Human Coenurosis Caused by Taenia multiceps Mimicking a Thyroglossal Duct Cyst in a Child: A Case Report.

BACKGROUND: Coenurosis is a rare zoonotic parasitic infection in humans, caused by the larval stage (coenurus) of Multiceps multiceps, typically acquired through ingestion of ova shed in the feces of infected canids. While the central nervous system is the most commonly affected site, extracranial involvement, particularly in the head and neck region, is exceedingly uncommon. In pediatric patients, such presentations may closely mimic congenital cystic lesions, leading to potential delays in diagnosis and management.

CASE PRESENTATION: We present the case of a 4-year-old male from the pastoralist Karamoja region of Northeastern Uganda who presented with a painless, slow-growing midline cystic neck mass of unspecified duration. The mass was mobile, located in the subcutaneous plane superficial to the strap muscles, and lacked communication with the deeper neck structures or oral cavity. Initially presumed to be a thyroglossal duct cyst, the lesion was managed via total surgical excision through a transverse neck incision. Histopathological examination revealed a thin-walled cyst containing multiple protoscolices with characteristic hooklets, consistent with a coenurus cyst caused by Multiceps multiceps. The patient's postoperative recovery was uneventful.

CONCLUSION: This case, the first of its kind reported in Uganda, demonstrates that Multiceps multiceps can clinically mimic a thyroglossal duct cyst. It underscores the necessity of histopathologic evaluation for all pediatric neck masses in endemic regions. Definitive management requires a high index of suspicion for multi-organ involvement, necessitating postoperative systemic anthelmintics and screening for occult central nervous system or ocular disease to ensure comprehensive care.