A case report: Infection-related glomerulonephritis and mantle cell lymphoma due to mycobacterium avium complex infection.

RATIONALE: Mycobacterium avium complex (MAC) infection is common in lung, liver and skin. However, MAC presenting with peritonitis is uncommon and is particularly rare in immunocompetent patients. We report a case of infection-associated glomerulonephritis and mantle cell lymphoma caused by peritonitis due to MAC.

PATIENT CONCERNS: We report a case of a 73-year-old elderly man with fever and abdominal pain for 2 days and gradually developed anuria, ascites, and abdominal lymphadenopathy.

DIAGNOSES: The initial diagnosis was peritonitis and acute renal failure. There was no significant relief of symptoms after empirical anti-infective therapy and hemodialysis. infection-associated glomerulonephritis, mantle cell lymphoma, and peritonitis due to MAC were diagnosed by renal biopsy, abdominal lymph node biopsy, and metagenomics next-generation sequencing.

INTERVENTIONS: The patient received empirical antibiotic therapy, hemodialysis, and anti-MAC therapy.

OUTCOMES: Unfortunately, the patient eventually died of septic shock after the 21st day of admissiom.

LESSONS: Early diagnosis of MAC infection is essential. When the cause of fever is unknown, metagenomics next-generation sequencing can be considered.