Failure of globe conservation in a case of adult onset retinoblastoma.

Adult onset retinoblastoma is a rare intraocular malignancy. The majority of the cases are treated with enucleation, due to late presentation and advanced-stage tumors. Here we report a case of a 30-year-old female who presented with an intraocular mass with exudative retinal detachment in her right eye. B-scan ultrasound and magnetic resonance imaging (MRI) confirmed the diagnosis of retinoblastoma. In an attempt to salvage the globe, she was treated with chemotherapy, which resulted in excellent regression of the tumor mass by the end of 8 months follow-up. The patient was followed-up regularly with focal treatment whenever necessary. Two years later, she developed a massive recurrence necessitating enucleation. Histopathologic examination revealed a moderately differentiated retinoblastoma with choroidal invasion. Attempt to salvage the globe in adult onset retinoblastoma with chemoreduction and focal therapy may be possible; however, regular long-term follow-up is necessary for recurrence which warrants timely intervention.

INTRODUCTION

Adult onset retinoblastoma is a rare intraocular malignancy that has been previously reported in the literature.12 Many of the reported cases have been treated with enucleation due to the advanced nature of the disease. Focal therapy and chemotherapy have also been attempted, but with poor outcomes.34 Here we report a case of adult onset retinoblastoma, which initially responded very well to chemotherapy; however, massive recurrence of the tumor necessitated enucleation of the eye.

CASE REPORT

A 30-year-old female diagnosed elsewhere with choroidal melanoma with retinal detachment, presented to our emergency department with complaints of seeing black spot in front of the right eye accompanied with intermittent flashes for 20 days. On examination, the best-corrected visual acuity (BCVA) was 6/9 in the right eye and 6/5 in the left eye. Intraocular pressure measured with Goldmann applanation tonometry was 11 and 15 mmHg in the right and left eye, respectively. Anterior segment examination was unremarkable. Fundus examination of the left eye was within normal limits. Fundus examination of the right eye revealed a large endophytic yellowish white, well-demarcated mass, with surface vascularity, located in the temporal quadrant extending up to the macula along with the presence of multiple subretinal yellowish infiltrates inferiorly [Figure 1a]. There was overlying exudative retinal detachment involving the inferior portion of the retina reaching the macula. A provisional diagnosis of adult onset retinoblastoma with subretinal seeding and exudative retinal detachment was made. The patient underwent ocular ultrasound examination of the right eye which revealed a dome-shaped mass with homogenous internal structure, high surface reflectivity, and variable low to medium internal reflective echoes, with a basal circumference of 11.1 mm and height of 5.8 mm and the presence of an exudative detachment reaching up to the macula. Magnetic resonance imaging (MRI) of brain also revealed a retinoblastoma in the right eye with no evidence of extraocular or optic nerve invasion. The patient subsequently underwent six cycles of chemotherapy (carboplatin, vincristine, and etoposide) combined with transpupillary thermotherapy over a period of 6 months with regular monthly follow-up. After the third cycle, the tumor mass started showing excellent regression [Figure 1b]. As some residual activity was present at the end of six cycles, she underwent two more cycles of chemotherapy and by the end of 8 months, the tumor had regressed completely leaving a flat scar [Figure 1c]. The lesion was quiescent for a period of about 10 months. On follow-up, 10 months after the last treatment, BCVA was 6/9 in the right eye and fundus examination revealed a regressed tumor with the presence of multiple small new tumor foci in the periphery [Figure 1d] which were treated with laser using indirect ophthalmoscopy and transconjunctival cryotherapy. She also received three more cycles of chemotherapy. She was followed-up for a period of 2 years and in the event of new tumor foci [Figure 2a], she was given focal therapy (either transpupillary thermotherapy or cryotherapy) subsequently resulting in tumor regression [Figure 2b]. After 2 years, at a follow-up visit, the BCVA had decreased to 6/60 in the right eye and fundus examination revealed significant media haze due to massive vitreous seeding [Figure 2c] and the presence of complicated cataract along with a substantial increase in the tumor size [Figure 2d]. She was given the options of enucleation or lens sparing external beam radiotherapy. Patient was not willing to undergo enucleation initially. As the tumor showed further progression over the next 2-3 months, the patient was advised to undergo enucleation with ball implant with the aim of preventing further tumor spread and she agreed. Histopathologic examination of the enucleated globe revealed a moderately differentiated retinoblastoma with choroidal invasion of more than 3 mm and presence of tumor cells in the anterior fibers of the sclera. There was no evidence of optic nerve invasion. In view of choroidal invasion, she was advised 6 cycles of adjuvant chemotherapy; however, patient was not keen to undergo treatment and underwent just one cycle of chemotherapy and then discontinued treatment. On her last follow-up visit, 6 months later, the socket was healthy and the left eye remains normal.

Figure 1

Color fundus montage of the right eye showing. (a) Presence of a large endophytic lesion with surface vascularity and overlying exudative retinal detachment and numerous subretinal infiltrates inferiorly. (b) Significant resolution of the exudative retinal detachment with marked reduction in the tumor size, the vascularity and the inferior subretinal infiltrates following three cycles of chemotherapy. (c) Complete regression of the tumor resulting in a scar at the end of eight cycles of chemotherapy. (d) Presence of the scarred tumor along with small active tumor foci in the inferior and nasal periphery at 10-month follow-up after tumor regression

Figure 2

Color fundus photos of the right eye showing. (a) Presence of larger peripheral active tumors along the old inactive scarred tumors. (b) Regressed tumors with scarring following chemotherapy and focal therapy. (c) Significant media haze due to vitreous seeding and complicated cataract, with hazy view of the disc and the tumor. (d) Large tumor masses in inferior periphery with extensive surface vascularity and exudative retinal detachment

DISCUSSION

The reason why retinoblastoma occurs in adults remains unknown. Most of the cases reported are unilateral and sporadic. Presence of calcification on ultrasonography and computerised tomography (CT) scan is not mandatory for diagnosis of retinoblastoma in adults as seen in the present case and also in other reports.4 The behavior of adult onset retinoblastoma is very similar to the childhood disease. Enucleation is the primary modality of treatment in adults,15 mainly due to the large tumor size and the late presentation. Though there have been reports of spontaneous regression6 as well as tumors showing initial response when treated with brachytherapy and or cryotherapy, they may recur34 eventually leading to enucleation. What was unique to our case was that it showed excellent response initially and had near normal vision and then failed therapy with reactivation necessitating enucleation. Whether it is the genetic make-up of the adult onset retinoblastoma that makes it difficult to salvage the eye, can only be addressed with further studies.

CONCLUSION

Attempts to salvage the globe in adult onset retinoblastoma with chemoreduction and focal therapy may be possible; however, regular long-term follow-up is needed for potential recurrence, which mandate timely intervention.