The Diagnosis of Pulmonary Tuberculosis in a Patient with AA Amyloidosis of Unknown Etiology

It is of utmost importance to consider tuberculosis as a differential diagnosis while investigating secondary amyloid A (AA) amyloidosis, especially in developing countries. An early diagnosis of tuberculosis as the primary cause of secondary AA amyloidosis is important for precise treatment and recovery of the patient. In this case report, we aimed to increase awareness of tuberculosis as an underlying cause of secondary amyloidosis by discussing the clinical features with a review of the literature. A 74-year-old female patient presented with dyspnea. A detailed clinical and laboratory examination revealed impairment in renal function tests, leukocytosis, anemia, high procalcitonin values, pleurisy and pneumonic infiltration in the left lung. From her history, it was learned that 2 years ago, liver and inguinal lymph node lymph node biopsy was reported as systemic AA amyloidosis. Due to the increased serum creatinine values and a decrease in urine output, the patient underwent hemodialysis for a short period of time, and a decrease in urea and creatinine levels was observed after dialysis and adequate urine output was achieved. Mycobacterium tuberculosis complex was detected in the Bronchoalveolar lavage sample taken during bronchoscopy. Congo red staining of the pathology material was compatible with amyloid in the vessel wall, and immunohistochemical staining was positive for AA. The patient was transferred to the tuberculosis service for anti-tuberculosis treatment. In this case, chronic inflammation due to tuberculosis is thought to be in the etiology of secondary amyloidosis. The authors emphasize that secondary amyloidosis should be among our differential diagnoses in patients with nephrotic syndrome and previous tuberculosis history.