Subject(s)
Breast Neoplasms , Biomarkers, Tumor , Humans , Medical Oncology , Pathologists , Receptor, ErbB-2ABSTRACT
AIMS: Spitz naevi are difficult to diagnose, because of significant overlap with melanomas. It has been recently demonstrated that the LSI RREB1(6p25)/LSI MYB(6q23)/LSI CCND1(11q13)/CEP6 fluorescence in-situ hybridization (FISH) assay is a reliable tool with which to distinguish benign naevi and melanomas. Little is known about its diagnostic usefulness in Spitz naevi. METHODS AND RESULTS: We investigated 51 patients with Spitz naevi and long-term median follow-up (8.18 years) with the multicolour FISH probe. Control groups included 11 benign naevi and 14 melanomas. Spitz naevi from 32 (63%) patients did not show cytogenetic abnormalities (FISH-). In contrast, Spitz naevi from 19 (37%) patients showed changes in the investigated loci (FISH+). Spitz naevi with the FISH+ profile showed chromosome X polysomy in 14/18 (78%) patients. All Spitz naevi with the FISH- profile were disomic. All melanomas displayed a FISH+ profile, and 4/11 (36%) showed chromosome X polysomy. No differences in clinicopathological features were detected between Spitz naevi with and without genetic abnormalities. CONCLUSIONS: The presence of gene copy number changes in Spitz naevi as detected by FISH is higher than expected, and Spitz naevi at the genetic level represent a heterogeneous group. The findings of similar cytogenetic alterations in Spitz naevi and melanomas suggest that there should be cautious interpretation of FISH analysis in this setting.
Subject(s)
Chromosome Aberrations , Chromosomes, Human, X , In Situ Hybridization, Fluorescence , Nevus, Epithelioid and Spindle Cell/diagnosis , Nevus, Epithelioid and Spindle Cell/genetics , Skin Neoplasms/diagnosis , Skin Neoplasms/genetics , Adolescent , Adult , Biopsy , Child , Child, Preschool , Cyclin D1/genetics , DNA-Binding Proteins/genetics , Diagnosis, Differential , Female , Follow-Up Studies , Gene Dosage/genetics , Humans , Male , Melanoma/diagnosis , Melanoma/genetics , Melanoma/pathology , Middle Aged , Nevus, Epithelioid and Spindle Cell/pathology , Oncogene Proteins v-myb/genetics , Retrospective Studies , Skin/pathology , Skin Neoplasms/pathology , Transcription Factors/genetics , Young AdultABSTRACT
Introduction. Gastrointestinal stromal tumors (GISTs) are characterized at the molecular level by c-kit or PDGFRA oncogene mutations. Although GISTs raised major interest in past decades, population-based studies are still rare. Materials and Methods. All GISTs diagnosed in Southern Switzerland (1999-2005) were identified using Ticino Cancer Registry and analysed for c-kit and PDGFRA mutations. Clinical and molecular features were studied. Results. Annual incidence of GISTs was 1.47 cases/100,000 inhabitants (median age: 64 years; median size: 6.0 cm). Most GISTs arose in the stomach (60.5%). The malignancy risk was very-low/low in 47% of patients. DNA sequences showed a gene alteration in either c-kit or PDGFRA genes in 72.5% of patients. Mutations occurred mostly in c-kit exon 11 (60%). No mutations in c-kit exons 13 or 17 were found. An equal number of alterations in exons 12 and 18, and no mutations in exon 14 were observed in the PDGFRA gene. Discussion. This is the first comprehensive population-based study of GISTs incidence and molecular biology characterization in Central Europe. Our incidence data showed higher age-standardized rates compared to other European countries. The gene mutation spectrum differed when compared to the literature. This is relevant to improve the molecular profile knowledge based on Cancer Registry data.