title: Xanthogranulomatous pyelonephritis presenting as acute pleuritic chest pain: a case report.
abstract: BACKGROUND
  Xanthogranulomatous pyelonephritis is a rare and serious manifestation of chronic kidney inflammation that can be life-threatening if not recognized and treated appropriately, often with antibiotics and surgery. Affected patients are most commonly females in their fifth or sixth decade of life with a background of obstructive uropathy, nephrolithiasis, or recurrent urinary tract infections who present with vague nonspecific symptoms.
  
  
  METHODS
  A 43-year-old woman of Russian ethnicity with a history of nephrolithiasis presented to our emergency department with new left-sided pleuritic chest pain amid a 6-week history of constitutional symptoms including fevers, night sweats, and 7 kg of weight loss. Workup for acute coronary syndrome and pulmonary embolism in our emergency department was negative. Given that she was clinically unwell, she was admitted to internal medicine to expedite workup for the cause of her symptoms. A broad differential diagnosis for various infectious, inflammatory/autoimmune, and neoplastic processes was considered. Based on classic radiographic and histopathologic findings, she was ultimately diagnosed with xanthogranulomatous pyelonephritis of her left kidney, which was a direct consequence of chronic inflammation. This inflammation exhibited spread to local tissues and across her left hemidiaphragm, resulting in a unilateral pleural effusion which explained her chest discomfort. She was treated with antibiotics administered intravenously and urgent total nephrectomy with a good functional outcome.
  
  
  CONCLUSIONS
  Our case illustrates an uncommon but clinically important do-not-miss diagnosis that underlies a common clinical presentation of pleuritic chest pain. The case underscores the importance of maintaining a broad differential diagnosis and organized approach when treating patients with undifferentiated clinical presentations.
authors.affiliation: Department of Medicine, University of Calgary, Calgary, Alberta, Canada. Justin.Chow@albertahealthservices.ca.
authors.forename: Justin
authors.initials: J
authors.lastname: Chow
authors.affiliation: Department of Medicine, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Rameez
authors.initials: R
authors.lastname: Kabani
authors.affiliation: Department of Medicine, University of Calgary, Calgary, Alberta, Canada.|Department of Medicine, Division of Endocrinology and Metabolism, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Kirstie
authors.initials: K
authors.lastname: Lithgow
authors.affiliation: Department of Medicine, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Magdalena A
authors.initials: MA
authors.lastname: Sarna
mesh_terms: D061605:Administration, Intravenous; D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D002637:Chest Pain / Q000209:etiology*; D005260:Female; D005334:Fever / Q000209:etiology; D006801:Humans; D009392:Nephrectomy; D053040:Nephrolithiasis / Q000150:complications* / Q000382:microbiology / Q000503:physiopathology; D010996:Pleural Effusion / Q000175:diagnosis* / Q000382:microbiology / Q000628:therapy; D011705:Pyelonephritis, Xanthogranulomatous / Q000175:diagnosis* / Q000382:microbiology / Q000628:therapy; D016896:Treatment Outcome; D015431:Weight Loss
chemical_list: D000900:Anti-Bacterial Agents
keywords: Pleural effusion; Pleurisy; Pleuritic chest pain; Pyelonephritis; Xanthogranulomatous pyelonephritis