[Analysis of morphological characteristics of laryngeal tuberculosis based on electronic laryngoscopy and image-enhanced endoscopy]

Objective: To explore and summarize the morphological features of laryngeal tuberculosis under electronic laryngoscopy and image-enhanced endoscopy (i-scan). Methods: A retrospective analysis was conducted on the data of 31 patients diagnosed with laryngeal tuberculosis at the Second Affiliated Hospital of Zhejiang University School of Medicine from January 2014 to June 2024, encompassing the morphological features of electronic laryngoscopy and i-scan endoscopy, histopathological features, and supplementary clinical examination results. Descriptive statistical methods were employed for the analysis. Results: Thirty-one patients were diagnosed with laryngeal tuberculosis, including 25 males and 6 females, aged from 21 to 84 years old, with an average age of 57 years old, and the disease course was from 1 to 12 months with an average of 3 months. The clinical symptoms included hoarseness in 27 cases, foreign body sensation in the pharynx in 2 cases, and sore throat in 2 cases. Twenty-six cases involved a single site, including 24 cases of the vocal cords, 1 case of the ventricular bands, and 1 case of the epiglottis; 5 cases involved multiple sites, including 2 cases of the vocal cords and the interarytenoid area, 2 cases of the aryepiglottic fold and the epiglottis, and 1 case of the aryepiglottic fold, the ventricular bands and the epiglottis. Eighteen patients showed a single morphology type under electronic laryngoscopy, including 4 cases of the edematous exudative type, 5 cases of the ulcerative type, and 9 cases of the granulation hyperplasia type. Edema, ulcer, and granulation hyperplasia can coexist and transit between each other. A total of 13 cases presented with two or more morphological types, with the edematous exudative type, the ulcerative type, and the granulation hyperplasia type occurred 7, 9, and 10 times respectively. Twenty-two patients had active or chronic pulmonary tuberculosis, while 9 patients had normal lung imaging. The laryngeal tissue biopsy pathology of 21 patients was chronic granuloma, and 10 patients were chronic granuloma with caseous necrosis; among them, 19 cases completed the Ziel-Neelsen staining (7 cases were positive for acid-fast bacilli), and 3 cases completed the polymerase chain reaction (PCR) (All were positive). Twenty cases completed the T-cell assay for tuberculosis infection (19 cases were positive), 15 cases completed the sputum smear (6 cases were positive), 18 cases were tested for antinuclear antibody (6 cases were positive), and 14 cases completed the erythrocyte sedimentation rate (4 cases were positive). Six patients underwent i-scan examination. In cases of ulcerative laryngeal tuberculosis without granulation hyperplasia in the surrounding tissues, i-scan revealed an abundance of abundant slightly thickened and tortuous oblique and dendritic blood vessels around the ulcer. If the pseudomembrane in the deep ulcer was thick, the blood vessel shadow was not visible. In shallow ulcers, there were areas of deep congestion and scattered dot-shaped blood vessel shadowst with uneven distribution; in cases of laryngeal tuberculosis with coexistence of the edematous exudative type and the granuloma type, i-scan visualized laryngeal cord edema with white exudates on the surface. Beneath the laryngeal cord exudates, there were scattered dot-shaped and irregularly distorted linear blood vessel shadows with uneven distribution, and tortuous, oblique, and dendritic blood vessels were observed around the lesion. In granuloma-type laryngeal tuberculosis, i-scan demonstrated that the area of granulation hyperplasia around the ulcer focus was significantly congested, characterized by scattered thick dot-shaped blood vessel shadows and irregularly distorted linear blood vessel shadows. Conclusions: Laryngeal tuberculosis presents as the edematous exudative type, the ulcerative type, and the granulation hyperplasia type under electronic laryngoscopy, and these types can coexist and interact. i-scan endoscopy can reveal detailed microvascular morphology and other subtle morphological characteristics. The identification and summary of these morphological characteristics are beneficial for the early detection and diagnosis of laryngeal tuberculosis.