The contact length between the tumor contour and the lung on computed tomography is a risk factor for pleural recurrence after complete resection of thymoma

Objective Among the perioperative findings which included patient characteristics and imaging, surgical, and pathological findings of the tumor, the risk factors for pleural recurrence (PR) after complete resection of thymoma were explored. Methods Fifty-three patients with Masaoka stage I to III thymoma who underwent complete resection, and five patients with stage IVa disease accompanied with pleural dissemination were analyzed. In these cohorts, the patients were divided into a non-recurrence (NR) group, PR group and stage IVa group. The maximum tumor diameter (TD) and the contact length between the tumor contour and the lung (CLTL) were measured at the maximum section of the tumor on axial computed tomography. A multivariate analysis including gender, age, TD, CLTL, tumor adhesion to the lung, Masaoka stage, and WHO histological type was performed to estimate risk factors for PR. Results The median follow-up period was 76.9 months. PR developed in six patients. The mean TDs were 44 mm in the NR group, 62 mm in the PR group and 73 mm in the stage IVa group, respectively. The mean CLTLs were 47, 90 and 96 mm, respectively. The CLTLs of the PR group were significantly longer than those of the NR group ( p