Bronchopneumonia is usually seen in children and is caused by several microorganisms including bacteria, fungi and viruses and some migrating larvae of some worms. However, adults are not immune to it. It is not commonly seen in adults. Primary complex is caused by Mycobacterium tuberculosis. It is the primary infection seen in children in India. 70% of us had this infection during our childhood. Most of us recovered without any clinical symptoms. It is also called Ghon's complex (which is a pathological diagnosis). In some children, primary tuberculosis infection may start as bronchopneumonia. Primary complex is too small to be seen through x-ray. It may be visualised through MRI.