MRI stages it: the fossa of Rosenmüller origin, parapharyngeal and skull base extension, perineural spread through the foramina to the cavernous sinus, and the retropharyngeal and cervical nodes that are almost always involved.
Orient first
- Endemic in southern China and parts of Southeast Asia and the Indian north-east.
- Skull base invasion (clivus, pterygoid bases) and intracranial or cranial nerve involvement raise the T-stage (verify edition).
- Retropharyngeal nodes are the first echelon; nodal disease is frequent even with small primaries.
Acquire the study
- Axial and coronal T1, T2 fat-saturated, DWI, post-gadolinium fat-saturated T1 in three planes.
The manoeuvre
- Axial T2: asymmetric mass at the fossa of Rosenmüller; parapharyngeal fat invasion.
- T1: marrow signal loss in the clivus and pterygoid bases.
- Post-contrast coronal T1: foramen ovale and rotundum, Meckel cave and cavernous sinus.
- Nodes: lateral retropharyngeal (≥ 5 mm short axis — verify), levels II–V.
What confirms it
- Biopsy-proven nasopharyngeal carcinoma with MRI stage by edition.
What licenses you to exclude it
- Symmetric nasopharynx with intact deep fat and marrow on MRI makes a significant tumour unlikely; endoscopy with biopsy decides.
The classic misread
- Calling asymmetric adenoidal lymphoid tissue in a young adult carcinoma — look for invasion of deep fat and marrow.