Macrocystic lymphatic malformation with an unusual late presentation in a seven-year-old child: a case report and literature review.

Lymphatic malformations are rare congenital lesions usually presenting at birth or early childhood, with delayed cases in school-age children being uncommon. We report a 7-year-old girl with a 9-month, painless, enlarging left neck mass without infection or trauma. Exam showed a soft, compressible mass in the posterior cervical triangle. Magnetic resonance imaging revealed a multiloculated cystic lesion consistent with a macrocystic lymphatic malformation. Surgical excision confirmed lymphangioma, and the recovery was smooth. This case underlines the rare delayed presentation of a congenital lesion and the importance of including lymphatic malformations in pediatric neck mass diagnosis, regardless of age, highlighting imaging, and surgery's role in good outcomes.