Microscopy June 2019

Yesterday’s session had a variety of attendees, including Moorfields ophthalmologists, a medical student on elective, our regular veterinary pathologists Simon and Alejandro, and a visiting pathologist from Australia.

Simon brought a feline eye with a ciliary body adenoma. This is a rare entity in humans (and not to be confused with Fuchs’ adenoma which I’ve mentioned in a previous post here).

If you’re curious about tumours of the human ciliary body pigmented and non-pigmented epithelium, here are a few open access articles to get you started.

Ciliary body adenoma of non-pigmented epithelium by Mansoor and Qureshi 2004

Ciliary-body adenoma of the non-pigmented epithelium with rubeosis iridis treated with plaque brachytherapy and bevacizumab by Papstefanou and Cohen 2012

Adenocarcinoma of the pigmented ciliary epithelium by Sukeda et al 2014

Adenoma of the Nonpigmented Ciliary Body and Iris Epithelium in Mexican Mestizo Patients by Serna-Ojeda et al 2015

Here are a few of the human cases we discussed.

Case 1

Enucleation for choroidal melanoma

Low power

Low power view of the posterior choroid shows a markedly necrotic choroidal tumour with patchy melanin pigment. The retina is detached, and there is subretinal blood.

Higher power

Higher power view of viable tumour shows spindled cells with melanin pigment consistent with melanoma.

Higher power of sclera

This view shows necrotic tumour (on the left) with intact sclera. The extraocular soft tissue has pronounced fibroblastic activity, which I think secondary to the tumour necrosis.

Low power

And unrelated to the tumour, this is the optic disc and optic nerve. The section demonstrates the central retinal artery and vein at their entry/exit point to the eye.

Case 2

Temporal artery biopsy

Low power

Low power view shows a muscular artery with a narrowed lumen. The wall is thickened and inflamed: including in the vasa vasorum (adventitial blood vessels).

Higher power

Higher power shows an occasional multinucleate giant cell. These are not essential for the diagnosis.

This is temporal arteritis.

We had a chat about the clinical criteria of temporal (giant cell) arteritis as well as the timing of the biopsy. There seems to be a persistent belief that a temporal artery biopsy is only useful if done within a few days of starting corticosteroid treatment. This is not the case. Temporal artery biopsies may still show histological features of arteritis a month after steroid treatment has been started.

For comparison, there’s a picture of a normal temporal artery in one of my posts from last year.

Here are a couple of open access articles about steroids and temporal artery biopsies.

Effect of prior steroid treatment on temporal artery biopsy findings in giant cell arteritis from Ray-Chaudhuri et al 2002

UpToDate: Temporal artery biopsy technique by Shaw (updated 2018)

I think the take-home message is that although it’s desirable to take the biopsy sooner rather than later, do not delay steroid treatment because of timing issues around the biopsy.

Case 3

This is an evisceration from an eye with complex problems and multiple surgical procedures.

Low power

The low power view includes iris and ciliary body (towards the top) with two large empty spaces/cystic cavities and disorganised vitreous and retina towards the right. At the extreme right is some inflamed choroid.

Higher power of iris

Higher power view of the iris and ciliary body shows a sheet of multilayered epithelium on the anterior and posterior iris surfaces, and extending into the vitreous cavity…

Higher power of vitreous cavity

… and lining the cystic cavity noted on lower power.

The epithelium is similar to conjunctiva or cornea (in other fields, I would see goblet cells) and not something we should see inside the eye.

In addition to other pathology, this eye demonstrates extreme epithelial downgrowth. This can occur after trauma or surgery, when ocular surface epithelium gains access to the interior of the eye. It can obstruct the angle, causing secondary glaucoma, and it is extremely difficult to treat.

Here’s a large case series on epithelial downgrowth (it’s a PDF file rather than a web page):

Epithelial downgrowth: a 30-year clinicopathological review by Weiner et al 1989.

My next session will be on Wednesday 17 July – see you then!

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