Abstract:Objective This article reports a case of synchronous nasopharyngeal carcinoma, laryngeal carcinoma, and esophageal squamous cell carcinoma in situ. The possible mechanisms, diagnosis, and treatment strategies of multiple primary cancers of the head and neck were discussed based on the relevant literature. Methods The clinical data, diagnosis and treatment, and follow-up of the patient were retrospectively analyzed, and a literature review was conducted. Results The patient was a 65-year-old male.Gastroscopy and electronic nasopharyngolaryngoscopy revealed lesions in the nasopharynx, larynx, and esophagus. The patient underwent microscopic laser excision of the laryngeal lesions and biopsy of the nasopharyngeal lesion. Histopathological examination showed lymphoepithelial carcinoma of the nasopharynx, squamous cell carcinoma of the right ventricular fold, esophageal squamous cell carcinoma in situ, and a polyp of the left vocal fold. Following multidisciplinary discussion, chemoradiotherapy for the nasopharyngeal carcinoma was performed first, followed by systemic chemotherapy. During nearly 11 months of postoperative follow-up, the nasopharyngeal lesion was markedly reduced, and no obvious abnormalities were found at the original lesion sites in the larynx or esophagus. Conclusion Multiple primary cancers may occur in patients with head and neck tumors. Clinicians should improve their understanding of multiple primary cancers, attach importance to systematic evaluation of multiple sites, reduce missed diagnoses, and optimize diagnosis and treatment strategies.