What are the consequences of a lesion located at the hiatus semilunaris in the middle meatus of the nasal cavity?

A lesion at the hiatus semilunaris can lead to obstruction of the ipsilateral maxillary sinus, anterior and middle ethmoid air cells, and frontal sinus, known as the ostiomeatal unit pattern of obstruction. Key diagnostic features include opacification and fluid levels in these sinuses on CT. Clinically, patients may present with symptoms of sinusitis such as facial pain and nasal congestion. A common pitfall is mistaking this for isolated sinusitis without recognizing the underlying structural cause.