Hemophagocytic Lymphohistiocytosis (HLH) in an Elderly Male With Epstein-Barr Virus (EBV) Viremia.

This is a case of a 75-year-old male with a complicated past medical history who presented initially with weakness, fevers, exertional dyspnea, cough, and confusion. His initial workup revealed elevated aspartate transaminase (AST), alanine transaminase (ALT), bilirubin, and D-dimer. Right upper quadrant (RUQ) ultrasound revealed a partially contracted gallbladder with gallstones, so he underwent laparoscopic cholecystectomy. Due to worsening hyperbilirubinemia and anemia, he later underwent a liver biopsy which showed Epstein-Barr virus (EBV)-positive lymphoid infiltration. He developed anemia, thrombocytopenia, and low fibrinogen. He met the criteria for hemophagocytic lymphohistiocytosis (HLH) with 6/8 HLH-2004 criteria and an H score of 230 with a 96-98% probability of HLH. The patient was promptly treated with steroids, rituximab, and etoposide; however, the patient's health continued to deteriorate, and he expired. This case highlights the challenges of early diagnosis of HLH in the elderly patient population due to large differentials, confounding comorbidities, and the rarity of the diagnosis in this age range.