Background: Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is an uncommon subtype of peripheral T-cell lymphoma and its standard treatment remains ongoing study. Cases refractory to chemotherapy are suggested to benefit from autologous hematopoietic stem cell transplantation (auto-HSCT). Nevertheless, post auto-HSCT recurrence seems to be irreversible. Very few cases of allogeneic-HSCT (allo-HSCT) in SPTCL have been reported so far.
Case Report: A 27-year-old female presented to our hospital with refractory SPTCL for receiving auto-HSCT. Cutaneous biopsy had confirmed diagnosis of SPTCL at a local hospital, where 5 lines and 10 cycles of intensive chemotherapy had been prescribed. All these treatment provided marginal control of disease progression. After her enrollment at our institute, she relapsed again after the collection of peripheral hematopoietic stem cells. Then, we performed an allo-HSCT to her from a 10/10 matched unrelated donor. Neutrophil and platelet engraftment occurred at day +11 and +13, respectively. At day +15, lymphoma, however, came back, resulting in the withdrawal of cyclosporine from day +35 to day +75, when acute graft versus host disease (aGvHD) emerged. Lymphoma cells were observed in a subcutaneous biopsy from her leg. Eventually, skin manifestation of extensive chronic GvHD developed. By present, the patient has sustained complete remission for 18 months.
Conclusions: Allo-HSCT is rational for patients with refractory SPTCL. To our knowledge, this is the first case, with regained remission after post allo-HSCT relapse through cyclosporine withdrawal, showing the existence of graft versus lymphoma (GvL) effect in SPTCL.

Keywords: graft versus lymphoma effect, subcutaneous panniculitis-like T-cell lymphoma, allogeneic hematopoietic stem cell transplantation