CT-based diagnostic insights in a rare case of laryngeal tuberculosis

Abstract

INTRODUCTION In 2023 overall tuberculosis (TB) incidence rate was 134/100,000. Most TB cases reported in regions of South-East Asia (45%), least in Europe (2.1%) (World Health Organisation, 2024) disproportionately affecting males (Pape et al., 2024). TB incidence in Lithuania declined from 31.8 to 21.3 per 100,000 in years 2019 - 2023 (Nacionalinis Visuomenės Sveikatos Centras Prie Sveikatos Apsaugos Ministerijos, 2023) . A lower proportion of extrapulmonary TB was seen in Eastern Europe (17.4%) and Southern Europe (29.6%) compared with Western (35.7%) and Northern Europe (41.8%) (Hayward et al., 2021). RESEARCH AND FINDINGS: A 49 y.o. male presented with cough, unintentional weight loss, fever, difficulty swallowing and throat pain. Patient hospitalized in ENT for suspected laryngeal carcinoma. Enlarged left neck lymph node detected. Laryngoscopy revealed increased mucus, edematous epiglottis, and ulceration on the right laryngeal surface and aryepiglottic fold, suspecting laryngeal carcinoma, risk factors including smoking and alcohol use, unemployment. Neck CT scan revealed soft tissues thickening and contrast enhanced infiltration of epiglottis, glossoepiglottic, pharyngoepiglottic, and aryepiglottic folds, and the right vestibular fold raised suspicion of granulomatous disease (Fig.1). Chest X-rays were performed, showing typical TB signs, AFB test was positive, and culture confirmed Mycobacterium tuberculosis. Laryngeal biopsy excluded malignancy and showed granulomatous inflammation due to tuberculosis. DISCUSSION CT is superior to laryngoscopy in laryngeal TB diagnostics. CT patterns include diffuse thickening with enhancement, especially pronounced mucosal thickening, polypoid or fungating mass, and fluid collection, also bilateral enhancement with variable paralaryngeal fat infiltration, calcifications in necrotic lymph nodes, smooth or irregular, swollen epiglottis can be present (Alshoabi et al., 2022).Differentiating laryngeal TB from carcinosis, sarcoidosis, granulomatosis can be done by identifying characteristic features in CT as shown in table 1.