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.

Lower vitamin D levels are associated with the pathogenesis of inflammatory bowel diseases.

Vitamin D plays a role in regulating immune homeostasis, inflammation and has an impact on the pathogenesis of inflammatory bowel diseases (IBD). IBD has a multifactorial pathogenesis primarily associated with immune dysregulation, dysbiosis, structurally altered intestinal mucosa, and genetic factors. The immunomodulatory function of this vitamin is linked to its control over innate and adaptive immunity, facilitated through its nuclear vitamin D receptor, leading to the inhibition of nuclear factor kappa-B.

Renal cell carcinoma presented with a rare case of icteric Stauffer syndrome: A case report.

Background: Paraneoplastic syndromes remain poorly understood and manifest as multifaceted clinical symptoms, making their diagnosis difficult. Cholestasis can be observed in various malignancies. In rare cases, it can be a paraneoplastic manifestation, most often associated with renal cell carcinoma and other urogenital tumors, as well as with bronchial carcinoma.