PART TWO
Diagnostic Cytology
Fig. 17.1 Divided system vitrectomy instrumentation.
fibrovascular tissue, and preretinal and epiretinal membranes
commonly seen as severe complications of diabetes mellitus.23
Vitrectomy is also used to remove intraocular hemorrhage caused
by trauma, sickle cell disease, and branch retinal vein occlu-
sion24 and to remove intraocular foreign bodies. Endophthalmi-
tis is an ocular emergency, but a recent review indicated 53% of
patients may attain better than 20/40 vision after treatment with
immediate intravitreal antibiotics and vitrectomy.25,26
In addition to these therapeutic indications, vitrectomy has
been performed for diagnostic purposes. Various authors have
reviewed numerous cases in which diagnostic vitrectomies were
performed.27-29 One group has divided diagnostic vitrectomies
into three categories:
(1) Those performed to make specific diagnoses;
(2) Those performed to confirm a presumed but
clinically unproven diagnosis; and
(3) Those performed to diagnose a previously
unsuspected condition.
The cases reviewed included postoperative endophthalmitis,
neoplastic lesions (e.g. ocular lymphoma, malignant melanoma,
metastatic tumors, and histiocytic lymphomas). In another
review of the cytologic findings of 74 vitreous specimens from
60 patients with diagnoses such as large-cell lymphomas, plas-
macytoma, hemorrhage, sarcoidosis, and identifiable infectious
agents, including parasites, bacteria, and fungi, it was concluded
that vitrectomies could be divided into three broad diagnostic
categories: inflammation/infection (54 specimens/41 patients),
hemorrhage
(12
specimens/12
patients),
and
malignancy
(8 specimens/7 patients).30 Furthermore, some reports have
described the use of diagnostic vitrectomies in confirming breast
carcinoma metastatic to the eye, with the cytologic findings in
the vitreous cells resembling the primary breast carcinoma.31,32
The most likely lesions encountered in routine practice are
illustrated in Table 17.1.
Several methods of processing intraocular fluids have been
described in the literature, including the membrane filter tech-
nique, the cytocentrifugation technique, and the celloidin-bag
technique.33-36 The method to be described was developed
by one of us (DBM) for processing the vitrectomy specimens
received by the UCLA Cytology Service.13
Table 17.1 Cellular Components Found in Vitrectomy Specimens at
UCLA 1991-2006
Cellular components or diagnosis
Number
Neuroepithelial fragments
including spindle cell membrane
1314
Retinal detachment
14
Acute retinal necrosis
1
CMV retinitis
5
Hemorrhage
1211
Inflammation
667
Acute endophthalmitis
48
Bacterial
5
Fungal
4
Cataract
498
Lens fragment
284
Fibrovascular tissue
268
Epithelium
94
Conjunctival, ciliary body epithelium
37
Uveal fragments
36
RPE
38
Lymphoma
16
Malignant lymphoma
13
T-cell lymphoma
1
B-cell lymphoma
1
Amyloidosis
3
Asteroid hyalosis
13
Acellular including silicone oil and
371
perfluorocarbon removal
Method
Intraocular specimens processed by the UCLA Cytology Service
are collected in sterile cassettes and delivered by messenger to
the cytology laboratory. If there is any delay, the specimens are
refrigerated.
Appearance and volume of the specimen are described. The
entire specimen is centrifuged for 5 minutes at 3200 rpm. The
supernatant is carefully pipetted off, and the gross appearance of
the sediment is evaluated. If the sediment is bloody or appears
to be composed of lens fragments, care must be taken in approx-
imating the amount of material needed to prepare a monolayer
cytospin slide preparation.
Cytocentrifuge Preparation
The cytospin chambers are prepared according to the manufac-
turer's instructions.35 If sediment is scant, four cytospin slides
are prepared. If an adequate amount of material is left in the
centrifuge tube, about 0.5 mL or more, a cell block is made (see
subsequent discussion).
One drop
of 22% bovine albumin is
added to
each
cytospin chamber before the addition of the specimen. The
specimen is cytocentrifuged at 1000 rpm for 5 minutes. After
cytocentrifugation, slides are fixed in 95% ethyl alcohol or air-
dried for May Grunwald Giemsa (MGG) stain as directed by the
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