Type of publication:
*Muthusami R.; *Makan A.; *Ahmad N.; *Srinivasan K.S.; *Moudgil H.
American Journal of Respiratory and Critical Care Medicine; May 2018; vol. 197
RATIONALE Although initially describing Endobronchial Tuberculosis, the Tree-in-Bud (TIB) pattern is increasingly recognised in a wider number of conditions. Objective here was to establish how frequently this was reported and the spectrum of subsequent diagnosis. METHODS Reports relating to all Chest CT scans undertaken at our District General Hospital during 2015 were identified and those with reference to TIB further explored from electronic medical records. RESULTS 27 patients had the TIB (2.7% of total CTs) pattern reported. Average age was 72 years with 59% female. The right lung was affected (78%) more than the left (52%) along with one of the lower lobes (55%). The most common lobe affected was the RLL (41%) followed by the RML (37%) and then RUL & LLL (both 33%). 21 (78%) were seen by a Respiratory Physician. For the group as a whole, two had died from advanced cancer (1 lung cancer) and one with advanced dementia. An Infectious Aetiology was proposed in 16 (59%) with half confirmed with a positive microbiological result. 2 patients had Non-Tuberculous Mycobacteria, alongside Chronic Cavitatory Pulmonary Aspergillosis (1), ABPA (Allergic BronchoPulmonary Aspergillosis) in 3 (11%), Emphysema (3), Asbestos Disease (2) and one each had Pulmonary Sarcoid and BOOP (Bronchiolitis Obliterans Organizing Pneumonia). CONCLUSION The Tree-in-Bud pattern occurs as a result of a number of processes, although often they co-exist in the same condition and though we identified some mycobacterial disease, cases identified had a wider spectrum including other infectious, allergic, and vasculitic pathways alongside malignancy. The radiological distribution of disease within the lungs further proposes a role for silent aspiration into the airways. (Figure Presented) .