Cultivation of retinoblastoma cells: Correlation between in vitro growth pattern and histopathology

Purpose: To investigate the correlation between floating versus adherent growth pattern of cultivated retinoblastoma (RB) cells from three patients with RB and their histopathologic features. Methods: RB cells from three Iranian patients (MM, NR, and MS) were cultivated in Dulbecco's modified eagle medium (DMEM) supplemented with 15% fetal bovine serum (FBS) for four weeks in each passage. Fresh medium was added on a weekly basis and immunocytochemistry for Synaptophysin was performed. All experiments were performed in duplicate. Growth pattern of the cultivated RB cells was studied during the three consecutive passages and compared among three cases in the light of histopathologic data. Results: Cultivated RB cells from MM and NR demonstrated an adherent growth pattern in the 2 nd week and the pattern was enhanced by the 4 th week. The RB tumorspheres adhered to the bottom of the flask while surrounded by fibroblasts. Histopathologic diagnosis in MM and NR was a well-differentiated RB without optic nerve involvement. Such an adherent growth was not observed in cultivated RB cells from MS, in which the histopathologic analysis revealed a poorly-differentiated RB with optic nerve intrusion and prominent choroidal invasion. Conclusion: The adherent growth pattern of cultivated RB cells might be associated with tumor differentiation and the lack of optic nerve involvement in histopathology.