Imaging of the Lacrimal Gland
Section snippets
Structure and Function of the Normal Lacrimal Gland
The lacrimal gland is a serous gland, bi-lobed in shape, and measuring approximately 20 × 12 × 5 mm. While somewhat variable in size between individuals, differences between the normally symmetrical right and left glands provide an important clue to the presence of pathology. The larger orbital lobe is situated posteriorly and superiorly within a shallow bony fossa indenting the inferior surface of the supraorbital margin of the frontal bone, while the smaller palpebral lobe is situated more
Imaging of the Lacrimal Gland
Ultrasound (US), CT, and MRI are all used in imaging of the lacrimal gland. As in most situations, imaging is invaluable in (i) confirming whether the lesion lies within the lacrimal gland or within any of the other orbital structures where it would be likely to present clinically in the same way; (ii) defining the nature and extent of the lesion for diagnosis and surgical planning; and (iii) monitoring progress over time and the effectiveness of treatment.
Tumors of the Lacrimal Gland
About 10% of space-occupying lesions of the orbit arise from within the lacrimal gland.8 Lacrimal neoplasms arise from all the structures related to the gland and its function, namely its aqueous (and also sebaceous) secretory epithelial tissue, its lymphoid tissue, and its nervous and vascular tissue. The full range of degrees of malignancy is also represented. Assessing the relative incidence of various lacrimal tumors and other lacrimal masses such as dacrocysts has been difficult. Table 1
Epithelial Tumors of the Lacrimal Gland
Primary tumors deriving from epithelial tissue are relatively common with recent reports suggesting that they account for approximately 20% of all solid lacrimal gland masses.8
Clinical presentation is typically with proptosis and inferior and medial displacement of the eye. More rapidly growing tumors are more likely to present with diplopia as there is less time for compensation. While malignant lesions may present with symptoms of pain, and the perineural involvement of adenoid cystic
Neural Tumors
Derived from the neural tissue of the lacrimal gland and neighboring structures, localized neurofibromas may occur within the lacrimal fossa. They can be difficult to differentiate on their radiological appearances from a pleomorphic adenoma since they are also well-circumscribed, usually homogenous masses that are isodense to extraocular muscle on CT and may likewise excavate the lacrimal fossa.31, 32 Lacrimal neurofibromas are associated with systemic neurofibromatosis in 12% of cases. They
Metastases
Metastases may rarely occur to the lacrimal gland and their imaging appearances are similar to those of primary tumors.33 Additionally, there may be lacrimal spread of metastatic tumor from neighboring orbital soft tissue or bony structures. Carcinoma of the breast most commonly metastasizes to the soft tissue, whereas prostatic carcinoma results in bony metastases. Melanoma may spread either to soft tissue or to bone. Renal and thyroid metastases produce osteolytic bony lesions. In children,
Other Tumors
Primary squamous cell carcinoma and sebaceous carcinoma may arise from the lacrimal gland, due to the presence of heterotopic tissue.8 More typically, such tumors may spread from the upper eyelid, or in the case of sebaceous carcinoma, from the meibomian glands of the tarsus or the sebaceous glands of the eyelashes and brow hairs. Their appearances are typical of malignant lacrimal tumors—a soft-tissue mass with bony erosion. Early radiological diagnosis of such lesions dramatically affects
Infection of the Lacrimal Gland
Like most epithelial structures in contact with the outside, acute infection (dacryoadenitis) may occur from bacterial or viral infection. The condition is normally unilateral and usually occurs in children and young adults. A smooth swelling will be seen on imaging and enlargement of other structures such as lymph nodes may be visualized.37 Care must be taken to determine any orbital, cavernous, or intracranial extension or associated venous sinus thrombosis. Chronic dacryoadenitis may result
Dermoid Cysts
Dermoid cysts are thought to arise from ectodermal rests, separated off at suture lines, and are therefore developmental choristomas. They may be superficial or deep and often have histological features of rupture (50%); less commonly this is manifested clinically with low-grade inflammatory features. On imaging, they are usually associated with adjacent bony change and localized excavation of bone. They may show calcification. Frontozygomatic dermoids may be difficult to differentiate from
Inflammatory and Granulomatous Pathology of the Lacrimal Gland
Inflammatory lacrimal disease is the second most common inflammatory disease of the orbit (after orbital myositis).16 Clinical presentation is characterized by pain and a tender palpable lacrimal gland. Approximately 50% of cases are associated with a systemic condition such as sarcoidosis, Sjogren’s syndrome, Wegener’s granulomatosis, or other autoimmune conditions.
Inflammatory conditions of the lacrimal gland are characterized radiologically by diffuse unilateral or bilateral enlargement with
Lacrimal Ductal Cysts (Dacrocysts or Dacryops)
Lacrimal ductal cysts develop mainly within the palpebral lobe of the gland where the tear ducts emerge on to the conjunctiva. They typically manifest as a slow-growing painless mass in the region of the external canthus that causes cosmetic problems. Sometimes they may result in a dry eye as many of the neighboring ducts become secondarily compressed. The pathogenesis is thought to relate to trauma or inflammation, weakening the ductal walls, allowing ductal dilatation. Their cystic nature is
Conclusions
The myriad of pathologies of the lacrimal gland, reflecting its site, function, and developmental link with the salivary glands, present particular diagnostic challenges for imaging. The mainstays of such imaging are CT and MRI. Due to the bony relations of the gland and the presence of calcification within some lesions, the latter complements rather than supersedes the former. As benign and malignant epithelial pathology may be indistinguishable on imaging, excision of the whole gland at the
References (56)
- et al.
Laboratory findings in tear fluid analysis
Clin Chim Acta
(2006) Colour Doppler imaging of the eye and orbit
Radiol Clin North Am
(1998)- et al.
Tumours arising in the palpebral lobe of the lacrimal gland
Ophthalmology
(1996) - et al.
Combined clinical and computed tomographic diagnosis of primary lacrimal fossa lesions
Ann J Ophthalmol
(1982) - et al.
Lacrimal gland and fossa lesions: an approach to diagnosis and management
Ophthalmology
(1979) - et al.
Primary ductal adenocarcinoma of the lacrimal gland
Ophthalmology
(1996) - et al.
Lymphoid hyperplasia and malignant lymphoma occurring in the ocular adnexa (orbit, conjunctiva, and eyelids): a prospective multiparametric analysis of 108 cases during 1977 to 1987
Hum Pathol
(1990) - et al.
Lymphoproliferative lesions of the lacrimal gland: clinicopathological, immunohistochemical and molecular genetic analysis
Can J Ophthalmol
(2005) - et al.
Clinical, morphologic, immunophenotypic, and molecular genetic analysis of bilateral ocular adnexal lymphoid neoplasms in 17 patients
Am J Ophthalmol
(1987) - et al.
Orbital and conjunctival lymphoma treatment and prognosis
Radiother Oncol
(1988)
Benign peripheral nerve sheath tumours (neurofibromatosis of the lacrimal gland)
Ophthalmology
Localized orbital neurofibromas
Am J Ophthalmol
Orbital metastasis: role of magnetic resonance imaging and computed tomography
Radiol Clin North Am
Orbital rhabdomyosarcoma—the radiological characteristics
Clin Radiol
Pseudotumor of the orbitClinical, pathologic, and radiologic evaluation
Radiol Clin North Am
Survey of 1264 patients with orbital tumors and simulating lesions: The 2002 Montgomery Lecture, part 1
Ophthalmology
Clinical and pathological characteristics of Mikulicz’s disease (IgG4-related plasmacytic exocrinopathy)
Autoimmunol Rev
Lacrimal gland and fossa lesions: role of computed tomography
Radiol Clin North Am
Nuclear imaging: 67gallium, 201thallium, 18F-labeled fluro-2-deoxy-D-glucose positron emission tomography
Clin Chest Med
Recent advances in pathology as applied to orbital biopsyPractical considerations
Ophthalmology
Rosai-Dorfman disease presenting as bilateral lacrimal gland enlargement
Am J Ophthalmol
Mucoepidermoid carcinoma of the lacrimal glandReport of a case with oncocytic features arising in a patient with chronic dacryops
Ophthalmology
Combined dacryops with underlying benign mixed cell tumor of the lacrimal gland
Am J Ophthalmol
Last’s Anatomy Regional and Applied
Surgical treatment of dry eye syndrome: conjunctival graft of the minor salivary gland
J Craniofac Surg
Surface coil MR evaluation of a lacrimal gland carcinoma
J Comput Assist Tomogr
Normal computed tomography and magnetic resonance imaging anatomy of the globe, orbit, and visual pathways
Neuroimaging Clin North Am
Recognition of distinctive patterns of gallium-67 distribution in sarcoidosis
J Nucl Med
Cited by (23)
Routine and Advanced Ultrasound of Major Salivary Glands
2018, Neuroimaging Clinics of North AmericaCitation Excerpt :The lacrimal glands are simultaneously involved in several diseases affecting the salivary glands, including Sjögren syndrome (SS), IgG4-related disease (RD), and mucosa-associated lymphoid tissue (MALT) lymphoma. The authors also assess lacrimal glands sonographically if these pathologies are suspected, by applying the transducer lightly to the superolateral quadrant of each orbit with the patient’s eyes closed.9 Lacrimal glands normally appear as smooth triangular homogenously echogenic structures, but if involved by the aforementioned diseases, they appear diffusely or partially hypoechoic and have variable size (Fig. 7).
Intraorbital Cystic Lesions: An Imaging Spectrum
2015, Current Problems in Diagnostic RadiologyCitation Excerpt :It is situated at the outer canthus of the eye if due to blockage of the main lacrimal gland, at the medial canthus if due to blockage of the nasolacrimal duct, and in the conjunctival fornices if ducts of accessory glands of Wolfring and Krause are blocked.17 The blockage may be congenital (in neonates),18 posttraumatic or infective in origin, or it may be caused owing to blockage by a slowly growing lacrimal tumor.19 Rarely, the epithelium of the cyst may itself transform into a squamous cell carcinoma.20
Head and Neck Radiology
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