Lacrimal gland cyst

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Dacryops, also known as lacrimal gland or duct cyst, is a rare phenomenon where a retention cyst is formed within the lacrimal gland due to duct obstruction.

Epidemiology

Dacryops is an uncommon benign orbital lesion with an incidence of 0.5-2% . It usually affects young adults or middle-aged individuals.

Clinical presentation

It presents as a painless swelling in the superolateral aspect of the orbit. However, ectopic gland duct cysts have also been observed. They are usually unilateral although can be bilateral if due to a systemic cause such as Sjogren syndrome, Mikulicz syndrome, sarcoidosis, or lymphoproliferative disorders .

On examination appears as bluish-grey appearing cystic structure in superolateral aspect of eye .

Pathology

It is can be due to primary or secondary causes, although the pathophysiology is unclear.

One school of thought is that primary duct obstruction occurs as a result of congenital anomaly of the excretory duct or secondarily due to periductal inflammation or trauma resulting in hypersecretion and damage to ductule walls .

However, experiments performed in the last hundred years demonstrate that the occlusion of the lacrimal system does not result in the formation of dacryops, rather there is atrophy considering the fact that the physiological pressure is low in the lacrimal system . Thus, it has been hypothesized that a different mechanism is at work, and increased levels of secretory IgA have been recorded in the fluid within these cysts, which results in osmotic retention of fluid and expansion of the cyst .

Classification

Dacryops can be classified based on its location :

  • palpebral lobe cysts: simple dacryops is the most common
  • orbital lobe cysts
  • cysts of accessory lacrimal glands of Krause and Wolfring
  • cysts of ectopic (choristomatous) lacrimal glands

Radiographic features 

Ultrasound
  • cystic hypoechoic lesion with hyperechoic cyst wall
CT

Fluid density cyst, superficial in the palpebral type and deep within the orbit in the orbital type. There is no thick or nodular enhancement, and no associated bony erosion or destruction . Hyperdensity can occur if complicated by hemorrhage .                       

MRI
  • fluid intensity cyst with no post-contrast enhancement
Nuclear Medicine
  • Tc-99m pertechnetate scintigraphy: marked uptake

Treatment and prognosis

Surgical excision or marsupialization in patients with symptoms or poor cosmesis . Argon laser photocoagulation has also been described . Recurrence of the lesion after excision can occur as a result of incomplete removal .

Complications
  • infection
  • hemorrhage into the cyst
  • rupture

Differential diagnosis