EORTC/USCLC/ISCL consensus recommendations for management and treatment of cutaneous lymphoproliferative disorders.

Background: In recent classifications several cutaneous lymphomas were reclassified as lymphoproliferative disorder (LPD). These include primary cutaneous CD4-positive small/medium T-cell LPD (PCSM-TCLPD), primary cutaneous acral CD8+ T-cell LPD (acral CD8+ TLPD) and primary cutaneous marginal zone LPD (PCMZLPD; still classified as primary cutaneous marginal zone lymphoma (PCMZL) in the 5th edition of the WHO classification). The results of a survey among 30 cutaneous lymphoma centres on the effects of this new terminology on clinical management revealed considerable heterogeneity and emphasized the need to develop uniform recommendations for management and treatment of these disorders.

Primary Cutaneous Anaplastic Large Cell Lymphoma With TCR-γδ Expression: A Case Series of Eleven Patients of a Rare Immunophenotypic Variant.

Background: Primary cutaneous anaplastic large cell lymphoma (pcALCL) and lymphomatoid papulosis (LyP) are indolent CD30-positive lymphoproliferative disorders that rarely express TCR-γδ. However, primary cutaneous gamma-delta T-cell lymphoma (pcGDTCL), characterized by TCR-γδ expression on neoplastic cells, is a rare, aggressive cutaneous T-cell lymphoma with a poor prognosis. Accurate differentiation is essential due to distinct clinical behavior and treatment.

Histologic and Immunohistochemical Patterns in Lymphomatoid Papulosis: A Systematic Review of Published Cases.

Based on histologic and genetic patterns, the current World Health Organization (WHO) classification distinguishes six subtypes of lymphomatoid papulosis (Lyp). The aim of our article was to analyze the frequency of histologic and immunohistochemical features of different Lyp subtypes reported in the literature. We used PubMed advanced search builder to systematically review and evaluate English and German literature of Lyp from 1968 to April 2022.

Problems when diagnosing cutaneous leishmaniasis: a retrospective study analyzing clinical, histopathological and immunohistochemical features.

Background: Cutaneous leishmaniasis (CL) incidence in Switzerland is rising due to factors like migration and globalization. The aim of this work was to investigate CL frequency in Switzerland and identify clinical and histopathological difficulties in diagnosing CL in a non-endemic country.

Patients And Methods: This retrospective study evaluated the clinical and histopathological characteristics of all CL cases from two dermatopathology laboratories between 2000 and 2022.

Subcellular expression of CD30 in cutaneous mastocytosis-An important factor for targeted treatment.

Background: The subcellular distribution of CD30 on mast cells and the presence of eosinophils in cutaneous mastocytosis require further investigation, especially as the cell surface expression of CD30 is critical for the therapeutic response of systemic mastocytosis to brentuximab vedotin.

Objective: Investigation of 147 biopsy specimens from 143 patients with cutaneous mastocytosis for mast cell density and distribution, frequency of CD30 expression, CD30 staining patterns, and presence and distribution of eosinophils. Correlation with clinical patterns.

Cutaneous Reactions after COVID-19 Vaccines: Analysis of the Clinical and Histopathological Spectrum-Case Series and Review of the Literature.

(1) Background: Various cutaneous adverse drug reactions (ADRs) are observed with the implementation of mRNA COVID-19 vaccines. To gain insight into the clinicopathologic features, we analyzed the correlation of histological and clinical data in 48 patients with these ADRs. (2) Methods: Single-center retrospective study in patients with ADRs after mRNA COVID-19 vaccination (mRNA-1273 and BNT162b2 vaccines).

Chilblain-Like Eruption Unveiling Cutaneous Aleukemic Relapse of Acute Myeloid Leukemia.

Leukemia cutis corresponds to skin infiltration by malignant hematopoietic cells. It is most commonly reported in acute myeloid leukemia, particularly in subtypes with a monocytic component. Its clinical manifestations are extremely variable, and histopathologic diagnosis of cutaneous leukemic infiltrates may be challenging.

Clinical, histopathological and molecular features of dedifferentiated melanomas: An EORTC Melanoma Group Retrospective Analysis.

Purpose: Dedifferentiated melanoma (DedM) poses significant diagnostic challenges. We aimed to investigate the clinical, histopathological and molecular features of DedM. Methylation signature (MS) and copy number profiling (CNP) were carried out in a subgroup of cases.

QuPath Analysis for CD30+ Cutaneous T-Cell Lymphoma.

Background: Mycosis fungoides is the most common subtype of cutaneous T-cell lymphoma, in which the expression of cluster of differentiation 30 (CD30)+ subtype can now be treated with the CD30 antibody conjugate brentuximab vedotin. Diagnostic methods are based on immunohistochemical (IHC) staining followed by manual assessment by pathologists, which is always a subjective calculation. QuPath, an open-source software for digital pathology image analysis, satisfies the requirements of objective approaches.

Intraindividual variability of CD30 expression in mycosis fungoides -implications for diagnostic evaluation and therapy.

Aims: To evaluate the frequency, subcellular localization, and variability of CD30 expression in mycosis fungoides.

Methods: This retrospective multicenter study investigated 135 biopsy specimens of 95 patients with mycosis fungoides for CD30 expression and CD30 staining pattern in relation to histomorphologic criteria, eosinophils, and tumour stage. We used two different CD30 cutoffs: (i) any CD30 positivity (important for in-label treatment with an anti-CD30 antibody-based drug), and (ii) ≥10% (most commonly used cutoff in therapy studies).