Based on a review of the literature and analysis of six new cases, three categories of enlarged, aerated sinuses are defined, namely: hypersinus, pneumosinus dilatans, and pneumocele. The information gained by our study of the area variation of the frontal sinuses in a normal population (part I of this paper) was utilized to define the term hypersinus. In this condition there is generalized enlargement of the sinus beyond the upper limit of normal in an asymptomatic patient. The principal difference between pneumosinus dilatans and a pneumocele is the presence of bony thinning or erosion in the latter entity. The clinical findings and the possible etiologies of these conditions are discussed.

Malignant tumors of the paranasal sinuses are often found to be greatly advanced by the time a clinical or radiologic diagnosis is established. Therefore, the overall cure rate is low, even when surgery and radiation therapy are combined. The clinical manifestations and pathologic findings are analyzed in 200 cases to illustrate the wide spectrum of these tumors as to their type, specific location, and the extent to which they can spread within the sinuses and to adjacent anatomic areas. The various radiologic modalities, including conventional x-ray films, angiography, and conventional and computed tomography are presented. Their relative merit in the diagnosis and staging of these tumors is evaluated.

Computed tomography is routinely used in the evaluation of patients suspected to have deep neck infections. This 10-year retrospective study compares preoperative computed tomography scan reports with intraoperative findings in 38 patients who underwent surgical exploration of the parapharyngeal or retropharyngeal space within 48 hours of their radiographic assessment. Overall, intraoperative findings confirmed computed tomography scan interpretation in 76.3% of the patients. The false-positive rate was 13.2%, and the false-negative rate was 10.5%. The sensitivity of computed tomography scan for detection of parapharyngeal space or retropharyngeal space abscess was 87.9%. This study's documentation of false-positive computed tomography scans in the evaluation of deep neck infections emphasizes the importance of correlating radiologic interpretation with clinical examination before surgical intervention.