Comparing axillary and mediastinal lymphadenopathy on CT in children with suspected pulmonary tuberculosis

Radiographic demonstration of mediastinal lymphadenopathy is important for the diagnosis of pulmonary tuberculosis (PTB). Plain radiographs are unreliable for this and CT, which is relatively more expensive and carries a high radiation burden, remains the gold standard. No studies correlating the presence of axillary with mediastinal lymphadenopathy have been reported. Such a correlation would allow for clinical or ultrasound diagnosis of PTB via the axilla.

To correlate the presence of axillary lymphadenopathy with mediastinal lymphadenopathy in children with suspected PTB.

CT scans were performed and reviewed in 100 children (prospectively recruited) with suspected PTB. The axilla and mediastinum were reviewed separately by covering the non-relevant sections on the CT scans prior to reading. Only nodes greater than 1 cm were regarded as pathological.

Mediastinal lymphadenopathy was present in 46% of children; 70% had lymphadenopathy in either axilla. Bilateral axillary lymphadenopathy was identified in 47%. Axillary lymphadenopathy showed a sensitivity of 74% and a specificity of 33% for the presence of mediastinal adenopathy. Bilateral axillary adenopathy had a sensitivity of 50% and a specificity of 56%.

Axillary lymphadenopathy has a moderate sensitivity and low specificity for the presence of mediastinal and hilar lymphadenopathy in children with suspected PTB. Further research should be aimed at correlating ultrasound-detected axillary lymphadenopathy with FNA results in children.