Incidence of pineal gland cyst and pineoblastoma in children with retinoblastoma during the chemoreduction era.

PURPOSE

To report on the frequency of cysts and tumors of the pineal gland in patients with retinoblastoma.

DESIGN

Observational retrospective case control study.

SETTING

Institutional. study population: Four hundred eight patients treated for retinoblastoma from January 2000 to January 2012 at Wills Eye Institute, Philadelphia, Pennsylvania, USA.

OBSERVATION PROCEDURE

Magnetic resonance imaging (MRI) features of the pineal gland were evaluated in all patients with retinoblastoma. Characteristics of patients with pineal cysts and pineoblastoma were reviewed.

MAIN OUTCOME MEASURES

Comparison of frequency of pineal gland cyst and pineoblastoma in children managed with systemic chemoreduction vs other methods.

RESULTS

Of 408 patients, treatment included systemic chemoreduction in 252 (62%) and nonchemoreduction methods in 156 (38%). Overall, 34 patients (8%) manifested pineal gland cyst and 4 (1%) showed pineoblastoma. Of all 408 patients, comparison (chemoreduction vs nonchemoreduction) revealed pineal cyst (20/252 vs 14/156, P = .7) and pineoblastoma (1/252 vs 3/156, P = .1). The pineal cyst (n = 34) (mean diameter 4 mm) was asymptomatic (n = 34), followed conservatively (n = 34), and with minimal enlargement (n = 2, 9%) but without progression to pineoblastoma. The cyst was found in 22 germline and 12 nongermline patients (P = .15). Among the 4 patients with pineoblastoma, all had germline mutation and 2 had family history of retinoblastoma. Among all patients with family history of retinoblastoma (n = 45), 2 (4%) developed pineoblastoma. The pineoblastoma was asymptomatic in 2 patients and symptomatic with vomiting and headache in 2 patients. The mean interval from date of retinoblastoma detection to pineal cyst was 2 months (median 2, range 0-8 months) and to pineoblastoma was 27 months (median 28, range 7-46 months). Management included aggressive chemotherapy and radiotherapy, with 2 survivors.

CONCLUSIONS

Pineal gland cyst was incidentally detected in 8% of retinoblastoma patients, causing no symptoms, and without progression to pineoblastoma. Pineoblastoma was detected in 1% of patients and fewer patients who received systemic chemotherapy developed pineoblastoma, possibly indicating a systemic protective effect.