Squamous Cell Carcinoma Arising in a Zenker's Diverticulum.

Squamous cell carcinoma (SCC) developing in a Zenker's diverticulum (ZD) is an uncommon condition. The preferred treatment for SCC in the pharyngeal pouch is complete diverticulum resection. Only histopathological evaluation of the pouch can rule out SCC. Here, we present a case of a 62-year-old male patient, who was evaluated for repeated episodes of aspiration and dysphagia, and diagnosed to have a large ZD, the patient underwent Zenker's diverticulectomy with cricopharyngeal myotomy with wide margins due to clinically suspicious specimen. Histopathological examination revealed well-differentiated SCC arising within ZD, involving the whole thickness of the wall and almost touching the serosa (1 mm). The patient developed metastatic lung nodule on PET-CT, so metastatic lung nodule was excised with video-assisted thoracoscopic surgery (VATS), and chemotherapy and immunotherapy were given. On follow-up imaging patient is tumor-free to date, two years after the surgery. The occurrence of synchronous or metachronous lung cancer makes it one of the rarest cases.