Diagnostic Value of Genotypic Analysis in Primary Cutaneous Lymphomas using Standardized BIOMED-2 Polymerase Chain Reaction Protocols: Experience in Daily Clinical Practice.

BIOMED-2 Concerted Action BMH4-CT98-3936 (BIOMED-2) PCR protocols are an important diagnostic tool in the evaluation of cutaneous lymphomas. The aim of this study was to assess the diagnostic value of the genotyping results obtained by these techniques in daily clinical practice. A total of 360 paraffin-embedded skin samples were retrospectively reviewed from 114 cutaneous T-cell lymphomas and 35 cutaneous B-cell lym-phomas. A total of 249 biopsies from 180 patients with benign lymphoid infiltrates served as controls. T-cell receptor and immunoglobulin gene rearrangements were assessed using the BIOMED-2 method. A combined T-cell receptor gamma and beta assay approach reliably distinguished cutaneous T-cell lymphomas from benign skin T-cell infiltrates (sensitivity 89.4%; specificity 81.5%). Analysis of complete immunoglobulin heavy chain rearrangements also differentiated cutaneous B-cell lymphomas from benign B-cell infiltrates (sensitivity 85.7%; specificity 82.4%). In conclusion, the full BIOMED-2 protocol is a useful aid combined with clinical, histological and immunophenotypical findings for assessment of lymphoid clonality in skin lymphoid proliferations.

Multi-center evaluation of the novel fully-automated PCR-based Idylla™ BRAF Mutation Test on formalin-fixed paraffin-embedded tissue of malignant melanoma.

The advent of BRAF-targeted therapies led to increased survival in patients with metastatic melanomas harboring a BRAF V600 mutation (implicated in 46-48% of malignant melanomas). The Idylla(™) System (Idylla(™)), i.e., the real-time-PCR-based Idylla(™) BRAF Mutation Test performed on the fully-automated Idylla(™) platform, enables detection of the most frequent BRAF V600 mutations (V600E/E2/D, V600K/R/M) in tumor material within approximately 90 min and with 1% detection limit. Idylla(™) performance was determined in a multi-center study by analyzing BRAF mutational status of 148 archival formalin-fixed paraffin-embedded (FFPE) tumor samples from malignant melanoma patients, and comparing Idylla(™) results with assessments made by commercial or in-house routine diagnostic methods. Of the 148 samples analyzed, Idylla(™) initially recorded 7 insufficient DNA input calls and 15 results discordant with routine method results. Further analysis learned that the quality of 8 samples was insufficient for Idylla(™) testing, 1 sample had an invalid routine test result, and Idylla(™) results were confirmed in 10 samples. Hence, Idylla(™) identified all mutations present, including 7 not identified by routine methods. Idylla(™) enables fully automated BRAF V600 testing directly on FFPE tumor tissue with increased sensitivity, ease-of-use, and much shorter turnaround time compared to existing diagnostic tests, making it a tool for rapid, simple and highly reliable analysis of therapeutically relevant BRAF mutations, in particular for diagnostic units without molecular expertise and infrastructure.