<prompt> Which parotid tumor spreads along nerve sheath ?Pleomorphic adenomaMucoepidermoid carcinomaAdenoid cystic carcinomaWahins tumor  <response>: Adenoid cystic carcinoma has got high affinity for perineural spreadboth axially and circumferentially;antegrade and retrograde fashion along mandibular and maxillary divisions of trigeminal common and facial nerve .It infiltrates nerve more proximally for long distance. Tumor may reach Gasserian trigeminal ganglion ,pterygopalatine ganglion and cavernous sinus SRB,5th,417 . 