White Crusted Lesions at Risk of Vocal Cord Cancer

Vocal cord leukokeratosis, adult laryngeal papillomas and chronic hypertrophic laryngitis are considered as laryngeal precancerous lesions. Leukokeratosis is a clinical description. It refers to an increase in the epithelial or keratotic layer of the vocal cord due to abnormal epithelial hypertrophy or dysplasia. The lesion may occur in part or all of the vocal cord and may vary greatly in depth. Because the medical history, aetiology, causes and depth of involvement are different, treatment and prognosis also differ. The data of Ma and colleagues' series of 360 leukokeratosis patients treated within one year are as follows:

• 332 male and 28 female patients
• Age range 18-78 (average 48)
• Symptoms: Hoarseness 91%, foreign body sensation 9%; duration 1-36 months
• 60 cases bilateral, 29 cases located in the anterior commissure
• 21 patients were treated conservatively (phonation restriction, oral anti-inflammatory drugs, oral antacids and budesonide) and monthly follow-ups were performed until the lesion disappeared.
• Surgically treated 339 patients; submucosal cordectomy for leukokeratosis opposite the main lesion, mucosal slicing and scanning for leukokeratosis with Type II and III sulcus, and partial subligamental or transmucular cordectomy for leukokeratosis of unknown cause. Follow-up was monthly in the first year and bimonthly in the second year. Based on history, video images and microscopic morphology, lesions were divided into 4 groups:

Type I - inflammatory leukoplakia (#21, 6%): Bilateral, white membrane-like appearance, 2 weeks to 2 months history; associated with URI, excessive coughing, heavy alcohol use, excessive voice use, sudden onset and marked hoarseness. Symptoms improve significantly with about 2 months of conservative treatment.

Type II - friction polyp (#76, 21%): characterised by unilateral, localised thickening of the mucosa opposite the polyp.

Type III - sulcus vocalis (#68, 19%): Associated with a Type II or III sulcus vocalis on the same side. These vocal cords have grooves of varying depth and length, with the base of the lesions being verrucose, angled or sloping below the groove.

Type IV - simple leucokeratosis (#195, 54%): May be confined to the mucosa or extend into the submucosa. May appear patchy, verrucous or papillary. May be limited or involve the entire cord.

All cases with type I lesions healed within 2 months with conservative methods. Type II lesions were treated with submucosal resection and Type III lesions were treated with mucosal slicing. Among type IV lesions, subligamental cordectomy was performed in 162 cases and transmucular cordectomy in 33 cases. Thirty-one cases required reoperation after 3-12 months. The cure rate with single surgery was 91%. The overall cancer rate was 6.1% in all cases (22/360); 6.5% in surgical cases (22/339); 0% in Type I-III lesions; and 11% in Type IV lesions (22/195). Mucosal congestion lasting approximately one month and pseudomembranous material lasting approximately two months after surgery were observed in Type II and III lesions. It took about two months for the mucosal wave to return to its best condition. Type IV lesions can take up to six months to reach their final state.

When the pathological specimens were evaluated according to the WHO classification of intraepithelial vocal cord lesions, simple hyperplasia was seen in 20%, mild dysplasia in 42%, moderate dysplasia in 29%, severe dysplasia in 7% and carcinoma in situ in 3% of the cases after the first operation. More than half of the cases with severe dysplasia (13/22) were diagnosed as squamous cell carcinoma after the second operation.