Proof-of-Concept Evaluation of T-Cell Receptor Beta Constant Region 1 and 2 Transcript in Situ Hybridization for Clonality Assessment in Mycosis Fungoides.

Authors

Vrinda Madan, Jonathan Lai, Sima Rozati, Suman Paul, Jaroslaw Jedrych

Published in

Journal of cutaneous pathology. Oct 15, 2026. Epub Oct 15, 2026.

Abstract

Mycosis fungoides (MF) may be difficult to distinguish from inflammatory dermatoses. T-cell receptor (TCR) gene rearrangement assays provide ancillary evidence of clonality but lack spatial resolution. We evaluated the feasibility of RNA in situ hybridization (RNA-ISH) targeting TCR beta constant isoforms, TRBC1 and TRBC2, in routine skin biopsies.
We retrospectively analyzed 15 MF biopsies, predominantly Stage IA-IB, and 11 inflammatory controls using TRBC1 and TRBC2 RNA-ISH on separate sections. Expression was assessed semiquantitatively in matched intraepidermal regions using exploratory thresholds. Available TCR gamma PCR results were reviewed.
RNA-ISH was successful in all 26 samples. Nine MF cases (60%) showed TRBC skewing, three (20%) were indeterminate, and three (20%) were double negative. All controls showed balanced polytypic expression. Exploratory sensitivity was 60% (95% CI, 32.3%-83.7%) and specificity 100% (95% CI, 71.5%-100%). Substantial discordance with available PCR results was observed.
TRBC1/TRBC2 RNA-ISH is technically feasible in archival skin and can demonstrate spatial isoform skewing in a subset of MF biopsies. Technical and interpretive limitations preclude diagnostic validation; larger multiplexed studies are warranted.

PMID:
42881119
Bibliographic data and abstract were imported from PubMed on 16 Oct 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.