Congenital Megacaruncle: A Unique and Innocent Ocular Adnexal Anomaly

Normal caruncular tissue contains a goblet cell–rich nonkeratinizing squamous epithelium, pilosebaceous units, eccrine and/or apocrine sweat glands, acini of lacrimal gland tissue, lobules of fat, and striated orbicularis muscle.¹ Acquired lesions of the caruncle have been well categorized.² The rarest lesions are congenital, including ectopias, dysgeneses (dysplasias), and duplications (supernumerary caruncles).^1,3,4 We report a case of a congenitally well-formed massive caruncle that we have designated as a “megacaruncle.”

A 55-year-old man had a lesion near the medial commissure of his right eye noted since birth (Figure 1A). It had never displayed a growth spurt. He had no ocular discomfort, visual decline, epiphora, or diplopia. Findings on a review of systems were negative. The lesion was firm, reddish, nontender, and attached to the right lower eyelid margin, which did not have a punctum. Visual acuity was 20/20 OU and the fundus was normal. The lesion was excised for cosmetic reasons.

The excised formalin-fixed tissue was white and firm and measured 7 × 4 × 3 mm. It was a symmetrically dome-shaped structure on both its external and cut fibrous surfaces. Histopathologically, it was covered by a goblet cell–rich nonkeratinizing squamous epithelium with a mild subepithelial infiltrate of chronic inflammatory cells (Figure 1B). There was a transition to keratinizing epidermis on its inferior aspect (Figure 1C). Cytokeratin 7 was found in the conjunctival epithelium but not the epidermis (Figure 1D). Epithelial tubular invaginations with goblet cells extended into the stroma, suggesting pseudoglands of Henle (Figure 1E and F and Figure 2A and B). Scattered lanugo hairs with their associated sebaceous glands were enveloped by thickly textured collagen fibers in the deep connective tissue (Figure 2C and D). The superficial stroma had the delicate collagen fibers of a substantia propria (Figure 2E). In the depths of the lesion were small lobules of adipose tissue and a few striated fibers of orbicularis muscle (Figure 2F). Eccrine, apocrine, and lacrimal gland tissues were not observed.

Under the jurisdiction of Massachusetts Eye and Ear Infirmary’s institutional review board, this study was considered exempt from institutional review board review. Informed consent was waived.

The current lesion displayed many attributes of a normal caruncle except for its disproportionately large size and lack of sweat and lacrimal glands. Only 1 previous case seems to be related and was reported as an ectopic caruncle.³ This “ectopia,” however, was continuous with the normal caruncle³ and thus was most likely the placoid extension of one large caruncle.

Dysplastic caruncles, which can be bilobed (encanthoschisis), are usually small nubbins of tissue that are in situ or displaced onto the medial aspect of the inferior palpebral conjunctiva. Bilaterally dysplastic caruncles can be a stigma of Goldenhar syndrome.⁴ By contrast, supernumerary caruncles are always unilateral and unassociated with other ocular abnormalities or Goldenhar syndrome. In such cases, there is a normally formed caruncle in its usual anatomical locale and a second or, exceptionally, third structure located in the medial palpebral conjunctiva. To our knowledge, a supernumerary caruncle has never been encountered in the superior palpebral conjunctiva. The predilection for lower medial palpebral conjunctiva probably stems from the embryologic origin of the normal caruncle from this topographic site.^4,5

The major differential diagnostic consideration is a solid caruncular dermoid, which is also present at birth. There is only 1 persuasive caruncular dermoid in the ophthalmic literature,⁶ and it adhered to the superomedial eyelid margin (where colobomas may also occur with dermoids^7,8). In contrast, abnormal caruncular lesions always involve the lower eyelid. The caruncular dermoid was distinguishable from remnants of the normal caruncle; our patient’s megacaruncle completely occupied the locus destined for a normal caruncle. Microscopically, the caruncular dermoid possessed a keratinizing epidermis-like surface and dense, thick collagen in place of a substantia propria.⁶ In contrast, the present lesion exhibited a goblet cell–rich nonkeratinizing squamous epithelium with pseudoglands of Henle and subepithelial, thin collagen strands typical of the caruncular substantia propria.

Corresponding Author: Frederick A. Jakobiec, MD, DSc, David G. Cogan Laboratory of Ophthalmic Pathology, Massachusetts Eye and Ear Infirmary, 243 Charles St, Ste 328, Boston, MA 02114 (fred_jakobiec@meei.harvard.edu).

Published Online: October 10, 2013. doi:10.1001/jamaophthalmol.2013.4401.

Author Contributions: Dr Jakobiec had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study concept and design: Bever, Jakobiec.

Acquisition of data: All authors.

Analysis and interpretation of data: Bever, Jakobiec, Mendoza.

Drafting of the manuscript: Bever, Jakobiec.

Critical revision of the manuscript for important intellectual content: All authors.

Administrative, technical, or material support: Jakobiec, Mendoza.

Study supervision: Jakobiec.

Conflict of Interest Disclosures: None reported.