Lung adenocarcinoma without stromal invasion accompanied by spread through alveolar spaces: A case report

Abstract

IntroductionLung cancer presenting as ground-glass nodules (GGNs) with little consolidation is often diagnosed as noninvasive carcinoma. Increasing evidence suggests that sublobar lung resection, such as wedge resection, provides satisfactory long-term outcomes equivalent to those of lobectomy. Spread through alveolar spaces (STAS) is a reported risk factor for recurrence, especially when sublobar lung resection is applied. We herein report a rare case of a pure GGN that was histologically confirmed to be adenocarcinoma in situ (AIS) and associated STAS after limited resection. Case presentationA 67-year-old woman presented with an 8-mm pure GGN in S2 of the right upper lobe and a part-solid GGN in S8 of the right lower lobe. The clinical stages of these GGNs were TisN0M0 stage 0 and T1aN0M0 stage IA1, respectively. The patient underwent video-assisted thoracoscopic segmentectomies of S2 and S8. Histopathological examination of the resected specimens revealed minimally invasive adenocarcinoma in S8 and AIS in S2. Stromal invasion was not observed in the tumor located in S2, but a tumor cell cluster was found in the air space located away from the AIS lesion. Thus, the lesion was positive for STAS. ConclusionWe have reported a rare case of a pure GGN that was histologically STAS-positive, otherwise diagnosed as AIS after limited resection.