CASE OF THE WEEK
Editor: Mahmut Akgul (akgulm@amc.edu)
2022-11/March 14
Contributors: Ayush C. Srivastava MD, Varsha Manucha MD
60-year-old-female was found to have an incidental left renal and adrenal mass on imaging.
Quiz
1. What is the correct diagnosis?
a) Tubulocystic renal cell carcinoma
b)Papillary renal cell carcinoma
c)Fumarate hydratase-deficient renal cell carcinoma
d)Oncocytoma with tubulocystic pattern
e)Cystic nephroma
1. a
Tubulocystic renal cell carcinoma
Originally described as a low-grade collecting duct carcinoma, tubulocystic renal cell carcinoma (TC-RCC) was recently recognized as a distinct clinicopathologic entity and included in the WHO classification. TC-RCC is a rare tumor with <1% incidence and predominantly affecting male patients. The majority of the reported TC-RCC have shown indolent behavior, mostly presenting as pT1 disease, and with metastasis in < 10%.
The hallmark feature of TC-RCC is exclusive tubulocystic architecture creating a spongy, “bubble-wrap” gross appearance. Histologically the tubules are lined by a single layer of cuboidal/columnar and hobnailed cells with eosinophilic cytoplasm and prominent nucleoli. The stroma is fibrous and without desmoplasia. The immunoprofile and frequent trisomy of chromosome 17 in TC-RCC overlaps with papillary renal cell carcinoma (PRCC). However, TC-RCC also shows recurrent losses of chromosome 9 and Y, down-regulation of miR-155 and miR-34a, and mutations of ABL1 and PDGFRA genes, distinct from PRCC and other renal carcinoma subtypes.
Since tubulocystic growth pattern can be encountered in other renal neoplasms, TC-RCC should be diagnosedonly when present as a “pure” form, using well defined strict morphological criteria; presence of papillary, poorly differentiated, solid, nested, or rhabdoid patterns should exclude a tumor from diagnostic assignment of tubulocystic renal cell carcinoma. The adrenal mass was an incidental nerve sheath tumor.
Tran T, Jones CL, Williamson SR, Eble JN, Grignon DJ, Zhang S, Wang M, Baldridge LA, Wang L, Montironi R, Scarpelli M, Tan PH, Simper NB, Comperat E, Cheng L. Tubulocystic renal cell carcinoma is an entity that is immunohistochemically and genetically distinct from papillary renal cell carcinoma. Histopathology. 2016 May; 68(6):850-7. doi: 10.1111/his.12840. Epub 2015 Oct 21. PMID: 26310887.
Lawrie CH, Armesto M, Fernandez-Mercado M, Arestín M, Manterola L, Goicoechea I, Larrea E, Caffarel MM, Araujo AM, Sole C, Sperga M, Alvarado-Cabrero I, Michal M, HesO, López JI. Noncoding RNA Expression and Targeted Next-Generation Sequencing Distinguish Tubulocystic Renal Cell Carcinoma (TC-RCC) from Other Renal Neoplasms. J Mol Diagn. 2018 Jan;20(1):34-45. doi: 10.1016/j.jmoldx.2017.09.002. Epub 2017 Oct 19. PMID:29056573.
Ayush C. Srivastava MD (@ayush_acs), Varsha Manucha MD (@VarshaManuchaMD)
University of Mississippi Medical Center (@UMMC_pathology), Jackson, MS
Kidney
tubulocystic, eosinophilic, renal cell carcinoma