Thyroid Cancer - 70 year-old male

History
70 year-old male with a recent biopsy of a right neck mass, positive for poorly differentiated squamous cell carcinoma. Initial staging CT of the neck failed to show a muscosal primary.

Initial PET/CT Findings
Large area of intense FDG uptake in the right neck corresponding to large nodal mass. In addition, primary mucosal lesion with focal intense FDG uptake without a definite CT correlative abnormality.

Pathology
Part 1: Wide base of tongue invasive squamous cell carcinoma, moderate to poorly differentiated.
Part 2: Right oropharynx squamous cell carcinoma moderate to poorly differentiated.

Follow up PET/CT Findings
No evidence for FDG-avid malignancy. The abnormalities previously noted are not present on the current study.

Treatment
Resection of primary mucosal lesion and radical right neck dissection. External beam radiation and chemotherapy.

Discussion
This is a very good illustration of the ability of PET/CT to identify primary head and neck malignancies when they might not be detected by other imaging modalities. This patient initially had a CT scan of the neck after feeling an enlarged mass and failing a trial of antibiotics. The CT easily identified the abnormal necrotic node, but did not definitively identify the mucosal primary in the right oropharynx. In fact, it suggested that the primary mucosal lesion was on the left side. After an exam by an otolaryngologist and a FNA of the right neck mass, which was positive for metastatic squamous cell carcinoma, the patient was sent for PET/CT, which has become standard protocol prior to patients going to surgery.

PET/CT identified both the metastatic lesion as well as the primary mucosal lesion. The follow up PET/CT after resection, chemo and radiation was negative. Two additional PET/CT studies have remained negative.

Courtesy of
Todd M. Blodgett, MD, University of Pittsburgh Medical Center.