Superior sulcus tumor with vertebral invasion following initial diagnosis of cavitary lung disease: a case report.

Background: Superior sulcus tumors represent a rare and aggressive subset of non-small cell lung cancer characterized by early invasion of adjacent osseous, vascular, and neural structures. Diagnosis may be challenging when clinical and radiographic features overlap with infectious etiologies, particularly in the setting of cavitary lung disease. The increasing prevalence of nontuberculous mycobacterial pulmonary infection further complicates this distinction and may delay recognition of underlying malignancy. This report aims to highlight the diagnostic challenges posed by cavitary pulmonary lesions with confirmed infection and to describe the multidisciplinary management of a superior sulcus tumor with vertebral invasion. Case Description: A 48-year-old woman with a history of tobacco use initially presented with a cavitary right upper lobe lesion and microbiologically confirmed nontuberculous mycobacterial infection. Initial management focused on antimicrobial therapy, with partial radiographic improvement. Persistent symptoms and evolving imaging findings prompted further evaluation. Robotic navigational bronchoscopy revealed a locally advanced superior sulcus adenocarcinoma with invasion of the T3 and T4 vertebral bodies and neural foramina. Invasive mediastinal staging by endobronchial ultrasound confirmed absence of nodal involvement. The patient staged as cT4N0 disease and underwent induction chemoradiotherapy with carboplatin, pemetrexed, and 60 Gy of radiation, achieving a significant metabolic and radiographic response. She subsequently underwent multidisciplinary en bloc resection, including right upper lobectomy, mediastinal lymphadenectomy, and partial T3 corpectomy with T2 to T4 spinal stabilization. The postoperative course was uneventful. Final pathology demonstrated a complete pathologic response with negative margins and no nodal involvement (ypT0N0). Conclusions: This case highlights the diagnostic pitfalls associated with cavitary pulmonary lesions in high-risk patients and emphasizes the importance of maintaining suspicion for malignancy despite microbiologic confirmation of infection. It also underscores the role of multidisciplinary reassessment and induction therapy in facilitating successful resection of selected locally advanced superior sulcus tumors.