G59(P) An abscess on the chest wall – don’t forget the great masquerader

Introduction Musculoskeletal tuberculosis (TB) occurs in 1%–3% of patients with the disease. However cold abscess of the chest wall is rare and constitutes 1% to 5% of all cases of musculoskeletal TB. Moreover it is only described in cases of severe or disseminated form of the disease and not as the first presenting feature. Patients are often young and have no comorbidity. Diagnosis is often delayed because of the atypical presentation and lack of awareness. We describe a case of anterior chest wall mass as the first presenting feature of tuberculosis. Case h istory A 15 year old Bangladeshi girl presented to us with a 2 month history of progressively increasing mass on the left anterior chest wall. She had a history of cough and intermittent fever over the preceding 2 weeks. There were no other systemic symptoms. Her immunisations were up-to-date and had received BCG at birth. On examination she had a 6 cm ×4 cm mass overlying the left 8th and 9th ribs, associated with an enlarged left supraclavicular lymph node. A chest x-ray showed the mass eroding into the underlying 8th rib and a left hilar nodal shadow with a small left pleural effusion. The patient underwent a diagnostic biopsy to exclude malignancy. This revealed a fluid filed centre and a significant amount of pus was drained. A post- biopsy chest X-ray showed a markedly enlarged pleural effusion. The patient’s QuantiFERON test was positive (16.05 iu/ml). The fluid was sent for culture and sensitivity and this confirmed drug sensitive Mycobacterium tuberculosis . The patient was treated with standard Anti-Tubercular Therapy and had an uneventful recovery. Conclusion Tuberculosis is a great masquerader and atypical presentations are known to occur. TB should be considered in children presenting with a chest wall mass even if they have been vaccinated with BCG. Other differential diagnoses include benign and malignant tumours. Prompt diagnosis and treatment of chest wall TB results in complete recovery and helps in preventing serious complications.