Disseminated Mycobacterium avium intracellulare complex presenting as abdominal pain

Abstract

A 50-year-old female presented with three months of progresive “sharp and gnawing” epigastric pain, fevers, and night sweats. edical history included systemic lupus erythematosus requiring mmunosuppression with prednisone and mycophenolate. Comuted tomography of the abdomen displayed upper growth of a esenteric lymph node with surrounding stranding (Fig. 1A). Endocopic ultrasound (EUS) revealed a hypoechogenic 2.2 cm lymph ode tangent to the fourth portion of the duodenum (Fig. 1B). US-guided needle aspiration showed inflammatory tissue, which tained positive for acid-fast bacilli (AFB), and culture of biopsy issue confirmed Mycobacterium avium complex (MAC). Multile sputum cultures also demonstrated MAC on Kinyoun stain Fig. 1C), and disseminated MAC was diagnosed. Patient received azithromycin, ethambutol, and rifabutin for one year and symptoms gradually resolved; azithromycin prophylaxis was continued indefinitely to prevent recurrence. MAC is a rare cause of abdominal pain and often difficult to diagnose. MAC, including M. avium and M. intracellulare, are free-living non-tubercular mycobacteria that are ubiquitous in the environment [1]. They usually cause lung disease but can cause disseminated disease in severely immunocompromised patients [1]. Diagnosis is aided by clinical, radiological, microbiological, and pathological findings [1]. Culture requires six weeks of growth before confirmed negative and has to be performed on special media, in addition, AFB staining has low sensitivity and can be falsely negative [1].