Unraveling the mystery of fever of unknown origin: a remarkable journey towards the diagnosis of peripheral T-cell lymphoma-T follicular helper type: A rare case report.

INTRODUCTION: Fever of unknown origin (FUO) remains one of the most challenging clinical conditions. It demands an exhaustive diagnostic approach, considering its varied etiologies spanning infectious, autoimmune, inflammatory, and malignant causes. PATIENT CONCERNS: This report shows the journey of diagnosing a 28-year-old male who presented with persistent fever and lower-extremity weakness over 9 months. Despite seeking care at multiple hospitals, a definitive diagnosis remained elusive. DIAGNOSIS: The patient underwent a series of evaluations in various specialties, including gastroenterology, infectious diseases, rheumatology, hematology, and cardiology. Multiple tests and treatments were administered, including antiviral therapy for hepatitis B and antibiotics for suspected infections. INTERVENTIONS: After an initial misdiagnosis and unsuccessful treatments, a positron emission tomography-computed tomography scan and lymph node biopsy ultimately led to the diagnosis of peripheral T-cell lymphoma-T follicular helper type (PTCL-TFH) lymphoma. The patient was referred to the hematology clinic and initiated on CHOEP (cyclophosphamide, vincristine, etoposide, and prednisone) chemotherapy. OUTCOMES: The patient showed a positive response to CHOEP therapy, as indicated by a posttreatment positron emission tomography-computed tomography scan. He reported a significant improvement in his quality of life. Additional rounds of the same regimen were planned to further manage the lymphoma. CONCLUSION: This case emphasizes the importance of a comprehensive and persistent diagnostic approach in managing FUO. Initially, the focus on infectious causes led to extensive treatments, but the disease's progression and complications shifted attention to other specialties. The eventual diagnosis of PTCL-TFH lymphoma highlights the significance of advanced imaging techniques and multidisciplinary collaboration in uncovering elusive diagnoses. Thorough surveillance, timely reassessments, and repeated testing can uncover definitive changes critical for diagnosis. PTCL-TFH lymphoma, although rare, should be considered in the differential diagnosis of FUO, especially when initial evaluations are inconclusive.

Comparative Analysis on Clinical Characteristics Among Patients with Acute Hepatitis A Virus (HAV) and Patients with Acute Hepatitis E Virus (HEV): A Single-Center Retrospective Study from Bulgaria.

Introduction: The acute viral hepatitis was one of the most common conditions in daily clinical practice varying in different parts of the world. The aim of the present study was to perform a comparative analysis on clinical characteristics among patients with acute hepatitis A virus (HAV) infection and patients with acute hepatitis E virus (HEV) infection admitted to the Military Medical Academy (MMA), Sofia, Bulgaria. Methods: A retrospective study was performed at MMA, between 1 January 2016 and 31 December 2021. The etiological diagnosis was confirmed by enzyme-linked immunosorbent assay (ELISA) HAV/HEV IgM serology assays. Results: The current survey included 231 patients with mean age 45.11 ± 16.08 years (95% confidence interval: 43.04-47.19). According to the case definition, inclusion and exclusion criteria, persons were divided into two groups: patients with acute HAV infection (68.4%; 158/231) and patients with acute HEV infection (31.6%; 73/231). Males with HEV had 3.091 times the odds of comorbidity "hypertension" than males with HAV (p = 0.032). There were almost equal odds of increased ALT (odds ratio = 0.999; p = 0.003) in men with HEV and men with HAV. Females with HEV had 5.161 times the odds of comorbidity "hypertension" compared with females with HAV (p = 0.049). We found almost equal odds for elevated ALT in women with HEV and women with HAV (OR = 0.999; p = 0.025). In the non-elderly group (<60-year-old), HEV individuals had 4.544 and 10.560 times the odds of comorbidities "hypertension" and "cardiovascular diseases" compared with HAV patients (p < 0.05). We found almost equal odds for elevated ALT in HEV patients and HAV participants (OR = 0.998; p = 0.002). Conclusion: The results from the current study may support the physicians daily care for patients with acute HAV and acute HEV.

Epidemiological characteristics and clinical manifestations of hepatitis E virus infection in Bulgaria: A report on 20 patients.

INTRODUCTION: Hepatitis E is one of the leading clinical manifestations of acute viral hepatitis in developing countries. In industrialized countries, during the past several years, sporadic "autochthonous" cases of HEV infection have been increased. OBJECTIVE: The aim of this study was to analyze the epidemiological, clinical and laboratory features of HEV infection among patients hospitalized at the Department of Infectious Diseases in Military Medical Academy, Sofia, Bulgaria. METHODS: A retrospective study of 806 cases of acute viral hepatitis was performed at the Department of Infectious Diseases in Military Medical Academy, Sofia, Bulgaria, between December 2004 and September 2012.The etiological diagnosis was established by ELISA. The statistical analysis was performed using Excel 2007 (Microsoft, Redmond, Washington, USA) and SPSS Statistics 19.0 (IBM Corp., Armonk, NewYork, USA). RESULTS: Specific reaction to anti-HEV-IgM and anti-HEV-IgG antibodies were detected in 20 (2.48%) of 806 patients. The most observed clinical presentations were jaundice (85%), fatigue (85%), anorexia (65%), abdominal discomfort (55%) and fever (40%). The mean values of aspartate transaminase and alanine transaminase were 521 IU/l and 881 IU/l, respectively. The cholestasis was slight, marked with mean values of gamma-glutamyl transferase and alkaline phosphatase, respectively 418 IU/I and 486 IU/I. CONCLUSION: We report twenty autochthonous sporadic cases of acute infection with HEV. The zoonotic etiology of the virus as well as the foodborne transmission of the infection is discussed. We found that aging and pre-existing underlying diseases are risk factors for a severe course of the HEV infection.