Expression of TFH Markers and Detection of RHOA p.G17V and IDH2 p.R172K/S Mutations in Cutaneous Localizations of Angioimmunoblastic T-Cell Lymphomas.
Am J Surg Pathol
; 41(12): 1581-1592, 2017 Dec.
Article
in En
| MEDLINE
| ID: mdl-28945625
ABSTRACT
Skin biopsies of 41 angioimmunoblastic T-cell lymphoma patients were retrospectively analyzed for the expression of follicular helper T-cell (TFH) markers, Epstein-Barr virus (EBV), and the presence of RHOA (p.G17V) and IDH2 (p.R172K/S) mutations using allele-specific polymerase chain reaction. We categorized cases into 4 distinctive patterns (1) low-density lymphocytic perivascular infiltrates (n=11), (2) dense perivascular infiltrates with atypical cells and occasional inflammatory cells (n=13), (3) diffuse infiltrates reminiscent of angioimmunoblastic T-cell lymphoma (n=4), or (4) other aspects (n=13). Two EBV and 2 plasmacytoid lymphoproliferative disorders were seen. We observed variable expression of TFH markers (CD10 [50%], BCLB6 [84%], PD1 [94%], CXCL13 [84%], and ICOS [97.5%]), and EBV B-blasts (26%). A TFH phenotype was identified in 82% and 73%, respectively, of cases with the most challenging patterns 1 and 2. TFH markers and EBV can thus help for diagnosis and are detected in samples with low-density infiltrates. We found RHOA G17V and IDH2 R172K/S mutations in the skin in 14/18 (78%) and 3/16 (19%) cases, respectively. The RHOA G17V mutation was identified in a proportion of biopsies with patterns 1 and 2, which represent a diagnostic challenge. The RHOA G17V mutation was detected both in the skin and lymph node (LN) biopsies in 7/9 (64%) cases, and in only the skin or the LN of 1 sample each. The frequency of RHOA G17V mutation was similar to that reported in LNs. It may represent a sensitive diagnostic marker in the skin, helpful in cases with low-density infiltrates.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Skin Neoplasms
/
Biomarkers, Tumor
/
Lymphoma, T-Cell, Cutaneous
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T-Lymphocytes, Helper-Inducer
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RhoA GTP-Binding Protein
/
Immunoblastic Lymphadenopathy
/
Isocitrate Dehydrogenase
/
Mutation
Type of study:
Diagnostic_studies
/
Prognostic_studies
Limits:
Humans
Language:
En
Journal:
Am J Surg Pathol
Year:
2017
Document type:
Article