Adenocarcinoma of the Retinal Pigment Epithelium Arising in Conjunction with Late Recurrence and Systemic Metastasis of Retinoblastoma

Abstract

In 1974, an 8-month-old male was diagnosed with bilateral retinoblastoma. His left eye was enucleated, while the right eye was salvaged with a combination of external beam radiotherapy (4,000 cGy total, divided in 20 fractions) and retinal laser treatment. Thirty-nine years later, he developed intraocular recurrence of retinoblastoma with extrascleral spread. Histopathological examination also identified a second distinct malignancy, retinal pigment epithelium adenocarcinoma, arising in continuity with the retinoblastoma. Further investigation revealed foci of metastatic retinoblastoma in his parotid gland. He was subsequently treated with a combination of orbital exenteration, extensive neck dissection, and resection of metastatic foci, followed by a high-dose ablative chemotherapeutic regimen consisting of cisplatin, vincristine, and cyclophosphamide. Although very rare, late recurrence of retinoblastoma with systemic metastasis is possible, and continued clinical observation and appropriate long-term follow-up should be considered. Additionally, it is important to consider a second primary intraocular tumor in the differential diagnosis, especially in a patient with heritable retinoblastoma who has undergone radiation therapy.

Retinal Pigment Epithelium Adenoma and Adenocarcinoma: A Review

“…One case of RPE adenocarcinoma was detected on histopathology in an eye enucleated for late recurrence of retinoblastoma (RB; bilateral, the other eye was enucleated) with metastases [28]. The authors postulated that an unsuspected RPE tumour arising from RPE hyperplasia occurred secondary to the focal treatment of RB, or that both tumours arose from reactivation of a common cancer stem cell, or that changes in the microenvironment related to the development of RPE adenocarcinoma permitted the exit from dormancy of an RB cancer stem cell [28]. Fiorentzis et al [29] reported a case of an RPE adenoma imitating a malignant transformed melanocytoma at the optic nerve, 10 years after treatment of a peripheral choroidal melanoma in the same eye.…”

“…All these conditions have one common denominator, the abnormal proliferation of the RPE incited by various stimuli. One case of RPE adenocarcinoma was detected on histopathology in an eye enucleated for late recurrence of retinoblastoma (RB; bilateral, the other eye was enucleated) with metastases [28]. The authors postulated that an unsuspected RPE tumour arising from RPE hyperplasia occurred secondary to the focal treatment of RB, or that both tumours arose from reactivation of a common cancer stem cell, or that changes in the microenvironment related to the development of RPE adenocarcinoma permitted the exit from dormancy of an RB cancer stem cell [28].…”