Abstract
Persistent pure ground-glass opacities (GGOs) are often associated with indolent lung adenocarcinoma, yet their natural history beginning in adolescence has rarely been documented. We report an exceptionally rare case of adenocarcinoma in situ (AIS) diagnosed after 12 years of radiological follow-up of a pure GGO initially detected at 14 years of age. A 26-year-old never-smoker was referred to our department because of gradual enlargement of a pure GGO in the right upper lobe. The lesion had been incidentally detected during preoperative evaluation for dermatofibrosarcoma protuberans of the left upper arm at 14 years of age. Serial chest CT demonstrated slow enlargement from 5.4 to 12 × 9 mm over 12 years without development of a solid component. Because primary lung adenocarcinoma was strongly suspected, the patient underwent video-assisted thoracoscopic extended right posterior segmentectomy (S2). Histopathological examination demonstrated lepidic proliferation of atypical pneumocytes without stromal invasion, confirming AIS (pTisN0M0, Stage 0). The postoperative course was uneventful, and the patient remains recurrence-free 2 years after surgery. This case provides a rare opportunity to observe the natural history of an AIS-associated pure GGO from adolescence to adulthood. Persistent enlargement of a pure GGO, even without development of a solid component, may warrant consideration of surgical resection in appropriately selected young patients.