Mycobacterium kansasii chronic olecranon bursitis: A rare case report and literature review

Non-tuberculous mycobacteria are a rare cause of olecranon bursitis. We present a case of a 65-year-old man with history of chronic olecranon bursitis status post bursectomy two years prior, presented with two weeks of right elbow swelling but no pain or redness. On exam, bursa was enlarged with mild warmth present but no concern for elbow joint involvement. The bursa was aspirated, fluid analysis revealed leukocytosis with monosodium urate crystals consistent with gout. Ten days later, the mycobacterial cultures grew <i>Mycobacterium kansasii</i>. Two weeks later, on repeat aspiration of right elbow bursa, fluid cultures grew <i>M. kansasii</i>. He was treated with rifampin, ethambutol and azithromycin. After two months on triple therapy his symptoms resolved. For source control he underwent bursectomy. Histopathology revealed necrotizing granulomas and bursa culture grew <i>M. kansasii</i>. After six months on triple therapy, patient developed ethambutol induced optic neuropathy, thus ethambutol was stopped. Rifampin and azithromycin were continued for total duration of eight months of antibiotic therapy post bursectomy. At six months follow up, patient had no symptoms but vision deficits had not improved from cessation of ethambutol. We did a literature review and compiled the previously three reported cases of <i>M. kansasii</i> olecranon bursitis.