Abstract
Purpose: :
To determine whether there is any relationship between Gene Expression Profiling (GEP) classification and cytopathologic diagnosis of melanocytic uveal tumors sampled by fine needle aspiration biopsy (FNAB).
Methods: :
Samples from 44 melanocytic uveal tumors were obtained by FNAB. In each case, at least 2 samples were obtained and evaluated cytopathologically for melanocytic cell type and by GEP for the presence of the Class 1 (favorable) versus Class 2 (unfavorable) signature. The relationship between GEP and cytopathologic classification of tumor cells was evaluated by cross tabulation analysis.
Results: :
The cytopathologic diagnosis was melanocytic nevus in 1 case, borderline melanocytic uveal tumor in 4 cases, spindle cell melanoma in 10 cases, mixed cell melanoma in 8 cases, epithelioid cell and/or necrotic melanoma in 12 cases, and uveal melanoma of unspecified cell type in 3 cases. Six of the 44 tumors (13.6%) yielded an insufficient specimen for cytodiagnosis even though they had been sampled in 2 or more sites. In contrast, FNAB yielded a sufficient specimen for GEP in all 44 cases. Twenty five cases (56.8%) were categorized as Class 1 and 19 (43.2%) were categorized as Class 2. The cytodiagnosis for Class 1 tumors was epithelioid cell and/or necrotic melanoma in 6 cases, mixed cell or unspecified melanoma in 5, insufficient for diagnosis in 5, spindle cell melanoma in 5, borderline in 3, and nevus in 1 case. The cytodiagnosis for Class 2 tumors was epithelioid cell and/or necrotic melanoma in 6 cases, mixed cell or unspecified melanoma in 6, spindle cell melanoma in 5, borderline in 1, and insufficient for diagnosis in 1 case. The cytodiagnosis was non-melanoma or indeterminate in 9 Class 1 tumors and 2 Class 2 tumors, and it was definite melanoma in 16 Class 1 tumors and 17 Class 2 tumors. This difference did not reach statistical significance (P = 0.081, Fisher exact test).
Keywords: melanoma • gene/expression • oncology