Primary cutaneous aggressive epidermotropic cytotoxic T-cell lymphomas: reappraisal of a provisional entity in the 2016 WHO classification of cutaneous lymphomas.

Primary cutaneous CD8-positive aggressive epidermotropic T-cell lymphoma is a rare and poorly characterized variant of cutaneous lymphoma still considered a provisional entity in the latest 2016 World Health Organization Classification of Cutaneous lymphomas. We sought to better characterize and provide diagnostic and therapeutic guidance of this rare cutaneous lymphoma. Thirty-four patients with a median age of 77 years (range 19-89 years) presented primarily with extensive annular necrotic plaques or tumor lesions with frequent mucous membrane involvement. The 5-year survival was 32% with a median survival of 12 months. A subset of 17 patients had a prodrome of chronic patches prior to the development of aggressive ulcerative lesions. We identified cases with lack of CD8 or αβ T-cell receptor expression yet with similar clinical and pathological presentation. Allogeneic stem cell transplantation provided partial or complete remissions in 5/6 patients. We recommend the term primary cutaneous aggressive epidermotropic cytotoxic T-cell lymphoma as this more broad designation better describes this clinical-pathologic presentation, which allows the inclusion of cases with CD8 negative and/or αβ/γδ T-cell receptor chain double-positive or double-negative expression. We have identified early skin signs of chronic patch/plaque lesions that are often misdiagnosed as eczema, psoriasis, or mycosis fungoides. Our experience confirms the poor prognosis of this entity and highlights the inefficacy of our standard therapies with the exception of allogeneic stem cell transplantation in selected cases

Authors reply to the letter to editor with regard to the article titled “Sézary syndrome and mycosis fungoides: An overview, including the role of immunophenotyping”

We have read with interest the letter to editor by M. Roelens et al. in response to our article on Sézary syndrome (SS) and mycosis fungoides (MF) and the role of immunophenotyping for diagnosis. We appreciate their comments on the potential utility of CD158k (KIR3DL2) for the diagnosis of SS and MF, which certainly complement the data on SS immunophenotyping we report. The authors cite their published work about the role of CD158k for the precise identification of Sézary cells (SCs). Based on their observations, they recommend introducing KIR3DL2/CD158k as a positive marker for the accurate identification of SCs using flow cytometry (Roelens, de Masson, Ram-Wolff, Bagot, & Moins-Teisserenc, 2020). We agree that CD158k is a promising marker, particularly because it would allow “positive” selection of SCs (instead of focusing on downregulated molecules, such as CD7 and CD26) while being negative in normal residual CD4+ T cells, as stated by Roelens et al. However, it should be noted that unequivocal expression of CD158k on SCs from most SS cases has been reported only by this group (though consistently over a long time), using an antibody obtained from a therapeutic antibody manufacturer and not commercially available as a flow-cytometry reagent. Unfortunately, other authors could not reproduce these results using the same clones and fluorochrome (Boonk et al., 2016, and personal observations), possibly due to issues with the reagent, such as lot-to-lot variability and stability for a product that most likely does not currently meet the quality standards to be sold as an analyte specific reagent (ASR) or even a research use only (RUO) antibody. Therefore, to definitively establish the precise utility of CD158k for SS (and MF) immunophenotyping in a standardized way, the exact antibody products used by M. Roelens et al (i.e., clone AZ158k or more recently clone 13E4, both conjugated to phycoerythrin, provided by Innate Pharma, Marseille, France) should be used and offered as a standard quality flow cytometry product (i.e., guaranteeing lot-to-lot stability, effective and stable dye-to-antibody ratio, etc.) available for purchase. This would allow different groups of experts to reach reproducible and comparable results, before recommending the systematic inclusion of CD158k in consensus/standardized panels for SS/MF immunophenotyping

Sézary syndrome and mycosis fungoides: An overview, including the role of immunophenotyping

This review discusses the definition and major categories of cutaneous T‐cell lymphoma, Sézary syndrome and mycosis fungoides, and the role of immunophenotyping in their diagnosis. The following key points are raised: (a) Sézary syndrome and mycosis fungoides cells most often have a characteristic CD3+ CD4+ CD7− and/or CD26− immunophenotype. (b) This immunophenotype is not specific, but can assist in the distinction from non‐neoplastic T cells and other subtypes of mature T‐cell neoplasm. (c) However, small subsets of normal and reactive T‐cells can have an overlapping immunophenotype, and can be distinguished by evaluating for additional changes in antigen expression.Peer reviewe

Jejunal adenocarcinoma with cutaneous metastasis

Small bowel adenocarcinoma (SBA) is a rare primary gastrointestinal malignancy. We present a 60-year old man who developed a cutaneous metastasis of jejunal adenocarcinoma to his neck. This case highlights the clinicopathologic and immunophenotypic features of this uncommon cutaneous metastasis

Jejunal adenocarcinoma with cutaneous metastasis

Small bowel adenocarcinoma (SBA) is a rare primary gastrointestinal malignancy. We present a 60-year old man who developed a cutaneous metastasis of jejunal adenocarcinoma to his neck. This case highlights the clinicopathologic and immunophenotypic features of this uncommon cutaneous metastasis