Cytopathology in Veterinary Dermatology

Source Journal of Veterinary Science
Editorial
Open Access
Cytopathology in Veterinary Dermatology: Improving Sample Diagnostic
Yield
Grandi F1*,2 and Honse C3
Department of Pathology, Botucatu Medical School, Univ. Estadual Paulista – UNESP – Botucatu,Brazil
1
2
Department of Veterinary Clinics, Service of Veterinary Pathology, School of Veterinary Medicine and Animal Science,
Univ. Estadual Paulista, UNESP – Botucatu, Brazil
3
Clinical Research in Infectious Diseases, Oswaldo Cruz Foundation, Brazil
*Corresponding author: Fabrizio Grandi, Laboratory of Investigative and Comparative Pathology, School of
Veterinary Medicine and Animal Science, Univ. Estadual Paulista – UNESP, Botucatu, Brazil, Tel: +55 14 3811 6293;
E-mail: fgrandivet@gmail.com
Introduction
Skin diseases have a wide range of clinical
patterns including plaque, nodules, tumors, vesicles,
Veterinary dermatology is one of the most
bullae,
pustules,
crusts,
erosions,
ulcers,
important medical fields, also the most laborious to
hyperkeratosis, and/or hyperplasia. Commonly, all of
achieve a definitive diagnosis because different
them are superimposed distinctions between primary
diseases can have similar clinical presentations. As
and secondary lesions [2].
stated in book Muller & Kirk’s Small Animal
Cytology is a frequently used diagnostic
Dermatology [1], dermatologic diseases either can be
method in veterinary dermatology by achieving rapid
among the most rewarding conditions treated by
diagnostic results with an excellent cost-benefit ratio,
veterinarians or the most frustrating, since multiple
minimal invasiveness, no anesthesia needed, and low
diagnostic tests may be required to arrive at a definitive
occurrence of adverse effects. On the other hand,
diagnosis. Therefore, mastering diagnostic methods
cytology poses limitations such as no evaluation of
and interpretation are essential for dermatological
surgical margins, extent and depth of lesions and
practice [2].
overall tissue architecture, which represent import
criteria mainly for neoplastic conditions [4,5].
Skin disorders from dog and cats are classified
Sample
collecting
techniques
are
well
into neoplastic and non-neoplastic diseases. Non-
documented in veterinary cytology, posing no difficulty
neoplastic diseases include inflammatory, dysplastic
to professionals. Despite this, obtaining diagnostic
and degenerative ones. Neoplastic diseases include
sample is not always an easy task in part due to the
epithelial and mesenchymal tumors, including round
misleading use of collection techniques for a specific
cell tumors. Virtually all of them can be assessed by
dermatological lesion. Based on this, picking samples
cytopathological
previous
according to a disease-approach method seems
knowledge of normal and abnormal skin structure are
reasonable, in which skin lesions lead to the most
highly desired for cytological interpretation [2,3].
suitable collection technique. Collection techniques
analysis.
Volume 1│Issue 1│2014
Moreover,
a
Page 1 of 3
© 2014 Grandi F et al; licensee Source Journals. This is an open access article is properly cited and
distributed under the terms and conditions of creative commons attribution license which permits unrestricted use, distribution and
reproduction in any medium.
and smear preparation are well described in literature
Scraping
[3-6] and thus, they will not be addressed here.
Cytological smear is made by scraping lesion
Impression Smears
surface with either a sterile scalpel blade or the border
of a clean histological slide. The technique is indicated
Impression smears are made by pressing
in erosive and ulcerative crusted and non-crusted
several times a clean histological slide against surface
lesions, and proliferative diseases. Among those
of an eroded or ulcerated lesion, using different areas
diseases, we can cite actinic keratosis, malassezia
of its glass. A hypodermic needle can be used to
dermatitis, keratinization disorders, round cell tumors
rupture pustules and vesicles prior to imprinting, in
and epithelial neoplasms. Cytological scraping is
order to collect their contents. Ulcers highly crusted
particularly
should be cleaned prior to collection with 0.9% NaCL
differentiated malignant mesenchymal neoplasms with
solution, since diagnostic materials are located below
a
crusts into ulcer bed. Sampling a crust will provide a
collagenous
non-diagnostic material composed of bacteria, cellular
myxomas,
debris
melanocytomas, neural and perineural tumors [3,6].
and
leukocytes,
mainly
neutrophils.
high
useful
amount
for
of
stroma,
those
benign
extracellular
i.e.
and
matrix
fibroma,
well
and/or
fibrosarcomas,
myxosarcoma,
leiomyomas,
Hemorrhagic ulcers should be cleaned with a gauze
prior
collection
to
avoid
excessive
blood
Fine Needle Cytology
contamination, which may render an inconclusive
diagnosis [3,6].
Fine needle cytology (FNC) is used for
This technique is indicated in erosive,
ulcerative, pustular and vesicular skin diseases. The
lesion group includes impetigo, superficial spreading
pyoderma, dermatophytosis, pemphigus foliaceus, drug
reactions, pyotraumatic dermatitis, calcinosis cutis,
superficial and deep bacterial folliculitis, eosinophilic
pustulosis, demodicosis and round-cell ulcerated
neoplasms such as canine venereal transmissible
tumors
(TVT).
Other
mesenchymal
neoplasms,
particularly those rich in extracellular matrix or
collagenous stroma, are more difficult to be sampled
since the technique avoids performing readily cell
exfoliation [1,3,7]. Impression smears can also be used
for Malassezia spp detection.
inflammatory, non-neoplastic and neoplastic disorders
manifested mainly as skin nodules, plaques, tumors
and cysts; eventually vesicles, bullae and pustules can
also be sampled. Among inflammatory diseases,
granulomatous and pyogranulomatous infectious such
those produced by fungal, bacterial, and protozoan
agents can be sampled by this technique; noninfectious granulomatous illnesses such as deep
bacterial folliculitis and furunculosis, acral lick
dermatitis, foreign body reactions, xanthomas, reactive
histiocytosis,
vaccination
eosinophilic
panniculitis,
disorders,
and
post-rabies
sterile
nodular
panniculitis. Among non-neoplastic and neoplastic
tumors, mast cell tumor, melanomas, histiocytomas,
TVT, lymphoma (tumoral phase), plasma cell tumor,
adnexal adenomas and carcinomas, nail bed tumors,
hair follicle tumors, high grade sarcomas, histiocytic
tumors, keratomas, and follicular cysts can be named
[3,4,7].
Volume 1│Issue 1│2014
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© 2014 Grandi F et al; licensee Source Journals. This is an open access article is properly cited and
distributed under the terms and conditions of creative commons attribution license which permits unrestricted use, distribution and
reproduction in any medium.
FNC is divided in aspiration and nonaspiration techniques. On the former, a 10 mL syringe
2. Gross TL, Ihrke PJ, Walder EJ, Affolter VK (2005)
is employed to apply negative pressure in order to
Skin diseases of the dog and cat: clinical and
facilitate cell collection in tissues with a high
histopathologic diagnosis. 2nd edition. Blackwell
extracellular matrix component, mainly collagen. On
Publishing: 625-648.
the latter procedure, it constitutes the first attempt to
collect cells prior employing an aspiration method,
3. Raskin RE, Meyer DJ (2010) Canine and feline
being the only choice for highly vascularized lesions.
cytology: a color atlas and interpretation guide. 2nd
Avoiding central areas of large tumors is important
edition. Saunders, Elsevier Inc.
since those areas frequently have multiple necrotic
centers, which may result in a non-diagnostic sample
4. Grandi F, Beserra HEO, Costa LD (2014)
[3,5,6].
Citopatologia Veterinária Diagnóstica. 1st edition.
Finally, although cytopathology can offer
MedVet.
important diagnostic information, it should keep in
mind histopathological analysis as the outstanding
5. Meinkoth JH, Allison RW (2007) Sample collection
standard
and handling: getting accurate results. Vet Clin Small
method
in
diagnosing
inflammatory,
dysplastic, degenerative and neoplastic skin diseases in
Anim 37: 203-219.
veterinary dermatology.
6. Cowell RL, Tyler RD, Meinkoth JH, DeNicola DB
(2008) Diagnostic cytology and hematology of the dog
References
and cat. 3rd edition. Mosby, Elsevier Inc: 149-171.
1. Miller WH, Griffin CE, Campbell KL (2013) Muller
& Kirk’s small animal dermatology. 7th edition.
7. Sharkey LC, Seelig DM, Overmann J (2014) All
Saunders, Elsevier Inc.
lesions great and small, part 1: diagnostic cytology in
veterinary medicine. Diagn cytopathol 42: 535-543.
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