Phthisis bulbi in retinoblastoma

Abstract

Phthisis bulbi is a relatively uncommon and atypical clinical presentation of retinoblastoma. Retrospective study conducted at a tertiary care hospital. Eighteen consecutive retinoblastoma patients with primary phthisis bulbi. Retrospective analysis of clinical, imaging and histopathological features of all retinoblastoma patients with primary phthisis bulbi, treated at our centre between January 2005 and December 2009. Clinical and histopathology features. Eighteen (3.5%) retinoblastoma patients developed primary phthisis bulbi. The median age of presentation was 1.5 years. The median duration of symptoms before presentation was 6 months. In total, 15 out of 18 (83%) cases had bilateral disease. Among these, 80% (12/15) had advanced intraocular disease in the fellow eye. Most common first symptom was white reflex. History of orbital inflammation was present in 12/18 cases. Computed tomographic scan of orbit showed intraocular mass with calcific densities in 16 eyes. In two cases, hyperdense mass was seen without any calcification. On histopathology, residual viable tumour cells with characteristics of poorly differentiated retinoblastoma were found in 67% (12/18) eyes. High-risk factors were present in six cases with microscopic residual disease in three cases. This is the largest case series of retinoblastoma patients with primary phthisis bulbi. Phthisis bulbi in retinoblastoma may be associated with bilateral disease in most cases and advanced intraocular disease in the fellow eye in a significant number of cases. Regression is incomplete in majority of these cases; therefore, enucleation must definitely be done in all cases of retinoblastoma presenting with phthisis bulbi.