Post on 17-Dec-2015
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.