Background: An association between hemophagocytic lymphohistiocytosis (HLH) and severe transient left ventricular (LV) hypertrophy has not been described to date. Possible explanations, including etoposide toxicity, are discussed.
Observation: A 2-month-old male infant with HLH was treated according to the HLH-2004 protocol. Initial cardiac evaluation was within normal limits. During the second month of therapy, a heart murmur was discovered; electrocardiogram demonstrated signs of LV hypertrophy, and echocardiogram confirmed the presence of thickness of LV walls. This complication was transient: clinical findings, echocardiogram, and electrocardiogram recorded 6 months afterward were all within normal limits.
Conclusions: The case suggests the need for close echocardiographic monitoring during HLH treatment.