CT characteristics of solitary pulmonary capillary hemangioma versus lung adenocarcinoma

Abstract Background Solitary pulmonary capillary hemangioma is an underrecognized rare benign disease that can radiologically mimic lung adenocarcinoma. This study aims to demonstrate radiologic features of SPCH and compare characteristics between SPCH and lung adenocarcinoma. Materials and methods This retrospective study included all histologically confirmed SPCH cases from our institution between July 2015 and December 2024. For comparison, lung adenocarcinomas matched to SPCH by nodule consistency and size within the same period were included. Two chest radiologists independently assessed each nodule’s consistency, size, location, and morphologic signs, with group comparisons by χ² or Fisher exact tests and Mann-Whitney U tests. Results The study comprised 44 SPCH patients (28 women, 63.6%; median age, 44.5 years [IQR, 37.0–55.2]) and 352 adenocarcinoma patients (202 women, 57.4%; median age, 58 years [IQR,50.0–65.0]). SPCH can manifest as nonsolid (12/44, 27.3%), part-solid (8/44, 18.2%) and solid nodules (24/44, 54.5%). SPCH shared multiple features with lung adenocarcinoma in nonsolid and part-solid nodules. However, in solid nodules, SPCH were more likely to occur in lower lobes (21/24, [87.5%] vs. 71/192 [37%]), more often presented with air bronchogram (18/24 [75.0%] vs. 26/192 [13.5%]), and lacked spiculation (2/24 [8.3%] vs. 169/192, [88.0%]) and pleural retraction (5/24, [20.8%] vs. 131/192, [68.2%]) (all P < 0.001). Five SPCH cases (5/44, 11.3%) demonstrated atypical bronchus lucency, while 3 cases (3/44, 6.8%) showed perivascular lucency. Conclusion Solid SPCHs are distinguished from lung adenocarcinomas by a predilection for peripheral lower-lobe location, frequent air bronchograms, and near-absence of spiculation or pleural retraction. Recognition of atypical bronchus lucency and perivascular lucency signs may further aid differentiation.