The forgotten lacrimal gland and lacrimal drainage apparatus: pictorial review of CT and MRI 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 nasolacrimal drainage apparatus. 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 any 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 will review the anatomy of the lacrimal system, describe CT/MRI findings of the common and uncommon lacrimal system abnormalities and discuss relevance of imaging with regards to patient management.

Figure 1.

Illustration showcasing the lacrimal drainage system and its key structures including the upper and lower puncti, canaliculi, lacrimal sac, and nasolacrimal duct.

Figure 2.

(a–f) Post-contrast CT (a–b) and MRI (c–f) in a 36-year-old female with dacryoadenitis. Diffuse enlargement of the right lacrimal gland (arrowheads) with homogeneous post-contrast enhancement (dotted arrow) and inflammatory fat stranding (arrows) extending into the soft tissues of the upper eyelid.

Figure 3.

(a–d) Post-contrast CT in a 65-year-old female: Bilateral asymmetric enlargement of the lacrimal glands (dotted arrows) associated with internal calcifications (arrows) caused by amyloidosis.

Figure 4.

(a–c) Post-contrast CT in 31-year-old female with dermoid cyst. Hypodense round lesion (arrowhead) with subtle peripheral enhancement (dotted arrow), exerting mass effect over the lateral aspect of the left globe and abutting the left lacrimal gland (arrow) with pressure erosion (asterisk) of the adjacent orbital osseous structures.

Figure 5.

(a, b) Post-contrast CT in a 64-year-old female with pleomorphic adenoma (biopsy proven). Enhancing soft tissue mass lesion (arrows) in the superolateral aspect of the left orbit arising from the lacrimal gland.

Figure 6.

(a–c) MRI in a 29-month-old with plexiform neurofibroma. Fusiform mass lesion (arrows) extending into the right orbit along the lateral wall, involving the right lateral rectus muscle, superior, and oblique muscles as well as the lacrimal gland.

Figure 7.

(a–c) Post-contrast CT in a 53-year-old female with adenoid cystic carcinoma of the lacrimal gland. Large locally invasive (arrowhead) solid partially calcified (dotted arrow) enhancing (arrow) lacrimal gland lesion associated with bone destruction (asterisk).

Figure 8.

(a, b) Post-contrast CT in an 18-day-old infant with dacryocystocele: Rounded, well-defined, rim-enhancing lesion (dotted arrow) abutting the medial preseptal right orbit, extending down the lacrimal canal into the inferior meatus (arrow), and obstructing the nasal cavity.

Figure 9.

(a, b) Post-contrast CT in an 18-year-old male with dacryocystitis. Soft tissue swelling (arrowhead) centered over the medial canthus of the left orbit associated with preseptal fat stranding (dotted arrow) and inflammatory changes in the left nasolacrimal duct (arrow), in keeping with dacryocystitis and preseptal cellulitis. (c, d, e) Post-contrast axial and coronal CT in a 47-year-old female with left preseptal (arrowhead) and post septal extraconal cellulitis (dotted arrow) and dacryocystitis (arrow).

Figure 10.

(a–e) MRI in a 37-year-old female with sclerosing orbital pseudotumour. Homogenously enhancing (arrowhead) soft tissue mass lesion in the medial canthus of the right orbit with expansion of the nasolacrimal duct. The mass extends into the nasal cavity, obliterating the right osteomeatal complex (dotted arrow) and into the intraconal orbital compartment (arrow), with thickening of the medial and inferior rectus muscles.

Figure 11.

(a–c) MRI in a 26-year-old female with granulomatosis with polyangitis. Soft tissue thickening of the left medial canthus (arrows) with extensive changes in the nasal cavity and paranasal sinuses, including septal perforation (dotted arrow), provide clues to the diagnosis.

Figure 12.

(a–f) MRI of the orbit in a 54-year-old male with capillary hemangioma. Avidly enhancing (arrowhead) large right orbital mass (dotted arrow) lesion involving the extraconal orbital compartment as well as the lacrimal sac and lacrimal duct (arrow).

Figure 13.

(a–e) CT (a) and MR (b–e) in a 68-year-old male with orbital lymphoma. Well-defined homogenously enhancing (arrowheads) soft tissue mass with low signal on T ₂W images (dotted arrows) and restricted diffusion on DWI (arrow) in the left medial canthus.

Figure 14.

(a–c) Post-contrast CT in a 75-year-old male with squamous cell carcinoma of the lacrimal sac. Heterogeneously enhancing soft tissue (arrowhead) along the medial wall of the left orbit with destruction of the lamina papyracea (arrow), widening of the nasolacrimal duct (dotted arrow), and infiltration of the left globe along the insertion of superior oblique and medial rectus muscles.