We report a rare case of bilateral maxillary mucoceles. This was the primary presentation in a child with an underlying diagnosis of cystic fibrosis.

A five-month-old infant presented with isolated symptoms of nasal congestion. Initial examination and investigation with computed tomography identified the cause to be bilateral maxillary mucoceles. The child was investigated for cystic fibrosis and found to be positive. Given the young age and anatomy, a modified surgical approach was used to treat the mucoceles, comprising endoscopic and bilateral uncapping of the maxillary mucocele, uncinectomy, and middle meatal antrostomy. The child was then followed up with appropriate treatment for cystic fibrosis. At six-week follow up, there was no recurrence of symptoms.

Maxillary mucoceles are extremely rare but can present in patients with chronic sinusitis or cystic fibrosis. To our knowledge, there are no prior reports of this condition being the primary indicator of underlying cystic fibrosis in the absence of upper respiratory tract symptoms. Doctors should be aware that mucoceles can present in very young individuals and may indicate an underlying diagnosis of cystic fibrosis. A high index of clinical suspicion will avoid delays in diagnosis and long-term management.