Head and Neck Cancer - 60 year old male

History
60 year old male, with a history of squamous cell carcinoma of the right posterior oropharynx & right neck, underwent a right modified neck dissection and radiation therapy in 96. He complained of a new onset of left-sided throat pain.

Imaging Findings



The PET•CT scan revealed a focal area of intense FDG uptake in the left retromolar trigone area, which was obscured on the CT portion of the exam by an artifact from metallic dental implants. Also, there was focal intense FDG uptake in the right lung apex corresponding to the area of “scarring” identified on the patient's recent CT scan.

Pathology

Biopsy of the left retromolar trigone revealed a well to moderately differentiated squamous cell carcinoma, and analysis of the right upper lobe wedge resection revealed a poorly-differentiated adenocarcinoma.

Discussion
The PET•CT scan revealed not only where the primary tumor was, but also that he had evidence for a second primary malignancy in his right lung apex.

This case demonstrates two advantages of combined PET•CT . The first is the ability to detect precisely where an area of recurrence is, even when it is obscured by a CT artifact, as in this case. The second is the ability to survey the entire body and have the potential of detecting small metastatic lesions or, as in this case, an early second lung primary adenocarcinoma.