Persistent eyelid lump
First, some background orientation. Here’s a normal full-thickness eyelid.
Epithelium forms a continuous cover of the surfaces, with epidermis at the top and conjunctiva at the bottom. Beneath the epidermis lies skeletal muscle (orbicularis). Deep to that lies the tarsal plate. The tarsal plate consists of dense fibroconnective tissue and the meibomian glands, which are sebaceous glands. The meibomian glands produce an oily secretion which forms part of the tear film.
In this annotated image, I’ve outlined a few of the meibomian gland’s sebaceous lobules in yellow.
On higher power, we see that the sebaceous lobules have a peripheral layer of rather small basaloid cells (blue). The remainder of the cells are larger with pale foamy cytoplasm: an indicator of lipid contents. There is a ductule towards the left. The conjunctival epithelium includes goblet cells.
In the annotated image, I’ve outlined a lobule in yellow, marked the basaloid cells with blue and cross-hatched the foamy cells in green. I’ve outlined the ductule in black and marked a few goblet cells with asterisks. Unlike a pilosebaceous unit within the skin, there are no hair follicles here.
And now for the actual case.
This common lesion typically presents as a persistent lump of the eyelid. It is usually painless, although it may sometimes be painful and/or inflamed. The ophthalmologist may curette (scrape/scoop out) the lump and send tissue in multiple pieces. Sometimes, particularly if a tumour is suspected, a full-thickness biopsy may be taken.
First of all, note that this isn’t a nicely orientated piece of full thickness eyelid. This is obliquely orientated tarsal plate (with dense collagen) and a partial covering of conjunctival epithelium towards the left. In the central part of the specimen are a few epithelial structures, but the meibomian gland lobules are essentially obliterated. What we have left are large empty spaces and a patchy cellular infilrate. Even at this low power, you can appreciate some multinucleate giant cells.
In the annotated image, I’ve indicated the empty spaces (e) and the giant cells (g)
Here’s a higher power image. There are plenty of rounded empty spaces. These will have contained fat (which dissolved out during laboratory processing). There are also several multinucleate giant cells. These have the jumbled nuclei typical of foreign body-type giant cells. In this case, they have formed as a reaction to fat/oil leaking from the meibomian glands.
In the annotated image, I’ve marked the empty spaces (e) and giant cells (g).
This appearance is typical of the humble chalazion, which is a very common eyelid condition. It frequently resolves without intervention, or sometimes it is managed surgically with curettage or a larger biopsy. A persistent or recurrent eyelid lump can raise the suspicion of sebaceous carcinoma (a clinical mimic), which is the main reason specimens are submitted for examination.
Here are a few open access articles about chalazion:
Chalazion by Jordan and Beier. This article provides a general overview.
Chalazion by Arbabi et al. This paper covers the presentation and management of chalazion in a primary care setting.
Differential Diagnosis of the Swollen Red Eyelid by Carlisle and Digiovanni. This article only mentions chalazion in passing, but it’s got some nice figures demonstrating anatomy of the orbit and eyelid, and practical clinical advice.
The importance of considering sebaceous gland carcinoma in presumed chalazia in South Asian patients? by Sagili and Malhotra. In this case report, the authors suggest that a low threshold of suspicion for sebaceous carcinoma is merited when assessing patients of South Asian origin.
Conservative therapy for chalazia: is it really effective? by Wu et al. Often, management of chalazion doesn’t give rise to surgical specimens!