Fig. 5.6 Immature cells showing irregular nuclear outlines in HSIL. Thinprep
(papanicolaou x Mp).
Fig. 5.8 pleomorphic cells and clean background in squamous cell
carcinoma. Surepath (papanicolaou x Hp).
Fig. 5.7 Syncytium of malignant cells in squamous cell carcinoma with
variation in nuclear size and shape, irregular chromatin distribution and
clinging diathesis. Thinprep (papanicolaou x hp).
Fig. 5.9 Normal endometrial cells in tight cluster and enhanced nuclear
detail. thinprep (papanicolaou x Mp).
The three major processing modalities for nongynecologic spec-
imens consist of
direct smear, filtration
(Millipore, SurePath, and
All three techniques share the capacity to archive a portion of
the specimen for the application of special and immunocyto-
chemical stains. Each modality subjects the cellular material
to different degrees of physical forces and chemical influences.
This will result in certain artifact profiles that can affect cytomor-
phologic interpretation. True tissue fragments with architectural
features similar to those of histologic specimens are present in
quality direct smears (Fig. 5.11). The use of
stains in conjunction with the direct smears technique
allows for on-site cellular adequacy of FNA. The importance of
on-site specimen evaluation cannot be overstated since it has
been shown conclusively to significantly reduce the inadequacy
rate.15 The preservation of diagnostically important true tissue
fragments and the three-dimensional microtopography of the
Millipore cellulose filter produces an increased depth of field
and subsequent exquisite cytologic detail (Fig. 5.12). The Thin-
Prep technique consistently produces the truest monolayer, thus
minimizing the obscuring effects of background elements and
cellular clumping (Fig. 5.13). SurePath and Cytospin prepara-
tions also present excellent cytomorphology (Figs. 5.14, 5.15) .
When sufficient cellularity and technical support are available
can provide much in the way of additional diagnostic
information. Included among the possibilities are
staining properties that approach what is seen in conventional paraffin-
embedded hematoxylin and eosin (H and E) stained surgical biopsies.
In this manner cell blocks often provide an immeasurable level of
comfort to many pathologists more accustomed to conventional
histologic diagnoses. In particular types of FNA specimens such
as salivary gland cystic lesions and thyroid nodules convention-
ally prepared cells blocks may provide key information to clinch a
A common example is in distinguishing chronic