Pulmonary and Urologic Sarcoidosis as a Cause of Intermittent Fever of Unknown Origin.

Diagnosing fever of unknown origin (FUO) presents a substantial challenge due to its potential association with various diseases affecting different organs. In 1961, Petersdorf and Beeson initially defined FUO as a condition characterized by a temperature exceeding 38.3 °C on at least three occasions over a minimum three-week period. Despite a week of inpatient investigation, a definitive diagnosis remains unclear.  Sarcoidosis, a granulomatous disease impacting multiple systems, is among the causes of FUO. While the lungs are commonly affected, any organ can be involved, leading to diverse manifestations and clinical courses. Diagnosis relies on clinicopathologic findings and the exclusion of alternative causes of granulomatous disease. The hallmark of sarcoidosis is the development of granulomas in affected organs. Here, we present the case of a 61-year-old man with a history of recurrent spontaneous periurethral abscesses who underwent multiple urological interventions. He developed FUO during hospitalization following treatment for the infectious condition.

Tropical Sprue: A Rare Cause of Malabsorption Syndrome.

Chronic diarrhea is a common disorder in tropical regions, affecting residents, visitors, and even expatriates. It may stem from a myriad of infectious, inflammatory, and even malignant causes. In patients in whom no etiology has been found, tropical sprue (TS) is an important diagnosis to consider. We report the case of a 60-year-old man originally from Guatemala, presenting with chronic diarrhea and megaloblastic anemia due to severe vitamin B12 deficiency. Biopsies of the small bowel revealed partial villous atrophy and inflammatory infiltrate with the participation of eosinophils. The diagnosis of TS was established after exclusion of other causes of malabsorption syndrome. This is a disease of unknown etiology with complex and multifactorial pathophysiology, with an important component of intestinal dysbiosis. Antibiotics and vitamin supplementation are the pillars of therapy. Awareness of this disorder is essential in preventing delayed diagnosis and subsequent morbidity.

A Rare Cause of Abdominal Pain: IgG4-Related Sclerosing Mesenteritis.

A 67-year-old man with previous cardiovascular disease was referred to our consultation due to a 5-month history of recurrent epigastric pain. Esophagogastroduodenoscopy and full blood workup presented no alterations. CT scan showed an irregularly shaped mass at the root of the mesentery, measuring 40x25x47mm, with spiculated contours and retractile behaviour (a). Simultaneous densification of the adjacent fat and infracentimetric ganglionic formations scattered throughout the mesentery were shown. Surgical biopsy revealed extensive storiform fibrosclerosis, with the presence of interstitial lymphoplasmocytic infiltrate and obliterative phlebitis (b); the plasma cells had mostly IgG expression, with IgG4:IgG ratio >40% (c), accounting for more than 30- 40 IgG4 plasma cells per field. The serum IgG4 level was 137mg/dL. A diagnosis of IgG4-related sclerosing mesenteritis was made, without other organ involvement. Prednisolone (0.6mg/kg/d) improved partially the abdominal pain, so steroid sparing strategy with off-label rituximab was associated. Due to its low prevalence, the understanding of this entity is scarce, and its diagnosis is challenging. Unlike other manifestations of IgG4-related disease, the intra-abdominal disease is identified in later stages, due to unspecific symptoms. This case aims to raise awareness about this condition as a differential diagnosis of abdominal pain.