The forgotten lacrimal gland and lacrimal drainage apparatus: Pictorial review of CT and MRI imaging findings and differential diagnosis.

Abstract

The lacrimal gland is a bilobed serous gland located in the superolateral aspect of the orbit. Lacrimal system pathologies can be broadly divided into pathologies of the lacrimal gland and those of the lacrimal drainage system. These include distinct congenital, infectious, inflammatory, and benign, indeterminate, and malignant neoplastic lesions. Trauma and resultant fractures affecting lacrimal drainage apparatus is not part of this review; only non-traumatic diseases will be discussed. CT is the initial modality of choice because of its ability to delineate lacrimal system anatomy and demonstrate most lacrimal drainage system abnormalities and their extent. It also assesses bony architecture and characterizes the osseous changes. MRI is helpful in further characterizing these lesions and better assessing involvement of the surrounding soft tissue structures. In this pictorial review, we hope to revisit the anatomy of the lacrimal system, describe CT/MRI findings of the common/uncommon lacrimal system abnormalities and discuss relevance of imaging with regards to patient management.