Uveal melanoma: An analysis of cellular features and comparison to monosomy 3 status

Diagn Cytopathol. 2016 May;44(5):377-83. doi: 10.1002/dc.23450. Epub 2016 Feb 15.

Abstract

Background: Choroidal and ciliary body melanomas divide into two approximately equal groups. Local therapy cures one group while the other metastasizes and proves lethal. Monosomy 3 strongly associates with aggressive behavior. We analyzed a series of choroidal and ciliary body melanomas to describe the cellular features and to compare them to monosomy 3 status using the latter as a surrogate for survival.

Methods: One hundred eleven specimens met the study's inclusion criteria. Following ThinPrep processing, samples were analyzed for cellular features including: cell type, nuclear grade, tumor infiltrating lymphocytes, and the presence of necrosis and melanin. FISH analysis for monosomy 3 was performed on ThinPrep slides using a threshold of 20% monosomic cells per 200 melanoma cells.

Results: Seventy-two tumors (65%) had a mixed cell type while spindle cell type and epithelioid cell type occurred in 37 (33%) and 2 (1.8%), respectively. Seventy-five tumors (68%) had Grade 2 nuclear atypia. Monosomy 3 occurred in 57 tumors (51%). Significantly more tumors with Grade 3 nuclei had monosomy 3 (79% vs.43%, P = 0.002) and metastases (29% vs. 8%, P = 0.01). None of the 11 pure spindle cell tumors with Grade 1 nuclei metastasized or had monosomy 3.

Conclusions: Uveal melanoma has a relatively consistent cellular appearance, characterized by a mixed cell pattern and no more than moderate nuclear atypia. This consistent appearance aids in the cellular diagnosis but limits prognostication using cellular features. Cellular features significantly associate with monosomy 3 status only in the minority of tumors at the extremes of the morphologic spectrum.

Keywords: choroidal melanoma; ciliary melanoma; eye cytology; monosomy 3; uveal melanoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Choroid Neoplasms / genetics
  • Choroid Neoplasms / pathology*
  • Chromosomes, Human, Pair 3 / genetics*
  • Ciliary Body / pathology
  • Humans
  • Melanoma / genetics
  • Melanoma / pathology*
  • Monosomy*
  • Neoplasm Metastasis