Diagnostic value of STMN1, LMO2, HGAL, AID expression and 1p36 chromosomal abnormalities in primary cutaneous B cell lymphomas

Evelyne Verdanet (1, 2, 3) , Olivier Dereure (1, 4, 2) , Céline René (1, 2, 5) , Ariane Tempier (1, 2, 3) , Assia Benammar-Hafidi (1, 2, 3) , Mathieu Gallo (1, 2, 3) , Eric Frouin (6) , Luc Durand (1, 3) , Isabelle Gazagne (1, 2, 7) , Valérie Costes-Martineau (1, 4, 3) , Valère Cacheux (1, 2, 7) , Vanessa Szablewski (1, 2, 3)

1 CHRU Montpellier - Centre Hospitalier Régional Universitaire [Montpellier]
2 UM - Université de Montpellier
3 Service de Biopathologie [CHRU Montpellier]
4 Pathogénèse et contrôle des infections chroniques (PCCI)
5 Cellules Souches, Plasticité Cellulaire, Médecine Régénératrice et Immunothérapies (IRMB)
6 CHU de Poitiers [La Milétrie] - Centre hospitalier universitaire de Poitiers = Poitiers University Hospital
7 Département Hématologie biologique [CHRU Montpellier]

Distinction between primary cutaneous follicular lymphoma (PCFL) and primary cutaneous marginal zone lymphoma (PCMZL) is challenging, as clear-cut immunophenotypical and cytogenetic criteria to segregate both entities are lacking. METHODS AND RESULTS: To characterize PCFL and PCMZL more clearly and to define criteria helpful for the differential diagnosis, we compared expression of immunohistochemical markers [LIM-only transcription factor 2 (LMO2), human germinal centre-associated lymphoma (HGAL), stathmin 1 (STMN1), activation-induced cytidine deaminase (AID), myeloid cell nuclear differentiation antigen (MNDA)] and the presence of cytogenetic abnormalities described previously in nodal follicular lymphoma [B cell lymphoma 2 (BCL2) and BCL6 breaks, 1p36 chromosomal region deletion (del 1p36)] in a series of 48 cutaneous follicular and marginal zone lymphomas [cutaneous follicular lymphoma (CFL) and cutaneous marginal zone lymphoma (CMZL)]. Immunostaining for STMN1, LMO2, HGAL and AID allowed the distinction between CFL and CMZL, and STMN1 was the most sensitive marker (100% CFL, 0% CMZL). LMO2, HGAL and AID were positive in 93.2%, 82.1% and 86.2% CFL (all CMZL-negative). MNDA was expressed in both entities without significant difference (10.3% CFL, 30.8% CMZL, P = 0.18). BCL2, BCL6 breaks and the del 1p36 were present in 16.7%, 10.7% and 18.5% CFL and no CMZL. Finally, three and 29 CFL were reclassified as secondary cutaneous follicular lymphomas (SCFL) and PCFL without significant differences concerning phenotypical and cytogenetic features. BCL2, BCL6 breaks and the del 1p36 were present in 11.1%, 8% and 16.7% PCFL and did not impact the prognosis. CONCLUSION: LMO2, HGAL, STMN1 and AID, but not MNDA, are discriminant for the recognition between CFL and CMZL. BCL2, BCL6 rearrangements and the del 1p36 have a role in the pathogenesis of PCFL, the latest being the most common alteration.

Mots clés: cytogenetic alteration; STMN1; 1p36 chromosomal deletion; cutaneous lymphoma

Domaines: Sciences du Vivant [q-bio]; Médecine humaine et pathologie

Evelyne Verdanet, Olivier Dereure, Céline René, Ariane Tempier, Assia Benammar-Hafidi, et al.. Diagnostic value of STMN1, LMO2, HGAL, AID expression and 1p36 chromosomal abnormalities in primary cutaneous B cell lymphomas. Histopathology, 2017, 71 (4), pp.648--660. ⟨10.1111/his.13279⟩. ⟨hal-01760832⟩