Folliculotropic T‐cell infiltrates associated with B‐cell chronic lymphocytic leukaemia or MALT lymphoma may reveal either true mycosis fungoides or pseudolymphomatous reaction: seven cases and review of the literature

Abstract

Folliculotropic T-cell infiltrates associated with B-cell malignancies can be either a true folliculotropic MF or a pseudo-MF. The distinction between both conditions cannot rely only on the histopathological aspect, but needs both a clinical pathological correlation and the search for a dominant T-cell clone. Whether the neoplastic T and B cells derive from a common ancestor or the T-cell proliferation is promoted by the underlying B-cell lymphoma remains unsolved, but interaction between B and T cell in the skin does not appear to be dependent on a TFH differentiation of the T-cell infiltrate.

T‐cell papulosis associated with B‐cell malignancy: a distinctive clinicopathologic entity

“…T‐cell lymphomas, myeloid malignancy). In particular, follicular papular and nodular lesions corresponding to folliculotropic mycosis fungoides (MF), according to common clinical, histological and molecular criteria, as previously reported were excluded.…”

Cutaneous, Purpuric Painful Nodules Upon Addition of Ibrutinib to RCVP Therapy in a CLL Patient: A Distinctive Reaction Pattern Reflecting Iatrogenic Th2 to Th1 Milieu Reversal

“…6 Other findings in a Th2 environment would be a shift in immunoglobulin makeup to favor higher levels of IgE by way of lymphocyte IL-4 7 and IL-13 8 production, and even IL-17a 9 production. As a result of this Th2 shift, cutaneous biopsies often show exuberant T-cell infiltrates including pseudolymphomatous arthropod bite reactions, 10,11 necrotizing eosinophilic folliculitis, 12 follicular mucinosis, 13 and more recently follicular mycosis fungoides. 14 A Th1-driven infiltrate, however, is represented by an IL-2, INF-g, and eventually TNF-a milieu, and consists of cytotoxic T cells, macrophages, and azurocidin-laden neutrophils.…”

Exacerbation of mycosis fungoides leading to the diagnosis of chronic myelomonocytic leukemia

“…Also, a “pseudo” MF could be discussed as reported in B-cell chronic lymphocytic leukemia. 12 , 13 It has been described as lesions clinically and histologically indistinguishable from MF, but without evidence of a positive T-cell receptor rearrangement. Yet, the long duration from diagnosis of MF to diagnosis of CMML and the typical histologic picture are in favor of a true cutaneous lymphoma in our case.…”