Primary sarcomatoid carcinoma of the trachea: A case report and literature review.

Rationale: Primary sarcomatoid carcinoma of the trachea (PSCT) is a rare malignant tumor of the lower respiratory tract. Pathological types of tracheal sarcomatoid carcinoma (TSC)s include pleomorphic carcinomas, giant cell carcinomas, spindle cell carcinomas, pulmonoblastomas, and carcinosarcomas. At present, there are limited reports on PSCT, and pathologists lack sufficient knowledge about it.

Patient Concerns: Here, we report a case of malignant neoplasm involving the left posterior wall of the initial tracheal segment, characterized by atypical spindle cells and a small number of high-grade squamous intraepithelial neoplasia.

Diagnosis: Spindle-shaped cells were moderately heterotypic, with 8/10 nuclear divisions (high-magnification field), and no obvious inflammatory cell infiltration was observed in the interstitium. Squamous epithelial cells showed moderate-to-severe atypia with regional cytoplasmic transparency. Immunohistochemistry: Fusiform tumor cells expressed vimentin, epithelial markers were negative, the Ki-67 proliferation index was 40%, and epithelial markers were expressed in squamous intraepithelial neoplasia.

Interventions: After the biopsy diagnosis was confirmed, part of the tumor was removed by tracheoscopy under general anesthesia in the respiratory department of a superior hospital. A pathological diagnosis of TSC was made and local radiotherapy was performed.

Outcomes: As the tumor could not be completely cured, the patient experienced repeated coughing and shortness of breath and died of the disease 15 months later.

Lessons: Pathological morphology and immunohistochemical analyses deepen our understanding of the pathological features of TSC and provide a diagnostic reference for clinicians who will encounter such cases in the future.