Recurrent laryngeal leukoplakia in a cook occupationally exposed to cooking oil fumes: a case report.

Background: This study reports a case of recurrent laryngeal leukoplakia, a precancerous lesion, in a female cook with long-term occupational exposure to cooking oil fumes. In 2022, the Korean Epidemiological Investigation and Evaluation Committee determined that substantial scientific evidence supported the work-relatedness of the case. Case presentation: A 55-year-old woman working as a cook in group-catering facilities in long-term care hospitals and general hospitals was referred to an otolaryngology clinic after an abnormal laryngeal finding was incidentally detected during routine upper gastrointestinal endoscopy in April 2018. Subsequent laryngoscopy revealed granulation tissue of the left vocal fold. Histopathological examination following laryngeal microsurgery confirmed high-grade dysplasia, leading to a diagnosis of left vocal fold leukoplakia, and the lesion was excised. During follow-up, persistent voice changes and recurrence of the lesion were identified, and repeat excision again demonstrated low- and high-grade dysplasia. The patient had worked as a cook for approximately 14.6 years and routinely performed oil-intensive cooking tasks, including frying, grilling, stir-frying, and battered-dish preparation, for approximately 2-4.5 hours per day. She reported insufficient ventilation during heavy fume generation. She had no history of smoking, passive smoking from her spouse, alcohol consumption, vocal abuse, gastroesophageal reflux disease, or mechanical trauma to the larynx. Conclusions: This case suggests a possible occupational contribution of repeated intermittent exposure to cooking oil fumes and irritant aldehydes to recurrent laryngeal precancerous lesions among cooks. However, because direct historical exposure measurements were unavailable and this is a single case report, definitive causality cannot be established. Improvement of workplace ventilation and other exposure-control measures should be considered, and further studies with direct exposure assessment are needed.