Unilateral Hilar Prominence: A Diagnostic Dilemma!

The radiographic density of the hilum is mainly contributed by the pulmonary arteries and veins, major bronchi, and lymph nodes. Superior pulmonary veins make a small contribution. Though both hila should be indistinguishable in size and density, we do not get equal hila in all the chest X-rays. Rotational malpositioning must be kept in mind, while interpreting chest radiographs of unequal hilum. There are numerous causes of hilar enlargement. It is the clinical presentation which will help in reaching the differential diagnosis. Asymmetric hilum is a challenging subject for clinicians. Interpretation of unequal hilum depends on findings of detail history, meticulous clinical examination, and appropriate investigation.