Primary malignant peripheral nerve sheath tumour of the lung: incidental detection on chest imaging performed for unrelated trauma.

SummaryWe present a rare case of primary malignant peripheral nerve sheath tumour (MPNST) of the lung in an elderly male, incidentally detected during imaging for unrelated trauma. The patient was asymptomatic and had no features of neurofibromatosis or prior radiation exposure. Chest radiography revealed a solitary pulmonary lesion, and further evaluation with PET-CT and biopsy confirmed a high-grade spindle cell sarcoma consistent with MPNST. He underwent curative resection via video-assisted thoracoscopic surgery-guided left upper lobectomy. Histopathology showed classic features of MPNST with loss of H3K27me3. The patient had an uneventful postoperative recovery and remains disease-free on follow-up. This case highlights the diagnostic challenges of intrapulmonary MPNST and underscores the importance of considering rare sarcomas in the differential diagnosis of solitary pulmonary lesions. Timely surgical resection in selected cases may offer excellent outcomes despite the tumour's aggressive biology.