Test Catalog

Test ID: TFEBF    
Renal Cell Carcinoma, 6p21.1 (TFEB) Rearrangement, FISH, Tissue

Useful For Suggests clinical disorders or settings where the test may be helpful

Identifying TFEB gene rearrangements in patients with renal cell carcinoma (RCC)

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

This test does not include a pathology consult. If a pathology consultation is requested, PATHC / Pathology Consultation should be ordered and the appropriate FISH test will be ordered and performed at an additional charge.

 

This test includes a charge for application of the first probe set (2 FISH probes) and professional interpretation of results.

 

Additional charges will be incurred for all reflex probes performed. Analysis charges will be incurred based on the number of cells analyzed per probe set. If no cells are available for analysis, no analysis charges will be incurred.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

The TFEB gene may be altered in some patients with renal cell carcinoma (RCC). Identification of rearrangement of the TFEB gene region by FISH analysis can aid in the diagnosis of RCC.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided.

Interpretation Provides information to assist in interpretation of the test results

A positive result with the TFEB probe is detected when the percent of cells with an abnormality exceeds the normal cutoff for the probe set. A positive result of TFEB suggests promotor substitution caused by structural alterations of the TFEB gene region at 6p21.1. A negative result suggests no structural alterations of the locus.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

This test is not approved by the FDA and should be used as an adjunct to existing clinical and pathologic information.

 

Fixatives other than formalin (eg, Prefer, Bouin) may not be successful for FISH assays. Although FISH testing will not be rejected due to nonformalin fixation, results may be compromised.

 

Paraffin-embedded tissues that have been decalcified are generally unsuccessful for FISH analysis. The pathologist reviewing the hematoxylin and eosin-stained slide may find it necessary to cancel testing.

Supportive Data

FISH analysis was performed on 27 formalin-fixed paraffin-embedded specimens including 25 renal cell carcinoma (RCC) tissue samples, 2 RCC specimens from Johns Hopkins known positive for TFEB rearrangement, and 25 noncancerous control specimens. The normal controls were used to generate the normal cutoff values. Structural alterations resulting in the rearrangement of the TFEB gene region were identified and results correlated with pathology findings.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Argani P, Yonescu R, Morsberger L, et al: Molecular confirmation of t(6:11)(p21;q12) renal cell carcinoma in archival paraffin-embedded material using a break-apart TFEB FISH assay expands its clinicopathologic spectrum. Am J Surg Pathol 2012 Oct;36(10):1516-1526

2. Argani P, Cheville J, Ladanyi M: MiT family translocation renal cell carcinomas. In WHO Classifications of Tumours of Urinary System and Male Genital Organs. Fourth edition. Edited by H Moch, PA Humphrey, TM Ulbright, VE Reuter VE. Lyon, France, IARC Press, 2016, 33-34