Cystic hygroma presenting as paediatric stridor

Cystic hygroma, a fluid-filled lymphatic lesion, commonly presents in the head and neck but can occur anywhere. Paediatric stridor is a critical emergency demanding precise diagnosis and immediate airway intervention. We report the case of a 2-year-old male child presenting with a 7-day history of dysphagia and stridor, accompanied by high-grade fever, left neck swelling, and torticollis. Examination revealed a posterior pharyngeal wall bulge. Initial impression was retropharyngeal abscess, necessitating emergency tracheostomy for airway compromise. Midline aspiration yielded straw-coloured fluid, and histopathological examination confirmed cystic hygroma. Postoperative MRI revealed a large (9.6 x 7.7 x 3.4 cm) hyperintense cystic lesion with septations, extending from the oropharynx to the upper mediastinum, encasing vital structures. The patient subsequently underwent four cycles of sclerotherapy with intra-lesional bleomycin. This case highlights the challenges in diagnosing atypical causes of paediatric stridor. Sclerotherapy with bleomycin proved to be a highly effective treatment for this extensive cystic hygroma, demonstrating its superiority over surgical options due to lower associated risks and favourable outcomes.