Rhinology and Anterior Skull Base
Core concepts
Build a systematic endoscopic anatomy of the nasal cavity: inferior, middle, and superior turbinates; the middle meatus as the drainage site of frontal, maxillary, and anterior ethmoid sinuses; the sphenoethmoidal recess for the sphenoid. Know the ostiomeatal complex as the functional unit whose obstruction drives chronic rhinosinusitis. Distinguish CRSwNP (bilateral polyps, type 2 inflammation, often asthma/aspirin sensitivity - AERD) from CRSsNP and from unilateral lesions (inverting papilloma, esthesioneuroblastoma, malignancy). Understand the anterior skull base landmarks: cribriform plate, fovea ethmoidalis, lateral lamella (thinnest, highest iatrogenic CSF leak risk), and the relationship of the sphenoid to the internal carotid and optic nerve.
Traps
Unilateral polyposis or bleeding in an adult is not simple CRS until proven otherwise - image and biopsy. A "safe" middle meatus is not safe if the lateral lamella is asymmetric. Allergy testing does not replace imaging for unilateral disease. Beware questions mixing epistaxis causes (Little's area vs posterior/sphenopalatine) and management escalation.
Rule of thumb
For any unilateral nasal mass with bleeding or bone erosion, obtain CT/MRI and tissue diagnosis before any "polypectomy." For endoscopic sinus surgery, the lateral lamella and cribriform are the danger zones - stay lateral to the middle turbinate and respect the skull base slope.