The diagnosis of pulmonary carcinoid using intraoperative fine-needle aspiration cytology: A case report.

Introduction and importance: Surgeons often need to make intraoperative decisions regarding resection of lung tumors without a preoperative pathological diagnosis. Although intraoperative fine-needle aspiration cytology (FNAC) often provides useful diagnostic information, literatures on its usefulness in pulmonary carcinoids is limited.

Case presentation: A medical chest radiograph revealed an abnormal shadow in the right upper lung field of a 45-year-old Japanese man. Chest computed tomography (CT) revealed a solid 2.5-cm nodule in the right upper lobe. Follow-up CT for one year showed that the tumor size had increased. In case of lung cancer, it was clinically detected to be resectable at stage IA3 with clinical T1cN0M0. Intraoperative FNAC confirmed a specific appearance, and a diagnosis of carcinoid was made. Right upper lobectomy and mediastinal lymph node dissection were performed via video-assisted thoracic surgery. The final histopathological diagnosis was a typical carcinoid with positive chromogranin A, synaptophysin, and CD56, a Ki-67 labeling index of 5 %, and pathological stage IA3 with T1cN0M0, which was consistent with the intraoperative diagnosis.

Clinical discussion: This is the first report describing the diagnosis of pulmonary carcinoid by intraoperative FNAC with the publication of characteristic pathological images, demonstrating the usefulness of intraoperative FNAC.

Conclusion: Intraoperative FNAC may be a low-risk and short-duration procedure for diagnosing pulmonary carcinoids.