Hemophagocytic Lymphohistiocytosis in Cutaneous T-Cell Lymphoma.

Importance: Hemophagocytic lymphohistiocytosis (HLH) has been reported as a serious complication of cutaneous T-cell lymphoma (CTCL). Despite available diagnostic guidelines, it remains a diagnostic and therapeutic challenge in this patient population. Objectives: To examine the characteristics of CTCL associated with HLH and analyze the presenting signs and symptoms, therapeutic options, and outcome. Design, Setting, and Participants: In this case series, patients diagnosed with CTCL and HLH who were treated at a single institution from January 1, 2014, through December 31, 2017, were studied. Exposures: The HLH-2004 trial criteria, HScore, and various clinical and histopathologic variables were applied to and analyzed in the cohort. Main Outcomes and Measures: Subtype of CTCL, treatment administered for HLH, and patient outcome were assessed. Results: Seven patients (4 men and 3 women; median age, 50 years; range, 34-77 years) were identified from the database and included in the study. Cytotoxic subtypes of CTCL that involve the deep dermis and subcutaneous tissue were most commonly associated with HLH. Four patients met 5 or more HLH-2004 trial criteria, and 5 had an HScore probability greater than 85% at presentation. Common presenting HLH symptoms were fever and malaise. Cyclosporine, polychemotherapy, and systemic corticosteroids were the most common treatments. Patients receiving allogeneic stem cell transplants had the best outcomes, with all 3 of these patients alive and in complete remission. Conclusions and Relevance: Hemophagocytic lymphohistiocytosis is a life-threatening complication of CTCL associated with rare cytotoxic CTCL subtypes that primarily involve the subcutaneous tissue. Because these cases may resemble a granulomatous or infectious condition, the diagnosis and appropriate management are often delayed. The results of this study demonstrate the need for high awareness of HLH in patients with panniculitic lymphomas and indicate that allogeneic stem cell transplantation may be the best option for a sustained remission.