Pulmonary and pleural schwannomas: a 20-year multicampus retrospective cohort study

Background Pulmonary and pleural schwannomas are rare nerve sheath tumours that can mimic lung malignancy on CT and positron emission tomography-CT (PET-CT).Methods We conducted a multicentre retrospective cohort study of adults with pathology-confirmed pulmonary, pleural or pleural-adjacent schwannomas seen across Mayo Clinic sites from 1 January 2005 to 1 January 2025. Cases were identified through International Classification of Diseases extraction, large language model-assisted document screening, pathology confirmation and manual anatomical review. Outcomes were reabstracted through 31 July 2026. Healthcare-system case frequency was calculated using unique adults receiving care as the denominator.Results 31 adults met inclusion criteria; 24 (77%) were women, 25 lesions (81%) were incidental and 23 (74%) were right-sided. Among 18 patients who underwent PET-CT, 16 lesions (89%) were fluorodeoxyglucose (FDG) avid (median maximum standardised uptake value 7.0, IQR 3.6–8.3). Pathology showed 29 benign (94%) and 2 malignant (6%) schwannomas. Initial management was open resection in 13, video-assisted thoracoscopic surgery or robotic resection in 11, surveillance in 6 and radiation alone in 1. Follow-up was available for 24 patients (median 43 months, IQR 23–90). Five of 24 assessable patients had a 30-day complication. Two patients presented with recurrent tumours after prior resection; no further postoperative recurrence was documented among 19 with assessable follow-up. The 20-year case frequency was 6.08 per 1 000 000 adults receiving care.Conclusions FDG avidity was common but non-specific, supporting tissue confirmation when imaging raises concern for malignancy. The healthcare-system frequency should not be interpreted as population incidence, and the small surveillance subgroup precludes firm conclusions about non-operative management.