Granulomatous Processes and Clonality: PCR Evaluation of T-Cell Rearrangement for Diagnosis

Analysis of T-cell clonality is useful for differentiating sarcoidosis and primary granuloma annulare from granulomatous CTCLs.


Cutaneous T-cell lymphoma (CTCL), mycosis fungoides (MF) type, is the most common lymphoma of the skin, and the granulomatous variant is one of many histologic presentations. Granulomatous CTCLs often resemble primary granuloma annulare (GA) or sarcoidosis, so additional diagnostic tools may be needed to distinguish between these diseases. These authors evaluated the use of alpha beta T-cell gene rearrangement by polymerase chain reaction (PCR) in the work-up of sarcoidosis, GA, and granulomatous MF.

The authors examined samples from 35 cases of sarcoidosis, 15 cases of GA, and 19 cases of granulomatous CTCL for the presence of clonality using automated, high-resolution PCR fragment analysis. Pseudoclonality was eliminated by repeating clonality analysis in duplicate. T-cell clonality was found in none of the sarcoidosis cases and in only two of the GA cases. In contrast, nearly all of the granulomatous CTCLs had a neoplastic T-cell clone.


Citation(s):

Pfaltz K et al. Clonality in sarcoidosis, granuloma annulare, and granulomatous mycosis fungoides. Am J Dermatopathol 2011 Oct; 33:659.