Clinical features of infantile subcutaneous panniculitis‐like T‐cell lymphoma

Abstract

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a T-cell lymphoma that develops from subcutaneous fat tissue. Pediatric SPTCL is rare, with extremely few infantile cases reported. The patient was a three-month-old boy who visited the hospital with a primary complaint of a subcutaneous mass. He had an enlargement of the cervical lymph nodes, no hepatosplenomegaly. A large subcutaneous mass measuring 10 mm in its greatest dimension was found at the right flank, but the color of the skin was normal and no other subcutaneous masses were seen. A blood examination detected marked elevation of serum soluble IL-2 receptor (1,215 U/mL), but other laboratory data were within normal ranges. Bone marrow and cerebrospinal fluid examinations showed not only metastasis of lymphoma cells but also lymphohistiocytosis. Fluorodeoxyglucose-positron emission tomography (FDG-PET)-CT showed an abnormal accumulation in the right cervical and axillary lymph nodes, and in the right flank, right buttocks, and left femur subcutaneous lesions. Pathological findings of right abdominal subcutaneous lesion showed rimming formation by atypical lymphocytes in subcutaneous tissue; these cells were positive for CD3, CD8, and bF-1 and negative for CD4 and CD56 on immunostaining. A T-cell receptor gene rearrangement analysis by polymerase chain reaction revealed a monoclonal pattern for the TCR-b gene and a polyclonal pattern for the TCR-c gene. These findings supported the diagnosis of SPTCL; pathological diagnosis was confirmed by diagnosis system of Japan children’s cancer group. Japanese Pediatric Leukemia/Lymphoma Study Group Classification of newly diagnosed Hematological Malignancy 2014 were approved by Oita University Ethic Committee (No. 505). We received informed consent form signed by the patient’s parent. Based on previous reports and the Japanese Skin Cancer Society guideline, we selected administration of intrathecal methotrexate (MTX; 1 mg) once, and systemic prednisolone (PSL; 1 mg/kg/day, oral) for 3 months, and completed without any severe complications. The patient has been in complete remission for a year. We searched for articles describing SPTCL patients under 15 years of age reported from 2000 to 2018 using the research database PubMed and ultimately identified 27 cases, including four infants. The clinical characteristics of four infantile cases and the present patient are summarized in Table 1. Moreover, the clinical presentations and courses of 27 total cases including the present case were assessed (Table S1). Regarding the clinical characteristics, two of the five infantile cases (40%) had systemic symptoms; fever, sweating, and weight loss. Systemic symptoms were noted in 20 of the total 22 cases (90.9 %) (Table S1). These data suggest that infantile SPTCL is accompanied by systemic symptoms less frequently than that in other age. Furthermore, only 1 of 5 infantile patients had HLH (20%), whereas 10 of other 22 patients (45.5 %) had HLH, which is one of the poor prognosis factors. The HLH complication rate in cases of infantile SPTCL is lower than that in other age, although sample size was relatively small. The treatment strategy for pediatric SPTCL has not yet been described in any guideline. Relatively few case reports have been published. In our review, intensive therapy, such as CHOP regimens, were selected for 14 of the 27 cases, while non-treatment observation was selected in four cases and intensity-reduced therapy, such as oral PSL, with or without other immunosuppressive agents were selected in seven cases. In these seven cases, three cases were treated by both PSL and cyclosporine. Overall survival was ultimately obtained in 22 cases, excluding three patients who died. These dead patients had been treated with intensive chemotherapy as the initial therapy. All three patients died due to treatment complications. Therefore, for pediatric SPTCL, especially those without HLH, we suggest that intensityreduced therapy be considered as the first treatment strategy in order to avoid treatment deaths. PSL, cyclosporine, or combination with these agents as intensity-reduced therapy may be effective for pediatric SPTCL. In addition, in infantile case, severe adverse reactions, including infections or developmental problems, may be induced by intensive therapy. In the present patient, Correspondence: Hironori Goto, MD, Department of Pediatrics, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita, 879-5503, Japan. Email: [email protected] Received 30 May 2019; revised 5 August 2019; accepted 1 October 2019. doi: 10.1111/ped.14017