Subcutaneous panniculitis-like T-cell lymphoma associated with hemophagocytic lymphohistiocytosis: a systematic review of 63 patients reported in the literature

To review and summarize the clinical features, treatment strategies, and prognosis of subcutaneous panniculitis-like T-cell lymphoma complicated with hemophagocytic lymphohistiocytosis (SPTCL-HLH). We searched the Web of Science, Embase, Cochrane Library, and PubMed databases. The keywords were subcutaneous panniculitis-like T-cell lymphoma and hemophagocytic lymphohistiocytosis or hemophagocytic syndrome. The patients were divided into a mutated group and a wild-type group based on the existence of HAVCR2 gene mutation. A total of 45 reports, including 63 patients with SPTCL-HLH, were included in the systematic review. Twelve patients detected gene mutations, including 11 with the HAVCR2 gene mutation and 1 with the STXBP2 gene mutation. Thirty-one patients were tested for autoantibodies. Compared with the wild-type group, patients in the mutated group were younger (p = 0.017), and the autoantibody-positive rate was higher (p = 0.006). The main treatment target of 17 patients was to control HLH, yielding an ORR of 88.2%. Two cases relapsed, and both were treated with corticosteroid monotherapy. The corticosteroid monotherapy experienced a higher recurrence rate than the corticosteroids plus other immunoregulatory agents therapy (66.7 vs. 0.0%, p = 0.029). Eighteen patients received initial anthracycline-based chemotherapy, and 50.0% reached remission. The ORR of initial chemotherapy aiming at controlling HLH was higher than those of anthracycline-based chemotherapy (p = 0.015). The ORR was higher in patients initially controlled for HLH versus chemotherapy without HLH control first (90.5 vs. 61.5%, p = 0.024). Interestingly, one patient with juvenile idiopathic arthritis developed SPTCL-HLH during tocilizumab therapy, discontinuing tocilizumab led to a remission of the disease spontaneously. Sixteen patients received stem cell transplantation (SCT). Fifteen patients, including 5 with relapsed/refractory SPTCL-HLH, responded well and survived after receiving SCT. One case who received a sibling-identical SCT relapsed. Further analysis revealed a homozygous HAVCR2 mutation with the donor. The 2-year overall survival (OS) was 91.0% ± 4.4%. There was a significant difference in the OS among patients of different age groups, and patients aged 40-60 had the lowest 2-year OS (66.7% ± 19.2%). Patients with HAVCR2 gene mutations are younger and more likely to be misdiagnosed with autoimmune diseases. Initial treatment of corticosteroids plus immunoregulatory agents attaches great significance to avoiding too aggressive therapies. Intensive anthracycline-based chemotherapy such as CHOP or CHOP-like regimens can also induce long-term remission for aggressive disease. SCT is still a reliable strategy currently. In addition, a watch and wait approach is recommended in patients with mild SPTCL-HLH caused by drugs. The occurrence of HLH does not necessarily mean a more rapidly progressive disease and worse prognosis in patients with SPTCL, but older patients with SPTCL-HLH may be associated with a lower survival rate.