A novel vacuolar myopathy with dilated cardiomyopathy.

UNLABELLED: An 18-year-old previously healthy Filipino male presented with abdominal pain, vomiting, dyspnoea and fever. Initial investigations revealed severe hepatosplenomegaly, pancytopaenia, elevated liver enzymes, coagulopathy and extremely high ferritin levels. Bone marrow biopsy confirmed an abnormal CD8+ T-cell population with haemophagocytosis. Extensive workup was performed, and he was ultimately diagnosed with haemophagocytic lymphohistiocytosis (HLH) secondary to Epstein-Barr virus-positive T-cell lymphoma of childhood (EBV-TCL), a rare and aggressive malignancy. Despite the initiation of modified dexamethasone, methotrexate, ifosfamide, L-asparaginase and etoposide (SMILE) chemotherapy along with high-dose glucocorticoids, the patient did not respond to the treatment and expired. This case underscores the critical importance of early recognition and prompt intervention in EBV-TCL-associated HLH which is a unique condition and a rare entity. The diagnosis of this entity can be particularly challenging, given its rapid progression and high mortality rate. Therefore, timely diagnosis and the initiation of appropriate therapy are essential for improving patient outcomes. General medicine providers play a key role in identifying warning signs to avoid delays in treatment initiation.

LEARNING POINTS: EBV-associated T-cell lymphoma with haemophagocytic lymphohistiocytosis can affect not only children but also adolescents and young adults, highlighting the need for awareness of the high fatality risk.Early recognition of EBV-associated haemophagocytic lymphohistiocytosis (EBV-HLH) is crucial; when a patient presents with fever, pancytopaenia and hepatosplenomegaly.Future prospective studies are warranted to determine the treatment strategy and the optimal patient population that requires early bone marrow transplantation when initial treatment is inadequate.