Sampling of iris tumours

Sampling techniques

• Broad iridectomy

• FNA

• Small gauge vitrector

• Kelly Descemet’s membrane

• Punch bx

Technically difficult

Requiring corneal sutures

£

FNA experience

• Hoovering a layer of cells from the surface with a bevelled needle

• 50% equivocal diagnosis-Why?

1. Low cellularity

2. Sampling of Vitamin C modified cells when in contact with aqueous and not deeper cells

Mudhar HS, Saunders E, Rundle P, Rennie IG, Sisley K.Br J Ophthalmol. 2009 Apr;93(4):535-40

New method: TC FCA • A clear corneal paracentesis (opposite the iris lesion

being biopsied.

• Viscoelastic introduced into the AC

• A 25-guage Rycroft, or Viscoflow cannula attached to a 2 millilitre syringe and introduced in to the AC.

• Negative pressure within the dry syringe, the cannula bevel passed repeatedly into the substance of the iris tumour.

• This had the effect of creating what looked like a ‘phaco groove’ within the iris lesion

Method

• The cannula and syringe transferred into a tube containing an alcohol based cytology fixative.

• Repeated flushing of the Rycroft cannula to ensure all lesional tissue was transferred into the fixative

• No corneal sutures required.

Up to 1.5mm long

Complications:

• Minor post bx haemorrhage day 1 post-bx.

Diagnostic outcomes

• 10 MMs

• 1 metastatic lung adenoca

• 1 pigmented adenoma

Advantage:

Cheap

Quick

Minimal complication

No cornea sutures

Samples deeper melanoma cells (unmodified by aqueous Vitamin C) allowing unequivocal diagnosis in MM cases.

No ‘inadequate’ samples so far.

Sampling vitreous cells.

Anecdotal observation

• VR surgeons had noticed quite often that cells in the vitreous tended to concentrate in the cortical vitreous and less in core vitreous.

WHY?

• Cortical vitreous has different physicochemical properties to core vitreous….cells being trapped.

• Cells near a source of oxygen (retina) and therefore likely to survive.

Literature

• Documented false negative rate with core vitreous biopsy……often several biopsies needed before a positive diagnosis is made (lymphoma).

Test the idea of differential distribution of cells.

• 5 patients

• All patients were consented routinely for a core vitreous bx, followed by a PPV (pars plana vitrectomy)

• Cytology-we received 2 specimens-Core bx and vitrectomy.

• Cytopsins prepared.

Results

• PPV specimen’s, 7.4 to 78 x cellular compared to core bx

Case number Core vitreous bx-screening

cytopsin cell count/ mm2

PPV specimen- screening

cytospin cell count /mm2

Core vitreous bx cell block final

diagnosis

PPV

cell block

final diagnosis

1 12 89 Granulomatous

inflammation

Granulomatous

vitritis-no infectious agent

detected.

2 1 18 Non-diagnostic-insufficient cells

Primary intraocular

Diffuse large B-cell lymphoma

(PIOL)

3 15 280 Inflammation (NOS)

Paraneoplastic granulomatous

vitritis and retinitis.

4 3 235 Non-diagnostic-insufficient cells

Granulomatous vitritis

-Sarcoid

5 1 33 Non-diagnostic-insufficient cells

Metastatic Diffuse large B-

cell lymphoma of testis

Experience to date with complications:

One case had peripheral retinal tear, with peripheral retinal fragments ending up in specimen. However, fortuitously, the fragments contained the diagnostic pathology (!).

Present practice:

• Any vitreous infiltrate suspicious for lymphoma undergoes formal PPV with submission of vitreous cassette or bag to ophthalmic histopathology service.

• Amount of tissue allows immuno and PCR for IgH, TCR, IL-6/IL-10 ratio etc.

Thank you.