Abstract

A 1-week-old female infant presented with a transilluminating neck lump that increased in size with crying. The presumptive diagnosis was lymphatic malformation, but imaging raised the possibility of an abscess or necrotic tumour. A biopsy revealed a likely developmental cyst with local inflammatory change. Microlaryngoscopy revealed a fourth branchial pouch sinus, which was cauterised. The sinus and neck lump resolved without need for further treatment.