Evaluation of CT Findings in Squamous and Non-Squamous Cell Carcinomas of the Maxillary Sinus

The aim of the present study was to compare CT images between squamous cell carcinoma (SCC) and non-SCC found in the maxillary sinus, and to identify features that could be used to differentiate between SCC and non-SCC. Patients who visited the Faculty of Dentistry, Okayama University Hospital, between April 2007 and March 2023, underwent head and neck CT, and had tumors extending into the maxillary sinus that were diagnosed histopathologically as malignancy, were enrolled. The main seat of the mass, bony changes in the maxillary sinus wall, and extension into the surrounding area were assessed. These imaging features were evaluated according to SCC or non-SCC, and the characteristics of the two classes were assessed. Comparisons between the two groups were made using the Fisher exact probability test. There were 11 cases each of SCC and non-SCC. In 11 SCC and 7 non-SCC cases, the main seat of the mass occupied the entire maxillary sinus. The frequency of mass occupying the whole sinus was significantly higher in SCC than in non-SCC (p<0.05). Bone-thickening type disease was found only in squamous cell carcinoma 4/11 (36.4%), with there being a significant difference between SCC and non-SCC (p<0.05). Occupancy of the entire maxillary sinus by the mass and bone thickening on CT images were useful for differentiating between SCC and non-SCC arising in the maxillary sinus.