[Post-radiation choroidal melanoma pathomorphosis assessment in clinical practice].

Objective: To study the pathomorphological changes in eyes that underwent secondary enucleation following various types of organ-preserving treatments for choroidal melanoma (CM).

Material and methods: The study included 22 enucleated eyes with CM. Secondary enucleation was performed between 2 and 120 months after isolated and combined brachytherapy with Ru-106 and Rh-106 radioisotopes, proton therapy, and Gamma Knife treatment. The reasons for enucleation included progressive tumor growth in 12 patients and complications in 10 patients. Pathomorphological examinations were conducted at the National Center for Clinical Morphological Diagnostics, Saint Petersburg.

Results: The majority of the enucleated eyes showed spindle-cell tumors with varying degrees of pigmentation, scleral invasion (95.5%), Bruch's membrane rupture (90.5%), peri- and intratumoral lymphocytic infiltration (85.7%), signs of perineural invasion (22.7%), and involvement of the optic nerve in the tumor process (28.6%). In the study group, signs of vascular invasion in the tumor parenchyma were observed in only 4.8% of the enucleated eyes. Therapeutic pathomorphosis was evaluated according to Mandard et al. (1994), where TRG4 (60.0%) was frequently diagnosed, and Becker et al. (2003), where TRG3 (65.0%) predominated. The mitotic activity ranged from 1.0 to 5.0 mitoses per 1 mm², with an average of 1.6±1.5.

Conclusions: The presence of viable tumor cells and their mitotic activity, regardless of the organ-preserving treatment, reflects the absence of the so-called "devitalization" of the tumor and determines the high risk of continued tumor growth and its possible metastasis.