Diagnosis and Treatment of Subcutaneous Panniculitis-like T-cell Lymphoma: A Systematic Literature Review

Treatment outcomes between cyclosporin and chemotherapy in adult subcutaneous panniculitis-like T-cell lymphoma: a report from nation-wide Thai lymphoma study group registry

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare subtype of T-cell lymphomas with a characteristic feature of subcutaneous nodules associated with hemophagocytic lymphohistiocytosis (HLH). Treatment options for SPTCL are mainly chemotherapy (CMT) or immunosuppressive agents with selection currently dependent on physician decisions. Outcomes between the 2 treatment remedies have not yet been comprehensively compared. This study aimed to compare complete remission (CR) rates between SPTCL patients receiving cyclosporin (CSA)-based regimen (CSA +/- steroid) and CMT. The 5-year overall survival (OS) and 5-year progression free survival (PFS) were also analyzed. Clinical data from patients with SPTCL were drawn from the Thai Lymphoma Study Group registry who were newly diagnosed between 2007 and 2023. A total of 93 patients were selected with 45 cases having received CSA-based regimen and 48 cases having received CMT. There were more patients with limited stage at skin in the CSA group (63.8% vs. 36.2%, p = 0.003), while more patients with hepato- and/or splenomegaly were found in the CMT group (56.2% vs. 24.5%; p = 0.002). Germline HAVCR2 mutations were detected in 26/33 (78.8%) cases. The CR rate was significantly higher in patients treated with CSA (87% vs. 58.3%; OR = 6.5 [95%CI, 2.7-15.3]; p = 0.002). At a median follow-up of 87.8 months (range 0-185), the 5-year OS (98% vs. 87%, p = 0.19) and PFS (72.4% vs. 69.2%, p = 0.19) showed a trend favoring patients treated with CSA. Based on our study, CSA-based regimens are the preferred first-line treatment remedy for newly diagnosed SPTCL, especially in patients with limited cutaneous involvement.

Blastic plasmacytoid dendritic cell neoplasm in an adolescent female: a rare entity with challenging diagnosis and management

Blastic plasmacytoid dendritic cell neoplasm is a rare and aggressive haematopoietic neoplasm with poor prognosis. It usually presents with cutaneous lesions and symptoms secondary to bone marrow involvement. Due to rarity and lack of standard treatment protocols, these cases are difficult to diagnose and treat. We report a case of a female in early adolescence who presented with skin nodules on the leg. The diagnosis was established by immunophenotypic studies. We discuss the investigations and treatment options available to diagnose and treat this malignancy.

Critical Role of Flow Cytometric Immunophenotyping in the Diagnosis, Subtyping, and Staging of T-Cell/NK-Cell Non-Hodgkin's Lymphoma in Real-World Practice: A Study of 232 Cases From a Tertiary Cancer Center in India

Background

T-cell/NK-cell non-Hodgkin’s lymphoma (T/NK-NHL) is an uncommon heterogeneous group of diseases. The current classification of T/NK-NHL is mainly based on histopathology and immunohistochemistry. In practice, however, the lack of unique histopathological patterns, overlapping cytomorphology, immunophenotypic complexity, inadequate panels, and diverse clinical presentations pose a great challenge. Flow cytometric immunophenotyping (FCI) is a gold standard for the diagnosis, subtyping, and monitoring of many hematological neoplasms. However, studies emphasizing the role of FCI in the diagnosis and staging of T/NK-NHL in real-world practice are scarce.

Methods

We included T-cell non-Hodgkin’s lymphoma (T-NHL) patients evaluated for the diagnosis and/or staging of T/NK-NHL using FCI between 2014 and 2020. We studied the utility of FCI in the diagnosis and subtyping of T/NK-NHL and correlated the FCI findings with the results of histopathology/immunohistochemistry. For correlation purposes, patients were categorized under definitive diagnosis and subtyping, inadequate subtyping, inadequate diagnosis, and misdiagnosis based on the findings of each technique.

Results

A total of 232 patients were diagnosed with T/NK-NHL. FCI findings provided definitive diagnoses in 198 patients and subtyping in 187/198 (95.45%) patients. The correlation between FCI and histopathological/immunohistochemistry results (n = 150) demonstrated an agreement on the diagnosis and subtyping in 69/150 (46%) patients. Of the remaining cases, the diagnosis and subtyping were inadequate in 64/150 (42.7%), and 14/150 (9.33%) were misdiagnosed on histopathology/immunohistochemistry results. FCI provided definitive diagnosis and subtyping in 51/64 (79.7%) patients. Among these, 13 patients diagnosed with peripheral T-cell lymphoma not-otherwise-specified were reclassified (angioimmunoblastic T-cell lymphoma (AITL)-11 and prolymphocytic leukemia-2) on FCI. It corrected the diagnosis in 14 patients that were misdiagnosed (6 B-cell NHL (B-NHL), 3 Hodgkin’s lymphoma, 1 acute leukemia, and 1 subcutaneous panniculitis-like T-cell lymphoma) and misclassified (3 T-NHL) on histopathological results. AITL was the commonest T-NHL misclassified on histopathological results. FCI also confirmed the definite involvement in 7/83 (8.4%) and 27/83 (32.5%) bone marrow (BM) samples reported as suspicious and uninvolved, respectively, on histopathological evaluation.

Conclusion

AITL was the most frequently diagnosed T/NK-NHL in this study. FCI provided a distinct advantage in detecting BM involvement by T/NK-NHL, especially in patients with low-level involvement. Overall, our study concluded that FCI plays a critical role in the diagnosis, subtyping, and staging of T/NK-NHL in real-world practice.

Primary cutaneous CD8+ cytotoxic T-cell lymphoma of the face with intraoral involvement, presenting facial nerve palsy after chemotherapy

The primary cutaneous (PC) CD8+ T-cell lymphoproliferative disorders (LPDs) comprise clinically and histologically heterogeneous entities including mycosis fungoides, lymphomatoid papulosis, hydroa-vacciniforme-like LPD, subcutaneous panniculitis-like T-cell lymphoma (TCL), PC acral CD8+ TCL, PC CD8+ aggressive epidermotropic cytotoxic TCL, and PC peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS). We describe a 33-year-old man who presented progressive facial swelling and lower lip involvement one year ago. Microscopy revealed an atypical small to medium-sized lymphoid proliferation exhibiting perivascular accentuation, adnexotropism and apoptotic cell debris, without surface epithelium involvement. The tumor cells were positive for CD3, CD8, granzyme B, perforin, MUM1/IRF4, and TCR-BF1. The Ki-67 labeling index was 48%. EBER1/2 was negative. Additional studies confirmed localized disease. The diagnosis favored PC-PTCL-NOS. Two months after completing chemotherapy, right-sided facial nerve palsy was diagnosed. CD8+ T-cell LPDs should be considered in the differential diagnosis when assessing facial swelling with intraoral involvement. This article is protected by copyright. All rights reserved.

Immune-Mediated Cutaneous Paraneoplastic Syndromes Associated With Hematologic Malignancies: Skin as a Mirror of Hematologic Neoplasms

Malignant neoplasms may present as paraneoplastic syndromes with mucocutaneous manifestations, which may or may not be chronologically associated. The pathophysiological mechanism is complex and not completely understood; therefore, definitive diagnosis may be achieved with a precise differential diagnosis based on the morphology of skin lesions, clinical picture, and histological pattern. The complexities, and low frequency, make the therapeutic approach quite challenging; consequently, the cornerstone of therapy is the eradication of the underlying neoplasms. Corticosteroids are the therapy of choice for most of these immune-mediated manifestations, but for the most part, the successful resolution requires the eradication of the underlying malignancy.