Retinoblastoma in a 23-year-old adult treated with primary intra-arterial and intravitreal chemotherapy.

Intra-arterial chemotherapy (IAC) continues to provide a globe-sparing alternative as primary treatment for retinoblastoma with few adverse events. While there is growing evidence to highlight the utility of IAC in children with retinoblastoma, adult cases treated with primary IAC have not previously been characterized. We describe a rare case of Group D retinoblastoma in a 23-year-old adult treated successfully with IAC and intravitreal chemotherapy. This is a retrospective case report of a single patient. Subsequent to IAC and intravitreal chemotherapeutic treatments, at last follow-up 14 months following initial presentation and 8 months since last treatment, the retinoblastoma demonstrated complete regression into a partially calcified scar, with complete resolution of intravitreal and subretinal seeds and no evidence of tumor recurrence. Visual acuity improved to 20/30 in the left eye. There were no adverse events from therapy. Despite its rarity, it is important to consider retinoblastoma in the differential diagnosis of a white mass, even in an adult. Furthermore, this case highlights the utility of IAC for retinoblastoma, despite older patient age.

Introduction

Retinoblastoma is an intraocular tumor found with overwhelming prevalence in children, with 95% of cases detected before the age of 5 years.[12] The presentation and diagnosis of retinoblastoma in adults, defined as age greater than 20 years, is comparatively rare.[3] While IAC is increasingly used as a globe-sparing alternative to traditional treatment methods for advanced retinoblastoma in children, the literature is currently lacking in its use for treating adults, largely owing to the disease's rarity in this age group. Herein, we present a case of an adult treated successfully with IAC as primary treatment for advanced retinoblastoma.

Case Report

A 23-year-old Caucasian male with no past medical history and no family history of retinoblastoma presented with progressive painless vision loss in the left eye. Visual acuity was 20/20 in the right eye and 20/300 pinhole 20/70 in the left eye. Pupils showed no relative afferent defect, and intraocular pressure was 14 mmHg in each eye. The right eye was normal. Examination of the left eye revealed moderate vitreous cellularity and a large endophytic vascular mass in the inferonasal quadrant, measuring 13 mm × 12 mm in base and 6.3 mm in thickness. There were surrounding subretinal fluid, exudation, and vitreous and subretinal debris [Figure 1a].

Figure 1

Photographic montage of the tumor on initial presentation (a). A large white mass with overlying vitreous hemorrhage and debris is noted. At last follow-up (b), a partially calcified scar remains, without evidence of active retinal or vitreous seeds

Minor intratumor hyperreflectivity on ultrasonography, concerning for calcium, was noted. These features [Figure 2a–d] were suggestive of retinoblastoma, despite its rarity in adults. Full physical examination, complete blood count, and blood and urine cultures were unremarkable. A diagnosis of Group D retinoblastoma was established,[4] and intra-arterial chemotherapy (IAC) was instituted. The tip of a microcatheter was placed at the orifice of the ophthalmic artery to infuse melphalan (5 mg) and topotecan (1 mg).[5] The patient underwent three cycles of IAC, with an interval of 5 weeks between the first and second treatments and a 7-week interval between the second and third treatments, combined with administration of four intravitreal melphalan injections (20 μg/0.1 cc) to the left eye. Each intravitreal injection was given at regular 5-week intervals. At last follow-up 14 months following initial presentation and 8 months since last treatment, the retinoblastoma demonstrated complete regression into a partially calcified scar, with complete resolution of intravitreal and subretinal seeds and no evidence of tumor recurrence [Figures 1b and 2e, f]. Visual acuity improved to 20/30 in the left eye. There were no adverse events from therapy.

Figure 2

Ultrasonography of the tumor at initial presentation (a) with no obvious calcification. Spectral Domain Optical Coherence Tomography (SD-OCT) of the fovea (b) at initial presentation demonstrated minor overlying vitreous seeds and whereas (c) more peripheral SD-OCT showed larger preretinal seeds. At last follow-up, ultrasonography (d) demonstrated tumor regression and spectral-domain optical coherence tomography showed normal fovea horizontally (e) and vertically (f)

Discussion

While retinoblastoma is the most common primary intraocular malignancy of childhood, retinoblastoma in adults is exceedingly rare.[67] A literature search was executed on PubMed and Ovid MEDLINE with the MeSH terms “eye cancer, retinoblastoma” and “adult” or “adult children,” which identified 26 cases of reported retinoblastoma in adults. This is the first report, to the authors' knowledge, of IAC as primary treatment of retinoblastoma in an adult (≥20 years old). We have previously used IAC as secondary treatment for active retinoblastoma in a 32-year-old adult.[6]

Studies on adults with retinoblastoma reveal more advanced disease (Group D or E) often requiring enucleation or exenteration.[27] In one case series of eight patients, the mean age of presentation was 30 years, and the mean duration of symptoms was 22 months.[2] The cause of retinoblastoma in adults is speculated to be reactivation of previously undiagnosed, spontaneously regressed, or arrested retinoblastoma (also termed retinocytoma/retinoma).[2] In one case series of three adult patients with retinoblastoma, all lesions were noted to be endophytic with vitreous seeds, and interestingly, two of three did not display calcification by ultrasonography.[7]

In closing, we describe a case of retinoblastoma in an adult treated with IAC as primary therapy. Despite its rarity, it is important to consider retinoblastoma in the differential diagnosis of a white mass, even in an adult. Furthermore, this case highlights the utility of IAC for retinoblastoma, despite older patient age.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.