Salivary duct carcinoma with perineural spread to facial canal: F-18 FDG PET/CT detection.

Salivary duct carcinoma is a highly aggressive malignancy targeting predominantly the parotid gland. It frequently involves the extracranial portion of the facial nerve and has a propensity to metastasize through the temporal bone via perineural spread. The authors present a case of treated parotid malignancy with F-18 FDG PET/CT detecting abnormal radiotracer uptake within the facial canal from perineural tumor recurrence. The positive PET/CT finding was confirmed by subsequent MR examination. Postradiation PET/CT surveillance showed resolution of the perineural metastasis with unfortunate distant ischial bone dissemination.