# Critical Connections: Diagnosis of Epstein-Barr Virus (EBV)-Positive Nasopharyngeal Carcinoma-Associated Hemophagocytic Lymphohistiocytosis

## TL;DR

This paper presents a case of a patient with a history of EBV-related cancer who developed a severe and fatal immune condition called HLH.

## Contribution

The paper emphasizes the importance of diagnosing HLH in patients with a history of EBV-positive nasopharyngeal carcinoma.

## Key findings

- The patient met diagnostic criteria for EBV-associated hemophagocytic lymphohistiocytosis (HLH).
- The patient's condition rapidly deteriorated despite treatment with etoposide and methylprednisolone.
- The case underscores the need to consider HLH in the differential diagnosis of undifferentiated multisystem syndromes in such patients.

## Abstract

Hemophagocytic lymphohistiocytosis (HLH) is a rare and potentially fatal condition associated with Epstein-Barr virus (EBV) in children and adults. We report a case of a 65-year-old male with a history of EBV-positive nasopharyngeal carcinoma in remission presenting with fever, altered mental status, abdominal pain, and generalized weakness. Labs showed pancytopenia, hyponatremia, hypochloremia, acute-on-chronic kidney injury, and hypoalbuminemia. The patient was started on empiric broad-spectrum antimicrobials, intravenous crystalloids, and red blood cell transfusions. HLH was suspected, and laboratory evaluation demonstrated elevated EBV viral load, ferritin, and soluble interleukin-2 receptor levels. He met diagnostic criteria for HLH and was started on etoposide and methylprednisolone. However, due to rapid deterioration, the family requested hospice care, and the patient passed away four days later. This case highlights severe presentations of HLH and the importance of considering HLH in the differential diagnosis of patients with nasopharyngeal carcinoma presenting with undifferentiated multisystem syndromes.