Outcomes in Subcutaneous Panniculitis-Like T-Cell Lymphoma (STCL)

Subcutanous panniculitis–like T cell lymphoma (STCL) is a rare clinical entity which simulates panniculitis and can present with an aggressive clinical course. STCL is divided two major subgroups (αβ-STCL and γδ-STCL), according the T cell receptor expression on the malignant T cells. γδ-STCL is often associated with a more aggressive course and poor prognosis with an 11% 5-yr survival in a retrospective study of 20 cases, only 6 of which were confirmed by TCRδ -1 staining.¹ We report our results from 10 patients with STCL, 2 BetaF1+ (αβ-STCL), 8 γδ-STCL. The median age at presentation was 43 (25–63); 7 of 10 were female. Immunohistochemical studies and TCR gene rearrangements (TCRR) were performed on all patients. Cytotoxic T-cell markers were expressed in all pts (TIA-1 in 8 of 10 and Granzyme B in 5). Six were CD8+ and 3 were CD3+CD4−CD8−. CD56 expression was detected in 3. All demonstrated clonal TCRR. All pts presented with skin nodules or ulcerations, and 3 had visceral involvement (blood/bone marrow in 2, liver in 1). Three patients (2αβ-STCL and γδ-STCL) were treated initially with denileukin diftitox; one each with αβ- and γδ- disease had PR on therapy and have been maintained without PD. Seven patients were treated with cytotoxic chemotherapy regimens. Four of 7 achieved a remission after EPOCH (2), denileukin diftitox-CHOP (1) or pentostatin/cyclophosphamide followed by alemtuzumab (1). Four pts (1 with refractory ab-STCL, 2 with refractory gd-STCL, and 1 with γδ-STCL in first CR after denileukin diftitox-CHOP) underwent allogeneic hematopoietic stem cell (HSCT) from matched-related donors. Two patients are alive 6 and 13 months after HSCT with no evidence of disease; 1 patient died in CR from infectious complications of HSCT, and 1 relapsed 6 mo after HSCT and died from PD. At a median follow up of 3 yrs from diagnosis, 8 pts (80%) are alive, including the 2 pts with αβ-STCL and 6 of 8 pts with γδ-STCL. In summary, while γδ-STCL is reported in retrospective studies to have a poor prognosis, we demonstrate that aggressive therapies along with the incorporation of novel T-cell directed agents such as denileukin diftitox and alemtuzumab into treatment regimens and the use of allogeneic HSCT as a potentially curative therapy are promising approaches for these patients.