Melanotic Translocation Renal Cell Carcinoma With a Novel ARID1B-TFE3 Gene Fusion.

Abstract

A 36-year-old male was found to have a 7.0 cm left upper pole renal mass on renal ultrasound. Following nephrectomy, the mass was grossly ill-demarcated, friable and red-brown, invading renal parenchyma, hilar fat and the renal vein. Microscopically, the tumor had a nested and papillary architecture. The cells demonstrated abundant clear and eosinophilic cytoplasm and focal intracytoplasmic melanin pigment. Nucleoli were prominent. By immunohistochemistry, the tumor was positive for TFE3; HMB-45 stained approximately 5% of tumor cells corresponding to the histologic melanin pigment, which was confirmed with Fontana-Masson stain with bleach. Immunostains for PAX8, CD10, MiTF, and CAIX were negative; keratins Cam 5.2 and AE1/AE3 were focally positive. Targeted next-generation sequencing revealed an ARID1B-TFE3 gene fusion. Melanotic Xp11 renal cell carcinoma is a rare, pigment containing translocation variant demonstrating overlapping features with melanoma and is usually associated with an SFPQ-TFE3 gene fusion. The patient is alive and without evidence of disease 7 years after his diagnosis. The combination of high grade histopathology, the presence of melanin, absent PAX8, keratin positivity, and relatively indolent clinical behavior with a unique translocation may warrant recognition as a distinct renal cell carcinoma translocation subtype.

• Authors: Tatjana Antic, Jerome B Taxy, Mir Alikhan, Jeremy Segal
• Journal: The American journal of surgical pathology (Am J Surg Pathol) Vol. 41 Issue 11 Pg. 1576-1580 (Nov 2017) ISSN: 1532-0979 [Electronic] United States
• PMID: 28877054 (Publication Type: Case Reports, Journal Article)

Chemical References

• ARID1B protein, human
• Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
• Biomarkers, Tumor
• DNA-Binding Proteins
• Melanins
• PAX8 Transcription Factor
• PAX8 protein, human
• TFE3 protein, human
• Transcription Factors
• Keratins

Topics

• Adult
• Basic Helix-Loop-Helix Leucine Zipper Transcription Factors (analysis, genetics)
• Biomarkers, Tumor (analysis, genetics)
• Biopsy
• Carcinoma, Renal Cell (chemistry, genetics, pathology, surgery)
• Chromosomes, Human, X
• DNA-Binding Proteins (genetics)
• Gene Fusion
• Genetic Predisposition to Disease
• Humans
• Immunohistochemistry
• Keratins (analysis)
• Kidney Neoplasms (chemistry, genetics, pathology, surgery)
• Male
• Melanins (analysis)
• Neoplasm Grading
• Nephrectomy
• PAX8 Transcription Factor (analysis)
• Phenotype
• Sequence Analysis, DNA
• Transcription Factors (genetics)
• Translocation, Genetic