Poorly differentiated adenocarcinoma arising from a cervical bronchial cyst.

Bronchogenic cysts with malignant change are rarely reported. We describe a case of poorly differentiated adenocarcinoma arising from a cervical bronchial cyst in a patient presenting with a thyroid mass, cervical lymphadenopathy, and initial biopsy suggestive of papillary thyroid carcinoma. The clinical presentation, intraoperative findings, radiographic images, and pathology slides are presented. To our knowledge, this is the first report of a poorly differentiated adenocarcinoma arising from a bronchial cyst in the cervical region.