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Findings: Serial axial images through the orbit without contrast demonstrate bilateral masses involving the lacrimal glands and extending both superiorly and laterally to the globe into the anterior aspect of the orbit. Bilateral proptosis is noted.

Diagnosis: Bilateral lacrimal gland enlargement.

Discussion: Lacrimal enlargement can be divided into two presentations for the sake of discussion — unilateral and bilateral enlargement.

Unilateral enlargement – Tumors make up about half of all the masses seen in lacrimal glands. Benign pleomorphic adenomas and mixed tumors are common, the salivary gland being histologically the same as salivary glands. Malignant tumors are either primary or metastatic. Dacryoadenitis and pseudotumor are both inflammatory causes of lacrimal enlargement. Chronic dacryoadenitis sometimes has a rim enhancement on CT which differentiates it from the rest of the causes. Dermoid cysts are the only cause of lacrimal enlargement that can be definitely differentiated by CT. It appears as a well defined, oval, walled structure with a cystic interior that has low absorption, often as low as fat. A fluid level may also be seen.

Bilateral enlargement – The causes for bilateral enlargement of the lacrimals are most often systemic disorders, though any cause of unilateral enlargement can also cause bilateral enlargement of the lacrimals. The causes are sarcoidosis, Mikulicz’s syndrome, Sjögren syndrome, Graves disease, myxedema, amyloidosis, blood dyscrasias, pseudotumor and lymphoid hyperplasia.

Except for dermoid cysts, a diagnosis can not be made based on imaging alone. In this patient, a CT guided biopsy was done. The cytology report stated that there was a proliferation of lymphoid cells and macrophages, which brings us to a differential diagnosis of benign lymphoid proliferation versus lymphoma. The differentiation between these two, in the absence of other lesions of lymphoma, can be made only by special tumor marker or immunofluorescence studies.

References:
William E Rothfus in Computed Tomography of the Head,
Neck and Spine by Latchaw RE, p401-402, 1985.

Shields CL, Shields JA. "Lacrimal gland tumors"; International
Ophthalmology Clinics, 33(3):181-8, 1993.

Warner MA et al. "Benign and malignant tumors of the orbital cavity
including the lacrimal gland". Neuroimaging clinics of North America,
6(1):123-42, 1996.

Roy M et al. "Fine needle aspiration cytology of ophthalmic lesions".
Journal of the Indian Medical Association, 94(1):14-6, 1996.

Lemke AJ et al. "Differentiation of lacrimal gland tumors with high
resolution computerized tomography in comparison with magnetic resonance
tomography". Ophthalmologe, 93(3):284-91, 1996.

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