Classification of nasal polyposis

Introduction:

It is rather important to classify and stage nasal polyposis in order to decide the magnitude of the disease and to decide on the optimal management modality. Various methods of classification and categorization of nasal polypi have been attempted. These methods can be classified into:

1. Questionnaire based categorization
2. CT based grading system
3. Nasal endoscopic scoring system
4. Nasal functional scoring system

The fact that numerous scoring system have been devised indicate that none of them are fool proof.

Questionnaire based categorization:

Disease based questionnaires are more sensitive than very general quality of life questionnaires. Classically disease specific questionnaire should contain the following parameters:

a. Assessment of facial pain

b. Nasal blockage

c. Olfaction

d. Nasal discharge

e. Post nasal drip

These questionnaires are generally used to assess the patient's response to a treatment modality over a period of time. Most important bothersome complaint of patients with nasal polyposis is nasal blockage and impaired olfaction. None of the questionaires designed so far are specific for nasal polyposis.

1. Rhinosinusitis outcome measure 31- This questionnaire contains 31 questions spread over six domains (subheadings). The patient is given this questionnaire and is expected to score each item according to its severity and importance to the patient.
2. Sinunasal outcome test 20 – This is actually a modification of Rhinosinusitis outcome measure 31. This is slightly easier to complete. Ironically this questionnaire does not include questions on nasal blockage or sense of smell.
3. Rhinosinusitis disability index – This index includes 30 questions relating to nose and sinus symptoms. These symptoms pertain to limitations on daily functioning of the individual.
4. Chronic sinusitis survey index – This includes duration based 6 questions. The questions include symptoms like pain, congestion, drainage and medication usage.
5. Rhinitis utility symptom index – This is a 10 question survey which concentrates on severity of nasal obstruction, rhinorrhoea, sneezing, itching and watery eyes.
6. RhinoQol – This is sinusitis specific questionnaire measuring the symptom frequency, bothersomeness and can be used to evaluate both acute and chronic rhinosinusitis
7. Visual analogue scale – This is used for assessing discrete symptoms. The patients can mark on a line the severity of symptoms. A scale of 5 has been known to affect the quality of life of the patient.
8. Sinonasal questionnaire – This is a 5 item questionnaire with a scale of 0-3. Higher scores indicates more frequent symptoms.

Grading system dependent on CT scan findings:

Lund Mackay scoring system is the most widely used grading system for chronic rhinosinusitis. This scoring system consists of a scale of 0-2 dependent on the absence, partial or complete opacification of the sinus system and the osteomeatal complex. This scoring system derives a maximum score of 12 per side.

Table illustrating Lund Mackay scoring system

Zinreich modification of Lund Mackay scoring system:

This modification proposed by Zinreich allows more discrimination in grading sinusitis.

This system scores each sinus involvement over a scale of 0-5, and the osteomeatal complex involvement into 1 and 2.

Score 0 – 0% opacity of sinuses

Score 1 – 25% opacification of the affected sinus

Score 2 – 26-50% opacification of affected sinus

Score 3 – 51-75% opacification of affected sinus

Score 4 – 76 – 99% opacification of affected sinus

Score 5 – 100% opacification of affected sinus

Lund Kennedy scoring system helps in categorizing nasal polyposis. This scoring system involves meticulous endoscopy study of of nose and paranasal sinuses. This scoring system can also be used to study post operative results following endoscopic sinus surgery.

1. Presence of polyp on left side – (0,1,2,3)
2. Presence of polyp on right side – (0,1,2,3)
3. Edema left (0,1,2)
4. Edema right (0,1,2)
5. Discharge left (0,1,2)
6. Discharge right (0,1,2)

Post operative scoring system of Lund Kennedy:

1. Scarring, left (0,1,2)
2. Scarring right (0,1,2)
3. Crusting left (0,1,2)
4. Crusting right (0,1,2)

Hadley's clinical scoring system of nasal polyposis include categorization of nasal polypi in relation to their sizes. These have been subdivided into 4 stages.

Stage 0 – No visible nasal polyp

Stage 1 – Small amount of polypoidal tissue confined to the middle meatus

Stage 2 – Multiple polypi occupying the middle meatus

Stage 3 – Polypi extending beyond the middle meatus

Stage 4 – Polyp completely obstructing the nasal cavity

A modification of this system includes one more stage i.e. Stage 5 which includes polyp touching the floor of the nasal cavity.

Diagram showing the 5 stage clinical scoring system of nasal polypi

Histologic categorization:

In this system the nasal polypi has been categorized into eosinophilic and non eosinophilic. This is very relevant in deciding the optimal management modality. Eosinophilic nasal polyposis is considered to be more steroid responsive than that of non eosinophilic one.