Unusual presentation of anaplastic large cell lymphoma with clinical course mimicking fever of unknown origin and sepsis: autopsy study of five cases.

AIM To describe a subset of cases with the unusual clinical and histomorphological presentation of anaplastic large cell lymphoma (ALCL) mimicking fever of unknown origin (FUO) and sepsis. METHODS A pathology database was searched using full term Systematized Nomenclature of Medicine codes for ALCL to identify 23ALCL cases from the period 1999-2006. Of those, five cases that did not have a correct premortem diagnosis were further analyzed to elucidate the reasons for delayed and incorrect pre-mortem diagnosis. The analyzed data included clinical presentation, duration of symptoms, duration of hospital stay, premortem presumed cause of death, white blood cell count, platelet count, anion gap and blood pH, liver enzymes (alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, alkaline phosphatase), lactate, coagulation tests (prothrombin time, partial thromboplastin time, fibrinogen, D-dimers), microbiology cultures, and radiology and surgical pathology reports. Autopsy reports were reviewed for description of major gross findings, initial clinical diagnosis, and cause of death. RESULTS Five fatal and pre-mortem unrecognized ALCL cases were characterized by rapid decline, with histologic findings showing predominantly extranodal involvement, intravascular lymphomatosis, and hemophagocytosis. The cases were also characterized by unusual clinical manifestations including a FUO, sepsis, and disseminated intravascular coagulation-like picture, lactic acidosis, hepatosplenomegaly, and absence of significant peripheral adenopathy. CONCLUSIONS There is a distinct group of ALCLs with unique and specific clinical, gross autopsy, and histopathologic findings. Recognition of this clinical variant may facilitate early detection and potentially timely diagnosis and therapy.