Teaching Case

A 5-week-old child was referred to our Clinic for MRI imaging because of a cystic lesion in the lower nasal cavity on the right (inferior conchae, inferior meatus), clinically described as soft cystic formation, no choanal atresia; no other pathology during the clinical inspection. It was referred to our neuroradiological clinic to perform an MRI examination to clarify the lesion with differentials such as hemangioma or cystic tumour of any other origin.

In sedation, we performed a cerebral/nasopharyngeal MRI consisting of T2 blade sequences in sagittal, coronal, and axial view, followed by diffusion-weighted imaging, FLAIR, and T1 pre and post-contrast.

The nasolacrimal duct on the right side on MRI was dilated compared to the left. The complete duct could be evaluated and compared to the left side, which served as control. No surrounding soft tissue mass was observed, no contrast enhancement of suspect soft tissue. The complete nasolacrimal duct could be followed so atresia could be ruled out.

Congenital nasal obstruction remains an important clinical issue because neonates are obligate nasal breathers [1]. To find the pathology below the nasal obstruction is therefore of great interest, especially in choosing the right treatment.

When soft tissue mass/tumour is ruled out, the nasolacrimal duct remained dilated, leading to two major differential diagnoses, nasolacrimal duct obstruction as Dacryocystocele which is defined as obstruction of both ends of the nasolacrimal duct or an imperforate Hasner valve/membrane leading to dilation of the nasolacrimal duct [2].

Other possible differential diagnoses include nasal encephalocele, hemangioma, ethmoid mucocele, orbital dermoid cyst, or nasal glioma [3, 4]. These were ruled out because no soft tissue mass was seen as well as the nasolacrimal duct showed no obstruction or pathologic connection to the surrounding soft tissue or bone.

Conservative treatment followed for 2 weeks of nasolacrimal duct massage led to a re-opening of the nasolacrimal duct. Other therapy options remain surgical procedures such as lacrimal duct probing (Bowman probe) or surgical reconstruction procedures.