Masses of the Lacrimal Fossa

Any tumor, regardless of its histology, can be located in the lacrimal fossa, but in this chapter, we focus on the ultrasound diagnosis of lesions of the lacrimal gland itself. The tumors of the lacrimal gland predominate in the deep lobe of the gland. Because the lacrimal gland is superficial, it is examined first with paraocular sections, but when the lesion is large, the deep (posterior) part must also be examined by transocular sections. Dacryops are cysts of the lacrimal gland, imaged only when bothersome. Color Doppler imaging has a key role in the diagnosis of tumors of the lacrimal gland because the resistive index (RI) guides the diagnostic perspective: a low RI, < 0.70, suggests a lymphoid lesion and indicates biopsy, whereas an RI > 0.70 suggests an epithelial tumor and indicates surgical excision, without effraction of the capsule. Epithelial tumors represent 11.5% of all primary orbital tumors. They include pleomorphic adenoma or benign mixed tumor, pleomorphic adenocarcinoma or malignant mixed tumor, and adenoid cystic carcinoma. But at the end of the chapter, lymphoid lesions are briefly examined along with other lesions such as solitary fibrous tumor, whose localization in the lacrimal fossa is not an anecdotal situation.