Pagetoid reticulosis tumor cells with double expression of TCRγδ and TCRαβ: an off-target phenomenon or genuine expression?

Woringer-Kolopp disease (localized pagetoid reticulosis): a systematic review

OBJECTIVE

Woringer-Kolopp disease (WKD), also known as localized pagetoid reticulosis, is a rare variant of mycosis fungoides as described by the World Health Organization-European Organization for Research and Treatment of Cancer (WHO-EORTC) classification system for cutaneous lymphomas. Our objective was to conduct a comprehensive review that describes and evaluates patient demographics, clinical presentation, immunohistochemical findings, management, and outcomes of WKD.

METHODS

The databases PubMed, Embase, and Cochrane Library were searched for relevant literature. Patient demographics, imaging, treatments, and other clinical characteristics were obtained. The literature search was conducted on December 7, 2020. Studies were included if they contained primary data related to WKD. Non-pertinent studies, non-English studies, non-human studies, review articles, or studies with insufficient case information were excluded. The quality of the included studies and the risk of bias were evaluated using the Grades of Recommendation, Assessment, Development, and Evaluation Group (GRADE) criteria (2016), Oxford Centre for Evidence-Based Medicine: Levels of Evidence (OCEBM) (March 2009), and the Methodological Index for Non-Randomized Studies (MINORS) criteria (2003).

RESULTS

A total of 84 studies with 143 patients met the inclusion criteria for this study. The most common chief complaint was an asymptomatic, slow-growing, and erythematous plaque. The average time from initial skin eruption to presentation was 97.6 months. Histologically, 128 cases of WKD displayed epidermotropism (97.7%). Various therapies, including radiotherapy, surgery, and local chemotherapy, were used. In total, 92 (78.6%) cases had complete remission and 11 (9.4%) cases recurred.

CONCLUSIONS

WKD is a rare cutaneous T-cell lymphoma that often presents as a single plaque on the extremities with an indolent course and a favorable prognosis. However, it is often misdiagnosed, leading to delays in treatment. The diagnosis of WKD involves clinical appraisal, a biopsy of suspicious lesions, and immunohistochemistry. Monotherapy appears to be preferred compared to combination therapy for WKD with radiotherapy demonstrating among the highest cure rates and lowest recurrence. Future retrospective and prospective studies are needed to accurately determine the epidemiology, prognosis, and effective treatments for WKD. Limitations include a possibility of missed studies, heterogeneity in reporting methods, publication, and selection bias.

Gamma/Delta (γδ) T Cells: The Role of the T-Cell Receptor in Diagnosis and Prognosis of Hematologic Malignancies

ABSTRACT

There are 2 types of T cells: αβ and γδ T cells, named based on the composition of the T-cell receptor. γδ T cells are rare, making up 0.5%-10% of T cells. Although most leukemias, lymphomas, and immune-mediated conditions derive from αβ T cells, a handful of rare but important diseases are generally derived from γδ T cells, particularly primary cutaneous γδ T-cell lymphoma, hepatosplenic T-cell lymphoma, and monomorphic epitheliotropic intestinal T-cell lymphoma. There are also malignancies that may evince a γδ TCR phenotype, including large granulocytic lymphocyte leukemia, T-cell acute lymphobplastic leukemia (T-ALL), and mycosis fungoides, although such cases are rare. In this article, we will review the genesis of the T-cell receptor, the role of γδ T cells, and the importance of TCR type and methods of detection and outline the evidence for prognostic significance (or lack thereof) in lymphomas of γδ T cells. We will also highlight conditions that rarely may present with a γδ TCR phenotype and assess the utility of testing for TCR type in these diseases.

The significance of epidermal involvement in primary cutaneous gamma/delta (γδ) T-cell lymphoma: A systematic review and meta-analysis

BACKGROUND

Primary cutaneous gamma/delta (γδ) T-cell lymphoma (PCGDTCL) is a rare, aggressive peripheral T-cell lymphoma. There is evidence that patients with epidermotropic PCGDTCL may have an improved prognosis compared with those with only dermal and/or subcutaneous involvement.

METHODS

Systematic review of the literature and application of inclusion criteria yielded 48 manuscripts detailing the cases of 104 patients.

RESULTS

Of the 104 patients, 57 were male (51.4%) and 47 were female (48.5%) Based on provided histopathologic descriptions, 57 cases (54.8%) had no epidermotropism, 47 cases (45.2%) patients demonstrated any degree of epidermotropism, and 25 cases were predominantly epidermotropic (25/104, 24%). Five-year overall survivals for patients with no epidermotropism, any epidermotropism, and predominantly epidermotropic presentation were 32.8%, 28.9%, and 40.0%, respectively (p = 0.40). The most commonly performed immunohistochemical markers were CD3, CD4, CD8, CD5, CD7, CD30, CD56, TCR beta, TCR γ, and TCR δ. There was no statistically significant difference in immunophenotype between groups. Lesion morphology was described in the majority of cases (85/104, 80.9%); most cases presented as a combination of nodules, plaques, and tumors (77.4%). Several cases had more atypical presentations, including "mycosis-fungoides-like" and ulcerated.

CONCLUSION

In PCGDTCL, neither epidermotropism nor predominantly epidermotropic phenotype predict a better prognosis. In addition, the case report literature in dermatology and dermatopathology is rich and highly valuable.

Primary Cutaneous T-Cell Lymphomas Showing Gamma-Delta (γδ) Phenotype and Predominantly Epidermotropic Pattern are Clinicopathologically Distinct From Classic Primary Cutaneous γδ T-Cell Lymphomas

Primary cutaneous gamma-delta (γδ) T-cell lymphoma is a rare disease that typically involves the dermis and subcutis. Cases of primary cutaneous T-cell lymphomas showing γδ phenotype and predominantly epidermotropic pattern (EγδTCL) are not well defined. In this series, cases of primary cutaneous T-cell lymphomas showing γδ phenotype were reviewed and classified as predominantly epidermotropic (EγδTCL) when >75% of lymphoma cells resided in the epidermis or predominantly dermal and/or subcutaneous (DSγδTCL). Clinical, pathologic, and immunophenotypic features were compared in 27 biopsies from 13 patients of EγδTCL and 13 biopsies from 7 patients of DSγδTCL. The lymphoma cells were diffusely positive for CD3 and T-cell receptor (TCR)γ, mostly positive for granzyme B and TIA-1, variably positive for CD8, CD7, and CD30, and negative for CD4 and TCRβ. Two patients with EγδTCL had dissemination to lymph nodes and 1 to the lung; 1 patient with DSγδTCL had gastrointestinal involvement. The median survival of patients with EγδTCL was not reached, and with a median follow-up of 19.2 months, 3/13 died. In contrast, the median survival of patients with DSγδTCL was 10 months, and after a median follow-up of 15.6 months, 5/5 died (P<0.01). EγδTCL is a rare presentation of cutaneous T-cell lymphoma that can be distinguished from DSγδTCL based on the extent of epidermotropism and has a better prognosis and longer median survival than DSγδTCL. However, although EγδTCL resembles mycosis fungoides clinically and histologically, a subset of EγδTCL is more likely to behave more aggressively than typical mycosis fungoides.

Cutaneous Lymphomas with Cytotoxic Phenotype

Primary cutaneous cytotoxic lymphomas are T-cell or natural killer-cell lymphomas that express 1 or more cytotoxic markers. These neoplasms constitute a spectrum of diseases. In this review, an overview of clinical, morphologic, and phenotypical features of each subtype is provided. Differential diagnosis is discussed with attention to scenarios in which diagnostic difficulties are most frequently encountered.

Cutaneous CD8+ Cytotoxic T-Cell Lymphoma Infiltrates: Clinicopathological Correlation and Outcome of 35 Cases

Introduction

Cytotoxic CD8+ T-cell lymphomas are only rarely encountered and thus remain only poorly characterized. Our aim was to collect and correlate clinical and histological data of CD8+ skin lymphoma infiltrates to obtain a proper subtype assignment of CD8+ skin lymphoma infiltrates and to derive putative prognostic markers thereof.

Methods

Formalin-fixed and paraffin-embedded (FFPE) tissue of 35 patients with CD8+ cytotoxic cutaneous T-cell lymphoma infiltrates was retrieved from the archives of the Institute of Pathology and the Department of Dermatology, University Hospital Wuerzburg, dating back from 1998 until 2015. Cytological, histological, immunohistochemical and molecular genetic features were assessed and correlated with respective clinical data.

Results

The identified cases of CD8+ cytotoxic atypical lymphoproliferative infiltrates of the skin (n = 35) comprised 13 cases of mycosis fungoides (MF)/Sézary syndrome (SS), 4 cases of subcutaneous panniculitis-like T-cell lymphoma (SPTCL), 5 cases of primary cutaneous acral CD8+ lymphoma [formerly indolent CD8+ lymphoid proliferation (ILP)] and 1 case of aggressive epidermotropic primary cutaneous T-cell lymphoma (AECTCL). Moreover, nine cases were classified as primary cutaneous peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) and three cases as systemic PTCL-NOS. Multiple skin lesions, a high proliferative index and especially a final subtype attribution to AECTCL or systemic PTCL-NOS were associated with a worse survival. Coexpression of CD68 by tumor cells was exclusively observed in indolent acral CD8+ T-cell lymphoma and thus indicated an invariably benign clinical course. No further distinctive markers could be derived from our analysis.

Conclusion

Cutaneous infiltrates of CD8+ cytotoxic T-cell lymphoma comprise clinically and histologically heterogeneous entities of either primary cutaneous T-cell lymphomas or secondary infiltrates of otherwise systemic peripheral T-cell lymphomas. A thorough clinicopathological correlation with respective staging examinations remains the mainstay for correct subtype assignment and proper prognostication as long as no better markers have been defined.

Pagetoid Reticulosis: Report of Two Cases and Review of the Literature

Pagetoid reticulosis is a rare variant of mycosis fungoides that presents with a large, usually single, erythematous, slowly growing scaly plaque containing an intraepidermal proliferation of neoplastic T lymphocytes. Histopathologically, this disease has distinctive attributes. In this report, we present two cases of pagetoid reticulosis, compare its microscopic features to those of ‘classical’ mycosis fungoides, and provide a brief review of the pertinent literature.