Abstract Introduction Subsolid pulmonary nodules (SSNs) often represent early lung adenocarcinoma, with invasive risk linked to the growth of a measurable solid component. In patients with prior extrathoracic malignancy, distinguishing a new primary from metastasis can be challenging. We report an eight-year evolution of a left upper lobe (LUL) SSN, re-evaluated after an emergency department (ED) visit, culminating in a diagnosis of well-differentiated nonmucinous adenocarcinoma with lepidic growth. Case Report A 76-year-old woman, a former smoker (7.5 pack-years, quit in 1989), underwent radical cystectomy with Studer neobladder for pT4aN0 urothelial carcinoma (2017). That year, surveillance CT identified a 7-mm pure ground-glass LUL nodule. In December 2022, CT revealed a 12 × 9 mm part-solid nodule with a solid core ∼7 mm in diameter. By August 2023, it had measured 14 × 12 mm with a 7-8 mm solid component and no thoracic adenopathy. A thoracic surgery consultation was conducted to discuss VATS wedge resection versus continued surveillance; the patient opted for surveillance with interval imaging. In 07/2025, she presented to the ED with intermittent left-sided chest discomfort. Chest radiograph revealed a ∼1cm LUL nodular density, prompting same-day chest CT, which confirmed a solitary ∼1-cm partsolid/ground-glass-predominant nodule suspicious for malignancy(image below) and recommended PET/CT. In October 2025, the PET/CT scan showed abnormal uptake confined to the lesion, without evidence of mediastinal or distant avidity. Robotic-assisted bronchoscopy with transbronchial biopsies, brushings, lavage, and EBUS (10/24/2025) was performed safely. Initial pathology was “atypical”; external expert review (11/03/2025) confirmed well-differentiated nonmucinous adenocarcinoma with lepidic growth. With a 7-8 mm solid (invasive) component and no radiographic nodal disease, the staging was cT1aN0M0. Multidisciplinary planning focused on anatomic segmentectomy versus stereotactic body radiotherapy (SBRT) pending pulmonary function testing and patient preference. Discussion This case highlights that the growth of the solid component, rather than total nodule size, should trigger tissue diagnosis—even when kinetics are indolent. The ED CXR served as the catalyst that restarted evaluation and led to timely confirmation. Despite a history of bladder cancer, the long-standing subsolid morphology and lepidic histology favored a new primary lung adenocarcinoma over metastasis. Robotic bronchoscopy provided a minimally invasive pathway to diagnosis in a small peripheral lesion. This case underscores that in thoracic oncology and interventional pulmonology practice, persistent, enlarging part-solid nodules—especially those with a solid component ≥6-8 mm—should prompt definitive evaluation, as early diagnosis enables curative-intent management with segmentectomy or SBRT at stage IA. This abstract is funded by: None
Saravanan et al. (2026) studied this question.