Dacryops of Krause Gland in the Inferior Fornix in a Child

Dacryops of the accessory lacrimal glands are extremely rare, with only 4 previous cases reported to involve Krause glands in the last 60 years.^1-4 Dacryops of Krause glands have not been reported in the inferior fornix. The cause is often unclear, although numerous causes of secondary dacryops are known.^1-4

An otherwise healthy 2-year-old girl had a left lower eyelid mass, noted since age 2 months but enlarging during the previous 6 months. Her ocular and medical histories were unremarkable. Examination revealed a soft, fluctuant mass involving the left lower eyelid (Figure 1A). Computed tomography showed a cystic mass within the left lower eyelid, causing enophthalmos of the left globe (Figure 1B). Surgical dissection revealed a mass within the left inferior fornix, not involving the inferior tarsus. The lesion was excised intact.

Histopathologic examination revealed a cystic structure lined mostly by a double layer of cuboidal epithelium, with focal apical microvillus processes (Figure 2A). The underlying stroma focally contained small islands of normal-appearing lacrimal gland with mild chronic nongranulomatous inflammation (Figure 2B). The diagnosis was dacryops of an accessory lacrimal gland of Krause of the inferior fornix based on its location and the histopathologic findings.

The term dacryops was proposed by Schmidt in 1803 and refers to lacrimal ductal cysts of the primary or accessory lacrimal glands.⁴ Dacryops of the accessory lacrimal glands have been reported only rarely.^1-4 The apical microvillus processes^4,5 of these lesions and the nearby presence of glandular acini^1,3 are consistent with this diagnosis. Although histologically indistinguishable, Krause glands are anatomically located within the superior and inferior fornices, while Wolfring glands are found adherent or adjacent to the upper and lower tarsal plates.^4,5 Wolfring gland dacryops have been reported more frequently than Krause gland dacryops.^1-5 Weatherhead⁴ noted this disparity in 13 cases of Wolfring gland dacryops diagnosed during a 7-year period but only 1 case of Krause gland dacryops identified in the same period. All previously reported cases of Krause gland dacryops have occurred in the upper eyelids, where Krause glands are more abundant.^1-4

Although originally considered secondary to ductal outlet obstruction, the pathophysiology of dacryops recently has been proposed as a complex process involving periductal inflammation and subsequent passive dilation through a combination of hypersecretion, ductule wall weakening, and impaired neuromuscular contractility.^1,2,4-6 However, the chronic nongranulomatous inflammation, as observed in our case, also may occur secondary to the dacryops. High concentrations of IgA also have been identified in the cystic fluid, and it is postulated that ductal inflammation leads to increased IgA secretion with the resulting osmotic gradient contributing to cyst formation.⁴

Numerous secondary causes of dacryops have been described, including trachoma, pemphigoid, trauma, and periocular surgery, while infrequently, as in our case, the etiology remains unknown.^1-5 Secondary cases are seen mostly in older children and young adults; idiopathic cases, as in our case, are rarely reported but are thought to occur secondary to a congenital anomaly of the duct or an intrinsic abnormality in the secreted products, possibly related to chronic inflammation.^1-6 The treatment of dacryops, whether originating from the primary or accessory lacrimal glands, is complete excision of the cyst, ideally intact. Incomplete excision and intraoperative cyst rupture are associated with increased rates of recurrence and fistula formation.^4-6

In summary, we report dacryops of an inferior fornix accessory lacrimal gland of Krause. To our knowledge, this is the first reported case of Krause gland dacryops involving the lower eyelid. It remains imperative that all suspicious lesions are examined histopathologically and that the ophthalmologist considers the possibility of a lacrimal ductal cyst, even within the inferior fornix.

Correspondence: Dr Brownstein, Department of Ophthalmology, University of Ottawa Eye Institute, 501 Smyth Rd, Room W6213, Ottawa, ON K1H 8L6, Canada (sbrownstein@ohri.ca).