Hemophagocytic lymphohistiocytosis as a harbinger of aggressive lymphoma: a case series.

Hemophagocytic lymphohistiocytosis (HLH) is a rare hyperinflammatory syndrome, which can manifest either secondary to a variety of underlying causes, or due to a primary genetic defect. Malignancy is the most common underlying disease in adults with HLH, with lymphomas being the most common malignancy. Lymphoma-associated hemophagocytic syndrome (LAHS) typically follows a rapidly progressive clinical course and is associated with poor prognosis. We herein present four patients with HLH associated with aggressive lymphoma. At initial presentation, the underlying etiology of the HLH was unclear. Two patients were eventually diagnosed with anaplastic large cell lymphoma, while the other two had diffuse large B cell lymphoma. Two of the patients experienced rapid clinical deterioration, one at diagnosis and the other at relapse, and both died prior to diagnosis of lymphoma despite HLH-directed therapy. These cases highlight the need for intensive management in adults with HLH without a clear etiology, especially in cases when lymphoma-associated HLH is suspected. We describe the current pitfalls in diagnosis and treatment of LAHS and discuss possible ways to improve patient management.