Recurrent prostatic adenocarcinoma with perineural spread to the lumbosacral plexus and sciatic nerve: comparing high resolution MRI with torso and endorectal coils and F-18 FDG and C-11 choline PET/CT.

We present a patient with unexplained sciatica (radiating pain down the leg) found to have recurrent prostate adenocarcinoma within the sciatic nerve. High resolution MRI, especially use of an endorectal coil, improved visualization of the perineural spread of the disease. We believe that perineural spread resulting in sciatic symptoms in patients with known prostate adenocarcinoma may be an under-recognized phenomenon. The use of non-invasive modalities, high resolution endorectal coil MRI, and C-11 choline PET/CT can assist in the diagnosis of these patients.