We present a cohort of 8 renal carcinomas that displayed a variable (5%-95% extent) light microscopic appearance of renal angiomyoadenomatous tumor/clear cell papillary renal cell carcinoma (RAT/CCPRCC) without fulfilling the criteria for these tumors. All but 1 case predominantly (75%-95% extent) showed histopathologic features of conventional clear cell renal cell carcinoma. In 5 of 7 cases with mostly conventional clear renal cell carcinoma (CRCC) morphology, a diagnosis of CRCC was supported by the molecular genetic findings (presence of von Hippel-Lindau tumor suppressor [VHL] mutation and/or VHL promoter methylation and/or loss of heterozygosity [LOH] for 3p). Of the other 2 cases with predominantly characteristic CRCC morphology, 1 tumor did not reveal any VHL mutation, VHL promoter methylation, or LOH for 3p, and both chromosomes 7 and 17 were disomic, whereas the other tumor displayed polysomy for chromosomes 7 and 17 and no VHL mutation, VHL promoter methylation, or LOH for 3p. One tumor was composed primarily (95%) of distinctly RAT/CCPRCC-like morphology, and this tumor harbored a VHL mutation and displayed polysomy for chromosomes 7 and 17. Of the 5 cases with both histomorphologic features and molecular genetic findings of CRCC, we detected significant immunoreactivity for alpha-methylacyl-CoA racemase in 2 cases and strong diffuse immunopositivity for cytokeratin 7 in 3 cases. Despite the combination of positivity for alpha-methylacyl-CoA racemase and cytokeratin 7 in 2 cases, there was nothing to suggest of the possibility of a conventional papillary renal cell carcinoma with a predominance of clear cells.
- MeSH
- Adenoma * diagnostic imaging MeSH
- Angiomyoma * diagnosis MeSH
- Chromosome Aberrations MeSH
- Diagnosis, Differential MeSH
- Adult MeSH
- Carcinoma, Renal Cell * diagnosis MeSH
- Keratin-7 metabolism MeSH
- Middle Aged MeSH
- Humans MeSH
- Chromosomes, Human, Pair 17 MeSH
- Chromosomes, Human, Pair 7 MeSH
- Neoplasms, Multiple Primary diagnosis MeSH
- Mutation MeSH
- Von Hippel-Lindau Tumor Suppressor Protein genetics MeSH
- Kidney Neoplasms * diagnosis MeSH
- Carcinoma, Papillary * diagnosis MeSH
- Racemases and Epimerases metabolism MeSH
- Aged MeSH
- von Hippel-Lindau Disease MeSH
- Loss of Heterozygosity MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
We present a series of a distinct tumorous entity named renal angiomyoadenomatous tumor (RAT). Five cases were retrieved from the consultation files of the authors. Histologic and immunohistochemical features were evaluated. Sequencing analysis of coding region of the VHL gene was carried out in all cases. The tumors were composed of admixture of an epithelial clear cell component and prominent leiomyomatous stroma. Epithelial cells formed adenomatous tubular formations endowed with blister-like apical snouts. All tubular/glandular structures were lined by a fine capillary network. The epithelial component was positive for epithelial membrane antigen, CK7, CK20, AE1-AE3, CAM5.2, and vimentin in all cases. In all analyzed samples, no mutation of the VHL gene was found. RAT is a distinct morphologic entity, being different morphologically, immunohistochemically, and genetically from all renal tumors including conventional clear cell carcinoma and mixed epithelial and stromal tumor of kidney.
- MeSH
- Adenoma chemically induced metabolism pathology MeSH
- Biomarkers metabolism MeSH
- Epithelial Cells pathology MeSH
- Financing, Organized MeSH
- Keratin-20 metabolism MeSH
- Keratin-7 metabolism MeSH
- Keratins metabolism MeSH
- Middle Aged MeSH
- Humans MeSH
- Mucin-1 metabolism MeSH
- Mutation MeSH
- Von Hippel-Lindau Tumor Suppressor Protein genetics MeSH
- Kidney Neoplasms genetics metabolism pathology MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Vimentin metabolism MeSH
- Loss of Heterozygosity MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Case Reports MeSH
