Cystic lymphangioma is a rare benign congenital malformation of the lymphatic system. It usually presents in childhood and rarely in young adults. Its management lacks consensus, and its prognosis varies depending on the location. We report a case of cervical cystic lymphangioma in a young adult with chronic left lateral cervical swelling. Examination revealed a high jugulocarotid swelling, non-pulsatile, and transilluminable. Radiographic exploration suggested a cystic lymphangioma. Histopathology confirmed the diagnosis. The patient underwent a sclerotherapy session, followed by surgical excision. Our case illustrates a rare presentation of cervical cystic lymphangioma in a young adult and aims to increase awareness of this rare entity and provide literature insights into its diagnosis and treatment in adult patients.

Thyroglossal duct cyst (TGDC) is a congenital neck malformation, with a rate of approximately 7% in paediatric patients. TGDC is rarely detected in infants aged younger than 1 year. Even though TGDC is histologically benign, it is associated with preterm delivery or sudden infant death due to airway obstruction, with a mortality rate of 30% to 40%. We report a rare case of a neonate who presented with a large left lateral neck mass. At 7 to 8 months of gestation, magnetic resonance imaging of the foetal neck showed that there was a high possibility of a cervical cystic lymphangioma. The patient had normal vital signs and was afebrile. She was immediately transferred to our Ear, Nose, and Throat Department for further diagnosis and treatment. A computed tomography scan confirmed a large cystic mass that was positioned against a thyroglossal duct. Excision of the mass in the left neck was performed under general anaesthesia without resecting part of the hyoid bone. A histopathological examination confirmed the diagnosis of a TGDC. Follow-up at 1 year showed no recurrence.