A retrospective study of 18 children with subcutaneous panniculitis-like T-cell lymphoma: multidrug combination chemotherapy or immunomodulatory therapy?

Characteristics and therapeutic outcomes of subcutaneous panniculitis-like T-cell lymphoma with and without germline HAVCR2 mutations in Thai children and adolescents

BACKGROUND

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare subtype of non-Hodgkin lymphoma associated with hemophagocytic lymphohistiocytosis (HLH)/HLH-like systemic illnesses and germline HAVCR2 mutations. Although previous studies suggested successful treatment of SPTCL with immunosuppressive therapy (IST) without chemotherapy, IST data in pediatric SPTCL remain scarce. To explore characteristics and therapeutic outcomes, comparing IST-based and chemotherapy-based regimens in pediatric SPTCL, in this retrospective cohort study, patients with SPTCL diagnosed at age ≤20 years during 2007-2023 were enrolled from 6 hematology/oncology centers in Thailand. HAVCR2 exon 2 sequencing was performed using DNA extracted from peripheral blood or bone marrow. Presence of HLH/HLH-like systemic illnesses, treatment outcomes, and adverse events (AEs) were reviewed and analyzed.

RESULTS

Of 22 patients with SPTCL (median age at diagnosis, 11.5 years [range, 6.0-19.0]; 63.6% males), 86.4% harbored germline HAVCR2 mutation, either homozygous (77.3%) or heterozygous (9.1%) p.Y82C variant, while 68.2% developed HLH/HLH-like systemic illnesses. Overall, 36.4% received IST as first-line treatment. Durable complete remission (CR) was achieved in 71.4% and 50.0% after first-line chemotherapy and IST, respectively (P=0.45); however, chemotherapy tended to increase any AEs compared to IST (57.1% vs. 12.5%; P=0.07). The most common AEs were hypertension (27.3%), febrile neutropenia (18.2%), and fungal infection (13.6%). Among the relapsed cases, 71.4% could reach CR after subsequent-line therapy. Fatality (4.5%) only occurred in the chemotherapy group.

CONCLUSIONS

Pediatric SPTCL in Thailand frequently involves germline HAVCR2 mutations and/or HLH/HLH-like systemic illnesses. With comparable response and modest therapy-related toxicity, IST-based regimens may alternatively be considered as first-line treatment for pediatric SPTCL.

Ruxolitinib Monotherapy for a Child With HAVCR2 Gene Mutation Associated Subcutaneous Panniculitis-like T-cell Lymphoma: A Case Report

BACKGROUND

The occurrence of hemophagocytic lymphohistiocytosis (HLH) in patients with subcutaneous panniculitis-like T-cell lymphoma (SPTCL) may be due to HAVCR2 gene mutation, leading to T-cell immunoglobulin and mucin domain-containing molecule 3 deficiency, T-cell and macrophage activation, and proinflammatory cytokine production.

OBSERVATION

We report a patient with SPTCL and HLH for whom ruxolitinib, used as a novel treatment, showed notable therapeutic effects.

CONCLUSIONS

Remission of both HAVCR2 mutation-induced high inflammatory characteristics and significant symptoms post-ruxolitinib administration suggested that patients with SPTCL and HLH may not represent typical lymphoma cases. Ruxolitinib, with its relatively low toxic side effects, can provide favorable outcomes.

Subcutaneous panniculitis-like T-cell lymphoma: fever and facial swelling with hemophagocytic syndrome

We report a case of subcutaneous panniculitis-like T-cell lymphoma (SPTCL) in a young man presenting with fever and facial swelling. He had pancytopenia and hemophagocytic syndrome (HPS) on evaluation. The histopathological examination of skin punch biopsy from the face and chest wall showed SPTCL. Given the associated HPS, he was started on steroid and multidrug chemotherapy following which he had symptomatic improvement.

JAK Inhibitors in Cutaneous T-Cell Lymphoma: Friend or Foe? A Systematic Review of the Published Literature

Cutaneous T-cell lymphomas (CTCLs) are a group of lymphoid neoplasms with high relapse rates and no curative treatment other than allogeneic stem cell transplantation (allo-SCT). CTCL is significantly influenced by disruption of JAK/STAT signaling. Therefore, Janus kinase (JAK) inhibitors may be promising for CTCL treatment. This study is a systematic review aiming to investigate the role of JAK inhibitors in the treatment of CTCL, including their efficacy and safety. Out of 438 initially searched articles, we present 13 eligible ones. The overall response rate (ORR) in the treatment with JAK inhibitors in clinical trials was 11-35%, although different subtypes of CTCL showed different ORRs. Mycosis fungoides showed an ORR of 14-45%, while subcutaneous-panniculitis-like T-cell lymphoma (SPTCL) displayed an ORR ranging from 75% to 100%. Five cases were reported having a relapse/incident of CTCL after using JAK inhibitors; of these, three cases were de novo CTCLs in patients under treatment with a JAK inhibitor due to refractory arthritis, and two cases were relapsed disease after graft-versus-host disease treatment following allo-SCT. In conclusion, using JAK inhibitors for CTCL treatment seems promising with acceptable side effects, especially in patients with SPTCL. Some biomarkers, like pS6, showed an association with better responses. Caution should be taken when treating patients with an underlying autoimmune disease and prior immunosuppression.

Diagnosis and management of cutaneous lymphomas and lymphoid proliferations in children, adolescents and young adults (CAYA)

Cutaneous lymphomas and lymphoid proliferations (LPD) in children, adolescents, and young adults (CAYA) are a heterogeneous group of lymphoid neoplasms that present formidable diagnostic challenges to clinicians and pathologists alike. Although rare overall, cutaneous lymphomas/LPD occur in real-world settings and awareness of the differential diagnosis, potential complications, and various therapeutic approaches will help ensure the optimal diagnostic work-up and clinical management. Lymphomas/LPD involving the skin can occur as primary cutaneous disease in a patient that characteristically has lymphoma/LPD confined to the skin, or as secondary involvement in patients with systemic disease. This review will comprehensively summarize both primary cutaneous lymphomas/LPD that occur in the CAYA population as well as those CAYA systemic lymphomas/LPD with propensity for secondary cutaneous involvement. Focus on the most common primary entities occurring in CAYA will include lymphomatoid papulosis, primary cutaneous anaplastic large cell lymphoma, mycosis fungoides, subcutaneous panniculitis-like T-cell lymphoma, and hydroa vacciniforme lymphoproliferative disorder.