Pediatric subcutaneous panniculitis-like T-cell lymphoma with favorable result by immunosuppressive therapy: a report of two cases

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

BACKGROUND

Subcutaneous panniculitis T-cell lymphoma (SPTCL) is a rare, cytotoxic T-cell lymphoma with which some patients have accompanying hemophagocytic syndrome (HPS). There is currently no standard treatment regimen. In the past, the most commonly used treatment was multidrug chemotherapy. In contrast, numerous case reports or small series suggest that immunosuppressive drugs could also be effective for some patients. Since this NHL subtype is extremely rare in children and adolescents, to improve the understanding of this disease and standardize its rational treatment, we retrospectively summarized the treatment regimens of 18 pathologically diagnosed children with SPTCL to compare the clinical efficacy of multidrug chemotherapy and immunomodulatory therapy.

RESULTS

The median age of onset was 11.1 years. Painless subcutaneous nodules or skin patchy lesions were found in all patients, most commonly involving the lower extremities and/or trunk. Before January 1, 2019, the treatment was mainly chemotherapy, and 10 patients were initially treated with chemotherapy, among whom was one patient who progressed during initial treatment, was voluntarily discharged and was subsequently lost to follow-up, one patient who died of disease progression, and the remaining 8 patients who all achieved sustained remission, with a complete remission (CR) rate of 80% (8/10). Corticosteroids combined with cyclosporine A or ruxolitinib were the most common initial immunosuppressive agents at our center after January 1, 2019 and had a CR rate of 71.4% (5/7). In addition, 1 patient achieved partial remission (PR) during follow-up, and one had autologous hematopoietic stem cell transplantation (AHSCT) after 4 months of drug withdrawal. There were 7 patients (38.9%, one case in chemotherapy group and six cases in immunotherapy group) with HPS and 4/5 screened patients (80%) with positive HAVCR2 gene mutations. The median follow-up was 17 months.

CONCLUSION

The prognosis of SPTCL is relatively good. Previous multi-drug and long-term chemotherapy treatment has clear efficacy, and recent immunomodulatory therapy as pre-chemotherapy therapy can also benefit patients.

Hematopoietic stem cell transplantation for subcutaneous panniculitis-like T-cell lymphoma: single center experience in an Asian population

Subcutaneous panniculitis-like T-cell lymphoma (SPTL) is a rare form of cytotoxic T-cell lymphoma. It is believed that SPTL in patients without hemophagocytic syndrome (HPS) follows an indolent course; in contrast, SPTL in patients with HPS has been associated with unfavorable survival. To provide more clinical data on SPTL in Asian populations and to identify optimal therapeutic strategies for SPTL, we assessed the clinicopathological features and long-term follow-up data of 10 Taiwanese SPTL patients diagnosed at a single center. Our study demonstrates a group of patients with high incidence of HPS (50%), rather aggressive courses, and early progression. A total of eight patients underwent hematopoietic stem cell transplant (HSCT), including one autologous HSCT and seven allogeneic HSCT. Seven of eight patients receiving HSCT achieved durable remission and maintained in remission for over 30 months (range 30-132 months). There was no difference in 3-year survival of patients with HPS (80%) compared with patients without HPS (80%). Of long-term survivors in the HPS group, three of four received HSCT (autologous HSCT, n = 1; allogeneic HSCT, n = 2). Our study indicated that HSCT is a curative option for eligible SPTL patients with HPS.

Primary Pediatric Cutaneous T-Cell Lymphoproliferative Disorders: 3 New Cases

Primary cutaneous lymphoproliferative disorders are a composite group of diseases with considerable differences in histopathologic, immunophenotypic, and clinical features. They are exceedingly rare in children and in the literature only few cases are reported with extremely different therapeutic approaches. Because of the rarity of cutaneous lymphomas we consider crucial to increase the knowledge of these diseases providing every single case. We present 3 pediatric cases of primary cutaneous T-cell lymphomas occurred to our center with different features and therapeutic approach.

Cutaneous Hematolymphoid and Histiocytic Proliferations in Children

This article focuses on cutaneous hematopoietic neoplasms that are more likely to be encountered in the pediatric age-group and includes both lymphoproliferative and histiocytic disorders. The cutaneous hematologic disorders in children have a different epidemiologic profile to what is seen during adulthood. Although mycosis fungoides is the most frequent form of cutaneous lymphoma in adults, it is very rare in children. Because lymphoblastic leukemias and lymphomas are more frequent in the pediatric setting, cutaneous leukemic infiltrates are relatively common in this age-group. Similarly, histiocytic disorders are more common in children, particularly Langerhans cell histiocytosis and juvenile xanthogranuloma. Notably, the histiocytic disorders have undergone significant modifications on their nomenclature in the basis of the molecular characteristics that are present in them. A summary of the most frequent cutaneous hematopoietic disorders in children will be discussed further in this review.

Biological and clinical significance of tryptophan-catabolizing enzymes in cutaneous T-cell lymphomas

Indoleamine 2,3-deoxygenase 1 (IDO1) induces immune tolerance in the tumor microenvironment (TME) and is recognized as a potential therapeutic target. We studied the expression of both IDO1 and the related tryptophan 2,3-dioxygenase (TDO) in several different subtypes of cutaneous T-cell lymphoma (CTCL), and evaluated the kynurenine (KYN) pathway in the local TME and in patient sera. Specimens from the total of 90 CTCL patients, including mycosis fungoides (MF, n = 37), lymphomatoid papulosis (LyP, n = 36), primary cutaneous anaplastic large cell lymphoma (pcALCL, n = 4), subcutaneous panniculitis-like T-cell lymphoma (SPTCL n = 13), and 10 patients with inflammatory lichen ruber planus (LRP), were analyzed by immunohistochemistry (IHC), immunofluorescence (IF), quantitative PCR, and/or liquid chromatography-tandem mass spectrometry (LC-MS/MS). Three CTCL cell lines also were studied. Expression of both IDO1 and TDO was upregulated in CTCL. In MF specimens and in the MF cell line MyLa2000, IDO1 expression exceeded that of TDO, whereas the opposite was true for LyP, ALCL, and corresponding Mac1/2A cell lines. The spectrum of IDO1-expressing cell types differed among CTCL subtypes and was reflected in the clinical behavior. In MF, SPTCL, and LyP, IDO1 was expressed by malignant cells and by CD33⁺ myeloid-derived suppressor cells, whereas in SPTCL CD163⁺ tumor-associated macrophages also expressed IDO1. Significantly elevated serum KYN/Trp ratios were found in patients with advanced stages of MF. Epacadostat, an IDO1 inhibitor, induced a clear decrease in KYN concentration in cell culture. These results show the importance of IDO1/TDO-induced immunosuppression in CTCL and emphasize its role as a new therapeutic target.

Subcutaneous Panniculitis-Like T-Cell Lymphoma in Children: A Review of the Literature

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a type of skin lymphoma. Pleomorphic T-cells infiltrate the subcutaneous tissue and mimic lobular panniculitis. We report a case occurring in a 12-year-old Chinese boy who presented with multiple indolent erythematous subcutaneous nodules on both extremities without systemic symptoms. He had a protracted course of multiple erythematous subcutaneous nodules for 1 year and underwent biopsy of lesional skin for histology and T-cell receptor (TCR) gene analysis. Histopathology showed infiltration of medium to large atypical pleomorphic cells involving the subcutis with characteristic rimming of fat spaces. TCR gene rearrangement shows monoclonal rearrangements of the TCR β and γ chains. Immunophenotypic studies showed that CD3, CD4, and CD8 were strongly and diffusely positive in lesional cells and that CD56 was focally positive. In contrast, these cells were negative for CD20, CD30, and CD68. The combined morphology, characteristic histologic features, and positive T-CR gene rearrangement supported a diagnosis of SPTCL. He is being treated with combination chemotherapy of cyclophosphamide, doxorubicin, vincristine, and prednisolone.