Antral sign is seen in ?

Investigations of JNA Following investigations are used in JNA :- i) Soft tissue lateral film of nasopharynx :- shows soft tissue mass in the nasopharynx. ii) X-rays paranasal sinus and base of skull :- findings have been explained in previous explanation. iii) CT scan of head with contrast :- is the investigation of choice. It shows the extent of tumour, bony destruction, or displacement. Anterior bowing of the posterior wall of maxillary sinus (antral sign or Hohnan-Miller sign) is pathgnomonic of JNA. iv) MR1 complementory to CT when soft tissue extensions are present intracranially, in infratemporal foss or in orbit. v) Carotid angiography :- shows extension of tumor, its vascularity and feeding vessels. Biopsy should be avoided as it can cause severe bleeding.