https://doi.org/10.52973/rcfcv-e33244
Received: 12/04/2023 Accepted: 09/06/2023 Published: 03/07/2023
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Revista Científica, FCV-LUZ / Vol. XXXIII, rcfcv-e33244, 1 – 8
ABSTRACT
In this work it was examined the concordance between clinical
staging and histopathological staging of mammary tumors in 32
female dogs. It was observed that the average age of presentation
of the pathology was 9 years (ranged from 6 to 12 years). The most
affected mammary glands were the caudal abdominal and the inguinal,
20 out of 32 female dogs had multiple tumors (62%), and 38% single
tumors. Regarding the breeds, the most frequent ones were mixed
breeds, Poodle, Cimarron (native breed of Uruguay) and Labrador
Retriever. Of the 32 female dogs with breast tumors studied, 65%
had histopathological diagnosis of malignant tumor, while 35% had
benign tumors. Clinical staging data showed that 64% of the cases
with benign tumors were in stage I (1 to 3 cm) and 36% were in stage II
(3 to 5 cm). Among those diagnosed with malignant tumors, 10% were
in stage V, 57% in stage III, 9% in stage II, and 24% in stage I. There
were no animals in stage IV. The most frequently found malignant
tumors were tubular carcinoma and complex carcinoma, followed
by solid and tubulopapillary carcinomas. Within the benign tumors,
complex adenoma was the most frequent, followed by benign mixed
tumor and simple ductal papilloma. The concordance between clinical
staging and histopathology was low, as we could observe both benign
T2 (3 to 5 cm) and malignant T1 (1 to 3 cm) tumors.
Key words: Canine mammary tumors; mammary tumor
histopathology; clinical staging in mammary tumors
RESUMEN
En el presente trabajo se evaluó la concordancia entre la estadicación
clínica y la clasicación histopatológica de tumores de mamas en
32 perras. Se observó que la edad promedio de presentación de
la patología fue de 9 años. Las mamas más afectadas fueron los
abdominales caudales, e inguinales, 20 de las 32 perras presentaban
tumores múltiples (62 %) y un 38 % tumores únicos. Con respecto a las
razas, las más representativas fueron mestizos, Caniche, Cimarrón (raza
autóctona de Uruguay) y Labrador. De las 32 perras estudiadas con
tumores de mama, el 65 % (21) tuvieron diagnóstico histopatológico de
tumor maligno, mientras que el 35 % (11) fueron catalogados benignos.
Con los datos de la estadicación clínica se pudo observar que el
64 % de las perras que presentaron tumores benignos se encontraban
en estadio I (1 a 3 cm) y 36 % se encontraban en estadio II (3 a 5 cm).
Dentro de las perras que desarrollaron un diagnóstico de tumores
malignos, el 57 % se encontraban en estadio III, el 9 % en estadio II y
24 % en estadio I. En el presente estudio no se obtuvieron animales
que se encontraran en estadio IV y un 10 % estaban en estadio V de la
enfermedad. Los tumores malignos encontrados con más frecuencia
fueron el carcinoma tubular y el carcinoma complejo, seguido por el
carcinoma sólido y el túbulo papilar. Dentro de los tumores benignos
se destacó con mayor frecuencia el adenoma complejo seguido por
el tumor benigno mixto y el papiloma ductal simple. Respecto de la
concordancia entre la estadicación clínica y la histopatología, fue
bajo dado que se observaron tumores benignos T2 (de 3 a 5 cm) y
tumores malignos T1 (1 a 3 cm).
Palabras clave: Tumores mamarios caninos; histopatología de
tumores de mama; estadio clínico en tumores
mamarios
Concordance between clinical presentation and histopathological staging
canine mammary tumors
Concordancia entre la presentación clínica y la estadicación histopatológica en
tumores mamarios caninos
Alicia Decuadro
1
* , Alejandro Benech
1
, Silvia Llambí
2
, Rosa Gagliardi
2
†
1
Veterinary Faculty Hospital. Montevideo, Uruguay.
2
Genetics and animal improvement Unit, Veterinary Faculty. Montevideo, Uruguay.
*Corresponding Author: consultaoncovet@gmail.com
Canine mammary tumors clinical and histopathology / Decuadro et al. _____________________________________________________________
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INTRODUCTION
Breast tumors are the most frequent neoplasms in intact female
dogs (Canis lupus familiaris) accounting for about half of oncologic
cases [1, 2, 3]. They correlate with life expectancy and their incidence
is signicantly reduced by ovariohysterectomy (spaying) in young
female dogs, as their development is clearly hormone–dependent.
[4]. Compared to intact female dogs, the risk for malignant tumors
in dogs spayed before the rst estrus is 0.5%, it increases to 8% if
spaying is performed after the rst estrus, and to 26% if spaying is
performed after the second estrus [4, 5, 6, 7]. When performed later,
spaying does not reduce the risk of malignant tumors, although it
does appear to be a reduced risk for benign tumors [8, 9, 10]. The
average age of affected female dogs is 10 to 11 years (range: 2 to 16)
[11]. Younger female dogs usually have benign tumors, while malignant
tumors tend to occur at more advanced ages. Approximately half of
the canine mammary tumors are malignant, and half of them have
metastasized by the time of the initial diagnosis [10, 11].
The stablished staging system was proposed by Owen et al. [12] for
the World Health Organization (WHO). It is based on the Classication
of Malignant Tumors (TNM) system, by which animals are categorized
into ve stages according to tumor size and attachment to adjacent
tissue (T), spread to nearby lymph nodes (N), and distant metastasis (M).
Therefore, staging should include minimum database, consist al.ting
of, chest X–ray (three images: dorsoventral, right laterolateral and
left laterolateral), abdominal ultrasound, full blood count, serum
biochemistry panel, urinalysis, and assessment of regional lymph
nodes by palpation. If enlarged, axillary and inguinal lymph nodes
should be palpated and aspirated for cytological analysis [11]
Clinical staging allows to dene the extent of the disease and,
consequently, establish a prognosis and treatment plan [13].
According to Vail et al. [14], the transition from T1 to T2 and from
T2 to T3 worsens the prognosis of the disease and implies changes
in the treatment. Regardless of tumor size, metastases in regional
lymph nodes or distant metastases cause any clinical stage to raise
to stage IV or V, respectively.
The WHO classication with respect to the histopathological study
follows the differentiation process, starting with malignant tumors
that most closely resemble the normal structure of the mammary
gland and ending with poorly differentiated tumors with no glandular
structure. Previous classications did not include inammatory
carcinomas, because they were not considered to be a specic
histological subtype, but just any breast carcinoma with marked
inammation [15]. In the new classication of Goldsmith et al. [16],
inammatory carcinoma became a specic entity. This histological
classication of breast tumors in female dogs was validated in 2017
by Rasotto et al. [17], where a population of 229 female dogs was
followed up for two years to determine survival times of each subtype,
rate of local recurrence, and distant metastases [16, 17].
Among the reasons for performing the histopathological
classication of breast tumors is the objective of evaluating the
architecture of the neoplasm and the morphological variations of
the nucleus, the histological grade, which represents a signicant
correlation with the aggressiveness of the tumor [18].
In Human Medicine, currently the most widely used classication
system is the Nottingham classication system modied by Elston and
Ellis [18], which has replaced previous subjective evaluations when
the degree of tumor differentiation was estimated by the general
appearance of the tumor. According to this system, determination
of the histological grade is based on: the evaluation of the index
of tubules formation (one point: more than 75% of the tumor is
composed of tubules, two points: between 10 and 75% of tubular
formations, and three points: the tubules occupy 10% or less of the
tumor); nuclear pleomorphism (one point: small and regular nuclei;
two points: moderate increase in size and variation of nuclei; three
points: marked pleomorphism, with great variation in size and shape
of nuclei); and mitotic count (one point: 0–8 mitoses, two points:
9–16 mitoses, and three points: more than 17 mitoses in 40X lens).
The histological grade of the tumor is obtained through the sum of
the scores, which results in a total number ranging between 3 and 9.
The summary of the tumor grades is: 3–5 points: grade I; 6–7 points:
grade II; 8–9 points: grade III. Anaplasia increases with increasing
grade. Histological grade is considered as an independent prognostic
indicator for primary breast tumor in women. The malignancy degree
is based not only on the tumor type but also on the presence of
signicant cellular pleomorphism, mitotic index, the presence of
necrotic areas, peritumoral and lymphatic invasion, and regional
lymph node metastases [16, 18, 19].
Cases of undifferentiated carcinoma (grade III) had a 21–fold increased
risk of death compared to cases of differentiated carcinoma (grade I and
II). An increased risk (approximately 10–fold) was also associated with
simple undifferentiated carcinomas compared with differentiated ones.
The predictive value of histological grade was not inuenced by the
size of the tumor or the age of the dog at the time of mastectomy [20].
Regarding canines, recently, the number of veterinary investigators
who have adopted the histological staging criteria proposed by
Nottingham to evaluate mammary carcinomas in dogs has increased.
According to the available literature, the use of clinical staging
criteria TNM and evaluation of classical morphologic prognostic
factors (tumor size, mitotic count, histologic grade and type, and
lymphatic involvement), well established in humans, are useful in
evaluating the prognosis of female dogs with mammary carcinomas.
Therefore, diagnostic criteria need to be improved and standardized,
and continued investment in the study of prognostic and predictive
markers is needed for these factors to be routinely employed by
veterinary pathologists and provided to clinicians and surgeons. The
goal is not to subject patients to unnecessary aggressive treatment
or to stop treating those who would benet. The quality of life of the
animal should always be prioritized [19].
The aim of this study was to determine the concordance between
clinical ndings and histopathological classication in breast tumors
in dogs. There are still no studies that have evaluated the effectiveness
of clinical staging as a predictor of histopathological classication.
MATERIALS AND METHODS
This work was carried out at the Hospital of the Faculty of Veterinary
Medicine of the University of the Republic, Uruguay. It was approved
by the Ethics and Animal Use Committee under No. 518.
The Hospital of the Veterinary School has the necessary facilities
for clinical care and obtaining samples. Blood studies were made at
the Clinical Analysis Laboratory (equipment CB30i Wiener–lab Group,
Argentina). Blood samples were obtained (3 mL) from the cephalic
vein with a 21 G buttery by the veterinary nurse
This samples were divided into two tubes: 1 mL in
Ethylenediaminetetraacetic acid (EDTA) tube for complete blood
FIGURE 1 (A). Unilateral radical mastectomy. B) regional mastectomy
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count and the 2 mL remaining in a dry tube to determine creatinine
urea and liver function.
Thoracic radiographs were obtained in a Vetter Rems 100 device
(Argentina) and digitalized in a Kodak DirectView, Sistem Classic CR
Caresream (Japan) positioning the patient in lateral decubitus and
sternal decubitus, in order to get latero–lateral and dorso–ventral
views. The images were evaluated by the veterinary radiologists of
the Imaging Unit of Veterinary School.
Histopathology was performed at the Eastern Regional Laboratory
(DILAVE MGAP), with an Olympus BX51 microscope (Japan) using
hematoxylin and eosin (H–E) staining at 40X and 10X magnication.
The study included 32 female dogs admitted to the hospital over a one
year period. The case selection criteria were intact (not spayed) female
dogs with palpation–detectable mammary tumors. No distinction of
breed was made. It was also took into account that the staging of the
disease and pre–surgical studies would allow mastectomy (ASA I or II).
Case history was carried out through a survey that included
data such as age, breed, and reproductive status, as well as tumor
characteristics such as location, size, and whether it was single or
multiple. In each patient, a thorough physical examination was carried
out, including individual inspection and palpation of each breast of
both chains, and of the regional lymph nodes (axillary and inguinal).
Staging of the patients was performed using the WHO staging system.
Pre–surgical evaluation included chest x–rays (left–lateral, right–
lateral, and ventro–dorsal), blood count, blood biochemistry (renal
and hepatic functional prole), and urinalysis. In all cases, surgical
removal was the treatment of choice. Surgical techniques used were:
regional mastectomy, unilateral or bilateral radical mastectomy.
The choice of the appropriate technique depended on the size of
the tumor, the number of affected mammary glands, the location,
xation to the surrounding tissues and health status of the patient.
Surgeries were performed by the veterinary surgeon team from the
Veterinary School. (FIG. 1)
Following this procedure, tumors were xed in 10% formalin on
paran–embedded 1.5 × 1.5 centimeters (cm) sections and stained
with H–E.
For histological examination, tumor samples were in xed in 4%
neutral buffered formalin, embedded in paran, sectioned at 5–7 μm
(microtome RM2125 RTS, Leica Microsystems) and stained with H–E
(slide stainer Shandon Varistain 24–4). The rates of mitotic cells were
calculated by counting them in several randomly high–magnication
elds (40X) per tumor. The mammary tumors were histologically
classied and grading according to the new system proposed by
Goldschmidt et al. [16].
Statistical analysis
The evaluation of concordance between the clinical staging
and the histopathological classication of the tumors was carried
out using the weighted Kappa Index [21] since it is applicable to
qualitative variables with more than 2 categories among which
there is a hierarchical order (qualitative variables of ordinal scale).
In this situation, there may exist varying degrees of agreement or
disagreement between the clinical and histopathological evaluations.
The weighted Kappa Index considers the agreement between the
tests (clinical vs. histopathology) on the diagonal and penalizes (in
a weighted way) the disagreement according to the distance to the
diagonal of agreement.
RESULTS AND DISCUSSION
Results in mammary tumors
The age of presentation of mammary tumors in this study ranged
from 6 to 12 years with an average of 9 years. There was no differences
in tumor location between both mammary chains, 51% of tumors were
located in the right–side chain, while 49% were distributed in the
left–side chain. The breasts with most tumors were the inguinal ones
(11/32), followed by caudal abdominal (8/32), cranial abdominal (8/32),
and caudal thoracic (4/32) breasts. In the case of cranial thoracic
breasts, a single tumor was found in just one patient. In 62% of the
cases (n=20), the presentation of the tumors was multiple. No female
presents benign and malignant tumors within the same mammary
chain but this can be attributed to the low number of the sample,
and in 38% of the cases (n=12) they were single tumors. In terms of
tumor malignancy, 35% (n=21) were malignant, while 11% (n=65) were
benign. Of the female dogs with multiple tumors, 15 were malignant
and 4 benign, of those with single tumors, 7 were malignant and 5
benign. Clinical staging data showed that 64% of female dogs with
benign tumors had stage I (1 to 3 cm), and 36% had stage II (3 to 5 cm).
Among the female dogs diagnosed with malignant tumors, 57% were
A
B
A
A
B
B
FIGURE 2. A: Histopathological sample of a simple tubular carcinoma, H–E staining
10X. B: Histopathological sample of a complex carcinoma, H–E staining 10X
FIGURE 3. A: Comedocarcinoma 40X. B: Tubulopapillary carcinoma. Hematoxilyn
and eosin staining 10X
Canine mammary tumors clinical and histopathology / Decuadro et al. _____________________________________________________________
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in stage III, 9% in stage II, and 24% in stage I. In this study, no animals
were found in stage IV (lymph node metastases) which was discarded
by cytology, and 10% were in stage V disease (lung metastases).
Histopathology of mammary tumors
Among malignant tumors, the most frequents in this study were
simple tubular carcinoma and complex carcinoma, both with equal
numbers (n=4 each), followed by solid and tubulopapillary papillary
tubule carcinomas (n=2 each) and, with one case of each type, by
simple carcinoma, cystic papillary carcinoma, comedocarcinoma,
anaplastic carcinoma, mixed carcinoma, intraductal papillary
carcinoma, malignant myoepithelioma, lipid–rich carcinoma, and
inammatory carcinoma (FIGS. 2, 3,4 and 5).
Following the classification of Goldsmith et al. [16], of the 21
malignant tumors, malignant epithelial tumors accounted for 85.7%
(18/21), whereas those of special types accounted for 14.3% (3/21).
Among the histopathological grade I malignant tumors, It was found
only one female dog with an intraductal papillary carcinoma. Among
the histopathological grade II, It was found seven female dogs with the
following tumor types: tubulopapillary carcinoma, complex carcinoma,
mixed carcinoma, simple tubular carcinoma and lipid–rich carcinoma.
As for histopathological grade III, there were 13 female dogs with
the following carcinomas, in order of frequency: simple tubular
carcinoma, complex carcinoma, solid carcinoma, inammatory
carcinoma, anaplastic carcinoma, malignant myoepithelioma and
papillary cystic carcinoma. (TABLE I). Four of these female dogs with
malignant tumors were ulcerated. None of the tumors was attached
to deep planes. Among the benign tumors, complex adenoma (8
patients) was the most frequent, followed by benign mixed tumor
(two patients) and simple ductal papilloma (one patient).
A
B
FIGURE 4. A: Histopathology of a mixed carcinoma, 40X. B: Lipid–rich carcinoma.
H–E staining 10X
FIGURE 5. Histopathology of lymphatic emboli located in the dermis of an
inammatory carcinoma. H–E 40X
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Concordance analysis between diagnostic methods.
The estimate of Cohen's weighted Kappa index, with a 95%
condence interval, was: k = 0.48 [0.16 – 0.81]. Since this index is given
values between 0 and 1, in the present case the degree of agreement
observed was weak to moderate. When analyzing the possible cause
of the low concordance obtained between the tests, It was found that
the proportion of agreement observed was Po = 12/32= 0.375 (37.5%),
which indicates a low linear association between the clinical and
histopathological diagnoses.
In the following Table (TABLE II) the tumors in each stage were shown.
TABLE I
Relationship between Histopathological Type and Histopathological Grade
Histopathological type
Histopathological grade
Grade I (n) Grade II (n) Grade III (n)
Inammatory carcinoma – – 1
Comedocarcinoma – – 1
Carcinoma mixed type – 2 –
Carcinoma tubular simple – 1 3
Carcinoma complex – 1 1
Carcinoma anaplastic – 2 2
Carcinoma solid – – 2
Malignant myoepithelioma – – 1
Intaductual papillary carcinoma 1 – –
Lipid rich carcinoma – 1 –
Carcinoma cystic papilar – – 1
Total 1 7 13
TABLE II
Concordance Analysis between Diagnostic
Methods: Histopathological Vs Clinical
HG 0 HG 1 HG 2 HG 3
CS 0 0 0 0 0
CS 1 7 0 2 3
CS 2 4 0 2 0
CS 3 0 1 3 10
Number of tumors classied in each stage according to the two
diagnostic methods simultaneously (clinical and histopathological).
GH 0 was used for benign tumors. Clinical stages 4 and 5 were linked
to stage 3 due to their low n. The proportion of agreement (accuracy)
is 12/32= 37.5%, which indicates a low linear association, for which
the concordance between the clinical and histopathological diagnosis
is low. CS: clinical stage; HG histopathological grade.
In rst place, regarding the age of presentation of mammary tumors,
it was between 6 and 12 years, with an average of 9 years. TABLE III.
Canine mammary tumors clinical and histopathology / Decuadro et al. _____________________________________________________________
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These values agreed with those of various authors [10, 11, 14, 22, 23].
It has been previously reported that two–thirds of mammary tumors
occur in the caudal abdominal and inguinal breasts, probably due to
their greater volume of breast tissue, while thoracic breast tumors
are less frequent [14, 19, 24]. In this paper, the data agree with what
has been previously described. Only one of the 32 female dogs studied
had a single tumor in the right caudal thoracic mammary gland. Four
had tumors in the caudal thoracic mammary glands, but these were
cases of multiple tumors involving several breasts in the chain. In
the remaining dogs, the breasts more frequently affected were the
caudal abdominal and the inguinal breasts. This leads to consider the
fact that at least 50% of female dogs with mammary neoplasms have
multiple tumor masses [11]. In the present study, 20 of the 32 female
dogs had multiple tumors, accounting for 62% of the cases. There
is no consensus regarding the breeds with the highest incidence of
breast tumors, the risk varies according to the study and geographic
location [10, 11, 25, 26, 27]. Burrai et al. [23] observed that small
breeds had predominantly benign tumors, particularly in Yorkshire
Terrier, while malignant tumors were more frequently detected in
German Shepherd dogs. Here, it was observed a higher percentage
of benign tumors in the Poodle and German Shepherd breeds; this
may be due to the previously mentioned factors, and it should also be
taken into account that, as this paper had a low number of animals
of each breed, these data may not be comparable.
Histopathological diagnosis before surgery is not a common
practice in Veterinary Medicine, except in Veterinary Reference
Centers but it is performed after surgical removal. This is because
there are usually multiple tumors that could correspond to different
mammary neoplasms, therefore, it would be necessary to take one
sample from each one of them. With regard to ne needle aspiration
(FNA), it should be added that there is a great cellular heterogeneity,
which could give rise to a discrepancy in the case of samples as small
as those obtained by this method. Another point to bear in mind is
that regardless of the outcome of the histopathological analysis,
the therapeutic modality will be the same (surgical). FNA would be
indicated only for cases of differential diagnosis such as lipomas,
mastocytomas, and inammatory carcinomas [13]. Due to the above
stated reasons, in the Specialized Oncology Clinic of the Veterinary
Hospital of the University of the Republic, mammary tumors are
diagnosed by histopathology after the surgical procedure, since
neither routine FNA nor breast biopsies are performed.
The percentage of female dogs with malignant tumors (65%) in
this study is slightly above those reported by other authors, which
range between 43 and 51% [1, 2, 3, 23]. According to Ferreira et al.
[28], most lesions larger than 5 cm (T3) are malignant, with higher
proliferation rate than those of smaller tumors (T1, T2); these data are
consistent with our ndings in this study, where 66.7% of T3 tumors
were malignant. According to Camargo et al. [29], regarding tumor
size, T3 lesions were predominantly associated with carcinosarcomas,
while T1 and T2 lesions were more frequent in benign mixed tumors
and mixed carcinomas within malignant tumors. Burrai et al. [23]
observed a 2.3– and 3.6–fold increase in the odds of a malignant
tumor when moving from T1 to T2 and from T2 to T3, respectively.
These authors evaluated 1,866 female dogs with single breast tumors
and observed 73% T1, 16.6% T2, and 10.3% T3. 89.65% of the canine
mammary tumors were between 0 and 5 cm, and 63.76% of the
malignant tumors were smaller than 3 cm, of which 62.5% were
classied as simple carcinomas. T2 and T3 types included 21. 32%
and 14.91% of mammary tumors. These data are consistent with
the ndings of this work, where we also observed both T1 and T2
malignant tumors, and the most observed histopathological type
was also simple carcinoma. Within T1, it was found both benign and
malignant tumors. Among the benign tumors, by decreasing order
of frequency it was found in rst place complex adenoma, followed
by benign mixed tumor and ductal papilloma.
Among the malignant tumors, it was observed mixed carcinoma,
comedocarcinoma, and complex carcinoma. In clinical stage T2, it was
also observed malignant and benign tumors. Malignant tumors were
mixed carcinoma and complex carcinoma, while complex adenoma
was the most representative benign tumor. There were no tumors
classied as carcinosarcoma; the most representative T3 tumors
were simple tubular carcinoma and papillary tubular carcinoma,
followed by inammatory carcinoma, anaplastic carcinoma, malignant
myoepithelioma, complex carcinoma, papillary intraductal carcinoma,
and lipid–rich carcinoma. We also observed a high number of
malignant breast tumors smaller than 1 cm, thus suggesting the need
to reconsider the size (T) parameter in the TNM system, paving the
way for the development of tools for clinical research and control by
assessing risk factors for small–sized tumors. These T1 tumors were
found to be high grade, and were classied as comedocarcinomas
and solid carcinomas. When comparing female dogs with stage I
and II tumors with those staged in stage V, the latter had a worse
prognosis, coinciding with Karayannopoulou et al. [20]. In this study,
two of the female dogs were in stage V at the time of diagnosis, with
complex carcinoma and papillary cystic carcinoma. Among the female
dogs with malignant tumors, four had ulcerated tumors, which are
often considered as an indicator of malignancy. This is controversial,
since according to Hellmén et al. [30] ulceration and necrosis are
two features that have been suggested as indicators of increased
tumor aggressiveness. But it is also possible to think that they may
be often due to self–induced trauma, ischemia, or skin infection,
characteristics that are not necessarily associated with an aggressive
biological behavior of the tumor.
According to Vail et al. [14], the evaluation of regional lymph nodes
has a major impact on the survival of dogs with canine mammary
tumors (CMT), as they show a significant decrease in survival
compared with those who tested negative for lymph node metastases.
In this study, no patients with lymph node metastases were found.
Two of the female dogs had lung metastases, coinciding with the
literature where it is said that lungs are the most frequent site of
distant metastases [14, 31].
TABLE III
Distribution Of Benign And Malignant Tumors Classied By Age
Age (years) Benign Malignant Total
6 1 2 3
7 0 0 0
8 3 4 7
9 1 1 2
10 2 7 9
11 2 0 2
12 2 7 9
Total 11 21 32
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As mentioned above, with the results of the statistical analysis it
was found a moderate agreement regarding the concordance between
clinical and histopathological staging. Cohen's weighted Kappa index,
with a 95% condence interval, was k = 0.48 [0.16 – 0.81]. These data
are consistent with histopathological results, since it was found both
malignant T1 (1 to 3 cm) tumors and benign T2 (3 to 5 cm) tumors.
CONCLUSIONS
In the present work, the concordance between clinical aspect of the
tumor and histopathology was low, since malignant tumors of small size
(classied as T1: 1 to 3 cm) and benign tumors of low size (classied as
T2: 3 to 5 cm) were found. It seems that clinically there is a tendency to
classify tumors towards greater severity. Studies with a larger population
size are required to obtain more consistent conclusions.
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