Ethmoid sinus disease: CT evaluation in 400 cases. Part I. Nonsurgical patients.

The unique anatomy of the ethmoid sinuses makes it difficult to interpret "soft-tissue clouding," especially on plain films. The clinical significance of isolated or generalized soft-tissue disease within ethmoid cells is unclear, and the patterns of bone erosion or remodeling must be relied on in establishing a specific differential diagnosis. Of 400 patients studied, 186 had inflammatory disease and 214 had tumors. Squamous cell carcinomas, metastases, and a few aggressive sarcomas were found almost exclusively to have bone destruction, while 94% of the remaining neoplasms were characterized by cavity remodeling. Further differentiation was sometimes possible because of the pattern and degree of tumor enhancement. Of the neoplasms, only the minor salivary gland lesions and neuromas had nonhomogeneous enhancement. Malignant lesions cannot be diagnosed with computed tomography (CT) unless bone destruction is present. Similarly, although the significance of persistent, benign-appearing soft-tissue disease during chemotherapy is unclear, tumor must always be suspected, even after many months of a stable CT appearance.