Avascular necrosis of humeral head in an elderly patient with tuberculosis: a case report

INTRODUCTION: Osteonecrosis (avascular necrosis) is known to be caused by high-dose corticosteroid therapy, alcoholism and rarely by infections. However, a tubercular etiology of this condition is very rare. A review of the literature yielded only a few cases of polyarticular tuberculosis with osteonecrosis in immunosuppressed individuals. No case of monoarticular tubercular osteonecrosis diagnosed by aspiration cytology was found. Since tuberculosis is a curable disease, an early and accurate diagnosis is essential. CASE PRESENTATION: A 60-year-old Indian man presented with diffuse swelling and pain in the left shoulder for the previous 6 months. A computed tomography scan of the left shoulder revealed crescentic lucency in the humeral head, suggestive of osteonecrosis. Fine needle aspiration cytology smears from the swelling showed features of an acute suppurative lesion. Stain for acid-fast bacillus was positive and thus, a final clinico-pathological diagnosis of osteonecrosis of humeral head with tubercular etiology was rendered. The patient was initiated on anti-tuberculous therapy with symptomatic improvement in his condition. CONCLUSION: Osteonecrosis, a debilitating disease, may rarely occur due to tuberculosis, especially in endemic areas. Fine needle aspiration cytology is an effective and inexpensive modality for an early diagnosis of the tubercular etiology of osteonecrosis.