Cutaneous Lymphomas

Abstract

Primary cutaneous T-cell lymphomas (CTCL) represent the majority of cutaneous lymphomas (CLs) and are a spectrum of diseases with a wide variety of clinical, histological, and phenotypic features and diverse biologic behavior. This review focuses on the observations on new variants of CTCL and recent developments in deciphering the pathogenetic mechanisms, which have implication for the nosologic concepts and future classification of CLs. Variants of mycosis fungoides (MF) such as the unilesional and the papular form have been characterized in more detail. Studies analyzed the expression of CD30 and PD-1 in MF and other forms of CTCL. New variants in the group of cutaneous CD30⁺ lymphoproliferative disorders include the epidermotropic CD8⁺ variant of lymphomatoid papulosis (type D) and angiocentric lymphomatoid papulosis (type E), which histologically mimic aggressive lymphomas, and therefore may be diagnostically challenging. Cutaneous proliferations of T cell-expressing markers of follicular helper T cells (PD-1, CXCL-13, and bcl-6) display a prognostically heterogeneous group. There is an increasing spectrum of CTCL with the expression of CD8 by tumor cells, including CD8⁺ MF, CD8⁺ forms of cutaneous CD30⁺ lymphoproliferative disorders, and CD8⁺ small/medium-sized lymphoproliferations, which are not included as distinct entities in the World Health Organization-European Organization for Research and Treatment of Cancer for CLs and the World Health Organization classification. Unusual presentations and incomplete phenotypes of blastic neoplasm of plasmacytoid dendritic cells are discussed. Clinicopathologic correlation is mandatory for the diagnosis of primary CLs. Analysis of genetic and epigenetic alterations in CLs revealed new diagnostic markers and putative targets for therapy of aggressive forms of CLs.

Galectin-3 Expression in Primary Cutaneous CD30-Positive Lymphoproliferative Disorders and Transformed Mycosis Fungoides

“…In all of these cases ALK (anaplastic lymphoma kinase) was negative. LYP cases were histologically subclassified as type A (36), type B (1) and type C (8) as described [1,2,13,14]. In 2 cases a mixed type of A and C was found.…”

“…Primary cutaneous CD30+ lymphoproliferative disorders (CD30 LPD) are the second most common form of cutaneous T-cell lymphoma [1,2]. By definition, cutaneous lymphoma is limited to the skin at the time of diagnosis.…”

Primary cutaneous lymphomas: diagnosis and treatment

“…The median age at diagnosis is 45 years. Histologically, lymphomatoid papulosis is divided into the following 4 subtypes [ 50 ]: type A characterized by large CD30+ atypical cells intermingled with a prominent inflammatory infiltrate consisting of histiocytes, small lymphocytes, granulocytes and eosinophils; type B characterized by epidermotropism and infiltration with smaller atypical cells with hyperchromatic cerebriform nuclei resembling atypical lymphocytes in MF, and of antigen composition of C-ALCL; type C characterized by sheets of CD30+ anaplastic large lymphocytes; type D characterised by infiltrates similar to those in CD8+ aggressive epidermotropic lymphoma or/and resembling pagetoid reticulosis (CD8+ CD30+, sometimes CD4+, CD56+). …”

Approach to cutaneous lymphoid infiltrates: When to consider lymphoma?

“…Progression of disease is characterized by development of plaques, tumors, erythroderma, blood, and/or visceral involvement. [ 17 18 19 20 ] Histopathologically, diagnostic biopsies of patch-stage MF are characterized by a psoriasiform and lichenoid infiltrate of lymphocytes with epidermotropism, cytologic atypia, and superficial dermal fibrosis [ Figure 3 ]. [ 21 22 23 24 25 26 27 ]…”

“…Both have a poor prognosis with early extracutaneous dissemination and death from disease progression. [ 1 18 61 62 63 64 65 66 67 68 69 ] In contrast, all forms of LyP affect younger patients and appear as waxing and waning papules/small nodules typically clustered in one or two body segments, with no risk of disease progression and an excellent prognosis. [ 70 71 72 73 74 75 76 77 ] Similar to LyP, PL affects young adults but tends to be disseminated to numerous body segments and display a self-limited course.…”