Objective: To define the value of silver-stained nucleolar organizer regions (AgNOR) in the evaluation of uveal malignant melanomas (MM).
Study design: Morphometric analysis of AgNORs was performed on 30 uveal MM of spindle A, B, epithelioid and mixed cell types. Findings were compared with cytotype, largest tumor dimension (LTD) and clinical outcome.
Results: AgNOR mean perimeter (MP) was 3.76 microns (SD 1.21, range 1.79-8.51 microns) in A, 5.05 microns (SD 1.96, range 1.79-16.41 microns) in B and 6.15 microns (SD 3.86, range 1.79-33.80 microns) in epithelioid MM; mean area (MA) was 0.86 micron 2 (SD 0.60, range 0.20-2.78 microns 2) in A, 1.58 microns 2 (SD 1.11, range 0.20-9.63 microns 2) in B and 2.34 microns 2 (SD 2.10, range 0.20-15.27 microns 2) in epithelioid MM; the aspect ratio (AR) was 3.10 (SD 0.19, range 2.90-3.35) in A, 5.80 (SD 2.07, range 3.77-9.32) in B and 12.22 (SD 2.84, range 8.11-15.81) in epithelioid MM. From comparing MA and RA with follow-up, it seemed that MM with a good prognosis (spindle A and a subgroup of B tumors, B1) exhibited the lowest MA and AR values, while MM with poorer clinical behavior (epithelioid and a second subgroup of spindle B MM, B2) showed the highest. No correlation was found between AgNORs and LTD.
Conclusion: AgNORs may contribute to the prognostic evaluation of uveal MM.