Tsutsugamushi lymphadenitis with multiple viral infections:report of a case

LU Yun-long; FU Cai-bo; XUE Feng-gui; NIU Hai-yan

doi:10.3969/j.issn.1007-8096.2025.03.027

Abstract：Objective To explore the clinical pathological features and prognosis of a case of scrub typhus (TD)-induced lymphadenitis with multiple viral infections and TCR gamma clonal rearrangement. Methods A case of scrub typhus infection was collected from the First Affiliated Hospital of Hainan Medical University in 2021. Clinical imaging and gross characteristics, histological morphology, immunohistochemical expression, and prognosis were observed, and a literature review was conducted. Results The patient was a middle-aged male with right cervical lymph node enlargement for 5 days, with a maximum temperature of 39.5°C, accompanied by chills, night sweats, sore throat, and occasional cough. Laboratory tests: high-throughput pathogen detection showed positive for Orientia tsutsugamushi. EBV virus (EBV DNA) quantification: 8.87×10^3 (positive). IgM antibodies for herpes simplex virus type I and rubella virus were positive. Microscopically, the lymph node structure was largely destroyed, replaced by proliferating small lymphocytes and sinus histiocytes. Immunohistochemistry suggested that the proliferating small lymphocytes were mainly T lymphocytes with positive expression of cytotoxic markers. EBER in situ hybridization was diffusely positive, and Ki-67 was positive (40%). Molecular pathology results: TCR gamma rearrangement test was positive. The patient was treated with doxycycline-like drugs, and the clinical symptoms improved. After surgery, the patient was followed up for 3 years and remained healthy. Conclusion Scrub typhus infection can coexist with multiple viral infections and is associated with positive TCR gamma clonal rearrangement, which may lead to missed or misdiagnosis. During diagnosis, it is important to fully understand the medical history, pay attention to clinical laboratory testing, and closely follow up on the patient's recovery.