Different variation of right upper lung apex subsegment.

A 35-year-old female patient presented with a mixed ground-glass nodule located in the right upper lobe of the lung, which led to a suggestion for follow-up in the clinic. After one month, it was noted that the nodule had marginally increased in size, along with an uptick in solid components, which heightened the concern for lung cancer. A three-dimensional reconstruction of the bronchial and vascular structures derived from enhanced CT scans of the chest indicated notable anatomical variations in the upper right segment. The anterior bronchus of the right upper lobe arose from the main bronchus of the right lung, while branches A2a and A2b emerged from the posterior ascending branch of A2, with a lack of any reverse branch from A2. Furthermore, A3 was observed to originate from the right inferior pulmonary trunk, and V3 was noted to be absent.