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What is The most common site of nasopharyngeal carcinoma is and explain in detail?
The commonest site of origin of nasopharyngeal carcinoma is fossa of Rosenmuller in the lateral wall of the nasopharynx.
Tumor can spread to the following areas:-

Cranium through foramen lacerum & ovale → cranial nerves involvement (III, IV, V, VI); facial pain, and ophthalmic symptoms.
Parapharyngeal space → cranial nerves (IX, X, XI, XII) involvement, Horner's syndrome, Trismus (Pterygoid muscle).
Retropharyngeal nodes → Neck pain & stiffness.
Eustachian tube → Serous OM.
Nose and orbit → Obstruction, epistaxis, proptosis.
Cervical nodes → Upper jugular and posterior triangle nodes enlargement.
Distant metastasis → Lung, liver, bone.
Middle ear → Rarely, tumor grows up the tube into the middle ear.