Case Presentation: 69-year-old male with past medical history of sarcoidosis was found to have a positive quantiferon gold on outside labs and thus presented to the hospital for TB rule-out. On presentation, patient reported generalized fatigue, weakness and mild shortness of breath for the past year and denied fevers, chills, night sweats, or weight loss. Patient was diagnosed with sarcoidosis in 2022 from PET scan showing hypermetabolic lymph nodes and innumerable enhancing foci throughout the skeleton, with subsequent axillary lymph node biopsy demonstrating non-necrotizing granulomatous lymphadenitis. Patient has a brother with leukemia and had lived in the U.S. all his life. Patient denied tobacco use. On vitals, patient was afebrile, with normal heart rate and blood pressure, saturating well on room air. Exam was notable for palpable purpura and ecchymoses on his extremities. Labs on admission were notable for hemoglobin 10.2, platelets 73, triglycerides 251, and fibrinogen < 60. Ferritin on admission was 19,827 and steadily increased to over 40,000 within two weeks. Further work-up revealed IL2 receptor (CD 25) soluble level of 152,641. CT chest non-contrast showed prominent lymph nodes without active TB changes. PET obtained during hospitalization showed hypermetabolic activity of the skeleton, lymph nodes, and spleen, liver, and pancreas.Repeat right axillary lymph node core biopsy obtained during hospitalization showed large B-cell lymphoma with T-cell-rich background, confirmed by bone marrow biopsy. Molecular testing showed CIITA::BCL6. Patient met criteria for HLH secondary to underlying large B-cell lymphoma. Upon diagnosis, patient was initiated on R EPOCH. After 3 months of treatment, repeat PET showed significant decrease in hypermetabolic activity of all previously affected areas. The secondary HLH improved with treatment, and hematology has continued to monitor for continued therapy with rituximab after R EPOCH. Latent TB was treated under guidance of infectious disease with INH + B6 for 6 months.
Discussion: Since the patient was clinically well-appearing, HLH was not suspected until later in the hospital course until the ferritin level rose to >40,000. As the patient was never clinically unstable, HLH-94 based induction therapy was not initiated by hematology.This case is pertinent to the practice of hospitalist medicine because it illustrates the dangers of anchoring bias, diagnostic momentum, and premature closure that can affect patient management in an inpatient medicine ward. Despite inconsistencies in the patient’s presentation (assumption that granulomatous lymphadenitis on initial axillary biopsy equated likely sarcoidosis despite age of presentation in late 60s and diffuse osseous involvement on initial PET atypical for sarcoidosis), the patient continued to be treated for sarcoidosis for over a year prior to admission, delaying the diagnosis of lymphoma.
Conclusions: Inconsistent data or atypical presentations should prompt reassessment of the differential to ensure timely and accurate treatment of the patient. Diffuse osseous involvement on the initial PET should have alerted clinicians to another possible diagnosis. In patients who appear clinically stable, HLH should still be considered especially with significantly elevated ferritin levels, and once suspected, should prompt a search for the underlying cause of the HLH.