Grading Systems for Nasal Polyps
The most widely accepted method for grading nasal polyps is using a standardized endoscopic scoring system such as the Lund-Kennedy scale or the 0-4 polyp grading scale, which evaluates polyp size and extent within the nasal cavity. 1
Common Nasal Polyp Grading Systems
Standard 0-4 Polyp Grading Scale
This is one of the most commonly used systems in clinical trials and practice:
- Grade 0: No visible nasal polyps 1
- Grade 1: Small polyps in the middle meatus, not reaching below the inferior border of middle turbinate 1
- Grade 2: Polyps reaching below the lower border of the middle turbinate 1
- Grade 3: Large polyps reaching the lower border of the inferior turbinate or polyps medial to the middle turbinate 2
- Grade 4: Large polyps causing complete obstruction of the inferior nasal cavity 1, 2
Lund-Kennedy Endoscopic Scoring System
This system evaluates multiple parameters including:
- Polyps: Scored 0-2 for each side (0 = no polyps, 1 = polyps in middle meatus, 2 = polyps beyond middle meatus) 1
- Edema: Scored 0-2 1
- Discharge: Scored 0-2 1
- Scarring/adhesions: Scored 0-2 1
- Crusting: Scored 0-2 1
Total score ranges from 0-12, with higher scores indicating more severe disease 1.
Lund-Mackay CT Scoring System
While not strictly a polyp grading system, this is commonly used to evaluate the extent of sinus involvement:
- Each sinus group is scored 0-2 (0 = no abnormality, 1 = partial opacification, 2 = total opacification) 2
- The ostiomeatal complex is scored as 0 (not occluded) or 2 (occluded) 2
- Maximum score is 24 (12 per side) 2
Clinical Application of Nasal Polyp Grading
Endoscopic Examination Technique
- Perform nasal endoscopy after applying a topical decongestant and anesthetic to the nasal mucosa 1
- Examine key areas including the nasal cavity, middle meatus, uncinate process, and sphenoethmoidal recess 1
- To differentiate polyps from severely edematous mucosa, apply a topical vasoconstrictor - polyps will not shrink, unlike edematous mucosa 1
Diagnostic Considerations
- Direct visualization is best accomplished with nasal endoscopy, though anterior rhinoscopy using an otoscope or nasal speculum may suffice in some cases 1
- CT scanning should be reserved for cases requiring surgical planning, unilateral polyps, or when endoscopic evaluation is inadequate 3
- The presence of polyps significantly affects treatment management, particularly regarding corticosteroid therapy 3
Limitations and Considerations
- Different polyp grading systems are used across clinical trials, making direct comparison of outcomes challenging 4
- Current nasal polyp endoscopic scoring systems often do not correlate well with patient-reported outcome measures or olfactory function 5
- Polyp scores should be assessed bilaterally, with each side scored separately, then combined for a total score 1, 2
- The minimally important clinical difference for the modified Lund-Kennedy endoscopy scale is approximately 3 points on the 0-12 scale 1
Treatment Implications Based on Polyp Grading
- Mild polyps (Grade 1): Typically managed with intranasal corticosteroids alone 6
- Moderate to severe polyps (Grades 2-4): May require short courses of systemic corticosteroids in addition to intranasal corticosteroids 6, 7
- Extensive polyps with complete obstruction (Grade 4): Often require surgical intervention if medical management fails 7
Proper grading of nasal polyps is essential for standardized assessment, treatment planning, and monitoring response to therapy in patients with chronic rhinosinusitis with nasal polyps 1.