[Retinoblastoma spontaneous regression: clinical and histopathologic analysis]

To analyze the clinicopathologic characteristics of retinoblastoma spontaneous regression.

Retrospective case series study. The clinic and pathologic data of 52 cases of retinoblastoma spontaneous regression were analyzed retrospectively. All the cases came from 579 cases of retinoblastoma (without pre-enucleation chemotherapy) archived in Ophthalmic Pathology Laboratory of Beijing Tongren Eye Centre from Jan. 2007 to Dec. 2013. The analyzed factors included tumor activity, tumor invasion, and tissue changes of uveal and lens.

In this study, the patients' average age was (14.0 ± 8.7) months. There were 33 (63.5%) male and 19 (36.5%) female patients. The rate of retinoblastoma spontaneous regression was 9.0% (52/579), of which the rate of complete regression was 1.4% (8/579). The most common symptom was leucocoria coupled with red eye 55.8% (29/52). The typical clinicopathologic characteristics were as follows: (1) all or most of all tumor cells suffered coagulation necrosis and only tumor cell remains were left; (2)most eyeballs showed atrophiabulbi or phthisis bulbi; (3) severe atrophy occurred in uvea, especially in iris and ciliary body combined with pigment cells disintegrating; (4) cataract formed coupled with lens swelling, displacement, or wrapped by fibrous connective tissue; (5) in a small number of cases, there were alive tumor cells in the retrolaminar optic nerve or choroid in spite of most tumor cells had suffered regression, indicating the patients had histopathologic high risk factors and had the dispositions of tumor diffusion and metastasis.

Some untypical clinical manifestation such as leukocoria coupled with red eye or atrophia bulbi should be paid close attention. The possibility of retinoblastoma spontaneous regression should be considered. Meanwhile, some cases of retinoblastoma spontaneous regression with histopathologic high risk factors should be given post-enucleation systemic adjuvant chemotherapy combined with close observations and follow-ups.