastoma: a variant of pineal trilateral retinoblastoma?

Abstract

'Trilateral retinoblastoma' designates the association of bilateral retinoblastomas with an ectopic (non-metastatic) intracranial primitive neuroectodermal tumor (PNET). Although the intracranial tumor, usually located in the pineal region, is seen 2-3 years after discovery of the bilateral ocular tumors, variant presentations do occur. The intraocular tumor can be unilateral, and the intracranial tumor can be suprasellar, presenting before the retinal lesions. A 4-month-old boy presented with irritability, vomiting and nystagmus. Head CT revealed a large calcified sellar-suprasellar mass. Ocular examination disclosed white macular lesions in the right fundus. He was taken to surgery where subtotal resection of the sellar-suprasellar mass was achieved. Microscopic examination showed a primitive, small, round, blue cell tumor consistent with retinoblastoma. The right ocular lesions, also consistent with retinoblastoma, were treated by cryosurgery. The appearance of a suprasellar PNET can precede the appearance of retinal masses in retinoblastoma. The literature suggests that patients with 'sellar' trilateral retinoblastoma have characteristics that differ from patients with a pineal region trilateral retinoblastoma: the intracranial mass more often presents initially; it occurs at a younger age; it is predominant in females, and is more often associated with unilateral ocular lesions. Retinal screening of patients with suprasellar PNET and other atypically located PNETs may disclose more cases of sellar 'trilateral retinoblastoma' and hereditary retinoblastomas. This will have implications on genetic counseling as siblings harboring the disease may be diagnosed and treated at an earlier stage.