Pediatric Neck Swelling: A Case Report of Fourth Branchial Cleft Cyst.

Pediatric neck masses present a diagnostic challenge, encompassing various etiologies, including rare entities like branchial cleft anomalies. Branchial cleft cysts, resulting from incomplete embryonic cleft obliteration, may become symptomatic. This case report describes a seven-year-old boy who presented with a week-long history of fever and progressively enlarging left anterior cervical swelling. Physical examination revealed a fluctuant, non-tender mass, prompting diagnostic investigations. Laboratory results indicated an elevated white blood cell count and inflammatory markers. Computed tomography identified a hypodense, rim-enhancing mass consistent with an abscess secondary to a fourth branchial cleft cyst. Ultrasound-guided aspiration yielded purulent material, confirming infection. This case highlights the clinical significance of fourth branchial cleft cysts as rare inflammatory neck masses in pediatric patients. The embryological context informs their diverse anatomical manifestations. Surgical excision remains the primary treatment, demanding consideration of anatomical complexities.