Pneumosinus dilatans of the maxillary sinus. Case report.

A case of the rare condition pneumosinus dilatans of the maxillary sinus is presented. This is a rare differential diagnosis of a maxillary disease. The diagnostic imaging features of this condition are described, and a recommendation of views for adequately delineating this disorder is given. Only a few cases of pneumosinus dilatans of the maxillary sinus are described in the English-language literature, and the precise cause and pathogenesis remain obscure. We performed an enlargement of the maxillary ostium in order to increase the ventilation of the paranasal sinus. In the short-term follow-up, this patient has been asymptomatic. The postulated mechanism of air trapping in the sinus cavity seems to be logical in this case, because the symptoms were eliminated by surgically decompressing the sinus to overcome this valve mechanism.