Hidden in Plain Sight: Neglected Congenital Ranula Presenting as Failure to Thrive in an Infant.

Congenital ranula is a rare mucous extravasation cyst arising from the sublingual gland, presenting early in life and potentially causing feeding difficulties and growth failure. We report a two-month-old infant with a large intraoral swelling present since birth, leading to poor weight gain and tongue displacement. Ultrasound confirmed a plunging ranula, and marsupialization was successfully performed. Post-surgery, the infant showed significant improvement in feeding and growth. This case highlights the importance of early oral cavity examination in neonates, as timely identification and intervention can prevent complications and ensure improved nutritional and developmental outcomes in affected infants.