# A case report: identifying a novel variant in ELOC(TCEB1)-mutant renal cell carcinoma

## TL;DR

This case report describes a new mutation in the ELOC(TCEB1) gene found in a 48-year-old male with a specific type of kidney cancer, aiding in its diagnosis and understanding.

## Contribution

The study identifies a novel TCEB1 mutation (c.218T>A, p.V73E) in ELOC(TCEB1)-mutant renal cell carcinoma, previously unreported.

## Key findings

- The tumor exhibited clear cell morphology and expressed multiple markers including PAX8, CA9, and ELOC(TCEB1).
- The novel TCEB1 mutation was confirmed using next-generation and Sanger sequencing.
- The case expands the known mutation spectrum of ELOC(TCEB1)-RCC and supports the use of genetic testing for diagnosis.

## Abstract

ELOC(TCEB1)-mutant renal cell carcinoma [ELOC(TCEB1)-RCC] is a newly recognized type of RCC characterized by clear cell morphology and ELOC(TCEB1) gene mutation. We analyzed one case with a point mutation in TCEB1 c.218T>A (p.V73E), which is a novel mutation site and has not been reported in ELOC(TCEB1)-RCC. The case involved a male individual of age 48, whose computed tomography scan of the abdomen indicated the presence of a solid nodule located in the kidney. The tumor cells showed expression of PAX8, CA9, AMACR/P504S, Vimentin, CK7, CD10, FH, INI1(SMARCB1) and ELOC(TCEB1), and ELOC was mainly located in the nucleus. CD117, TFE3, HMB45, and SDHB were not express, and the expression rate of Ki67 was <5%. The novel variant in ELOC(TCEB1) gene was identified by the next-generation sequencing (NGS) test, subsequently also confirmed by Sanger sequencing. The ELOC(TCEB1) gene mutation testing is helpful for the diagnosis of this type of RCC. The case further expands our knowledge of the spectrum of TCEB1 gene mutation in ELOC(TCEB1)-RCC and enhances the optimization of clinical decision-making.