Güncel Patoloji Dergisi
2026, Cilt 10, Sayı 1
Evaluation of BRAF Gene Mutations in Renal Tubulopapillary Tumors
1 Ege Üniversitesi Tıp Fakültesi, Tıbbi Patoloji Anabilim Dalı, İzmir, Türkiye
2 İzmir Şehir Hastanesi, Tıbbi Patoloji Laboratuvarı, İzmir, Türkiye
3 Ege Üniversitesi Tıp Fakültesi, Üroloji Anabilim Dalı, İzmir, Türkiye
DOI : 10.5146/jcpath.2026.681 Aim: Despite increasing research on the molecular alterations in renal cell carcinoma subtypes, tumors with tubulopapillary morphology have not yet been sufficiently characterized. Previous studies have suggested that the Ras/Raf pathway may play a crucial role in renal cell carcinoma tumorigenesis. Several studies investigating BRAF mutations in malignant renal tubulopapillary tumors have been published. Material and Methods: In this study, tubulopapillary tumors were analyzed for BRAF mutations to determine the role of this molecular alteration in tumor pathogenesis. Sixty-three renal tumors with predominant tubulopapillary architecture wereevaluated using both pyrosequencing and immunohistochemistry. Results: According to renal tumor classification systems, 15 tumors (23.8%) were nephroblastomas, 13 (20.6%) were papillary renal cell carcinomas, 11 (17.5%) were mucinous tubular and spindle cell carcinomas, four (6.3%) were metanephric adenomas, and three (4.8%) were metanephric stromal tumors. Four metanephric adenomas (4/4) and one metanephric stromal tumor (1/3) demonstrated BRAF V600E mutations by pyrosequencing. All of these tumors were also positive by immunohistochemistry, although two showed weak staining. No BRAF mutations were detected in malignant tubulopapillary renal tumors. Except for metanephric tumors, our results support the absence of a relationship between tubulopapillary morphology and BRAF mutations. Conclusion: These findings provide novel insights into the pathobiology of tubulopapillary renal tumors, as the study includes mucinous tubular and spindle cell carcinoma and clear cell papillary renal cell tumor, which have been rarely investigated in the literature. Larger molecular studies are needed to further characterize the molecular profile of renal tumors and to facilitate the development of targeted therapies. Anahtar Kelimeler : BRAF V600E, BRAF VE1, Metanephric adenoma, Renal cell carcinoma, Nephroblastoma
2 İzmir Şehir Hastanesi, Tıbbi Patoloji Laboratuvarı, İzmir, Türkiye
3 Ege Üniversitesi Tıp Fakültesi, Üroloji Anabilim Dalı, İzmir, Türkiye
DOI : 10.5146/jcpath.2026.681 Aim: Despite increasing research on the molecular alterations in renal cell carcinoma subtypes, tumors with tubulopapillary morphology have not yet been sufficiently characterized. Previous studies have suggested that the Ras/Raf pathway may play a crucial role in renal cell carcinoma tumorigenesis. Several studies investigating BRAF mutations in malignant renal tubulopapillary tumors have been published. Material and Methods: In this study, tubulopapillary tumors were analyzed for BRAF mutations to determine the role of this molecular alteration in tumor pathogenesis. Sixty-three renal tumors with predominant tubulopapillary architecture wereevaluated using both pyrosequencing and immunohistochemistry. Results: According to renal tumor classification systems, 15 tumors (23.8%) were nephroblastomas, 13 (20.6%) were papillary renal cell carcinomas, 11 (17.5%) were mucinous tubular and spindle cell carcinomas, four (6.3%) were metanephric adenomas, and three (4.8%) were metanephric stromal tumors. Four metanephric adenomas (4/4) and one metanephric stromal tumor (1/3) demonstrated BRAF V600E mutations by pyrosequencing. All of these tumors were also positive by immunohistochemistry, although two showed weak staining. No BRAF mutations were detected in malignant tubulopapillary renal tumors. Except for metanephric tumors, our results support the absence of a relationship between tubulopapillary morphology and BRAF mutations. Conclusion: These findings provide novel insights into the pathobiology of tubulopapillary renal tumors, as the study includes mucinous tubular and spindle cell carcinoma and clear cell papillary renal cell tumor, which have been rarely investigated in the literature. Larger molecular studies are needed to further characterize the molecular profile of renal tumors and to facilitate the development of targeted therapies. Anahtar Kelimeler : BRAF V600E, BRAF VE1, Metanephric adenoma, Renal cell carcinoma, Nephroblastoma