Unilateral absence of right pulmonary trunk: A rare case presentation in a 40-year-old male with respiratory symptoms

We present a unique case of a 40-year-old male presenting with chief complaints of breathlessness and intermittent chronic cough. High-resolution computed tomography (HRCT) revealed architectural distortion of the right lung, characterized by irregular reticulations and smooth inter and intra-lobular septal thickening with mild microcytic honeycombing, exhibiting an apicobasal gradient along the sub-pleural border. Additionally, ipsilateral mild pleural thickening was observed. Bilateral lung fields showed multiple fibrotic bands and streaks with tractional bronchiectasis, leading to volume loss manifested by ipsilateral mediastinal shift and contralateral lung hyperinflation. Subcentimetric lymph nodes were noted in the bilateral lower para tracheal and pre-vascular regions. Despite a normal heart size, HRCT revealed isolated unilateral right-sided absence of the pulmonary artery, accompanied by hypervascular ipsilateral collateral vasculature. Atherosclerotic changes and calcified plaque were evident in the aorta, with significant thickening. This case underscores the importance of thorough investigation in patients presenting with respiratory symptoms, as rare anatomical anomalies such as unilateral absence of the pulmonary trunk may have significant clinical implications and require tailored management strategies.