Fine‐Needle Aspiration Biopsy of Canine Mammary Gland Tumours: A Comparison Between Cytology and Histopathology

Abstract

In the current study, a total of 90 mammary neoplasms obtained from 55 female dogs were used to determine the accuracy of fine-needle aspiration cytology in the diagnosis of canine mammary tumours and to investigate the feasibility of this technique for the differentiation of simple tumours from complex or mixed tumours. Three aspirations were performed on each mammary gland mass using a 22-gauge needle attached to a 5-ml syringe before the mammary glands were surgically excised and submitted for histopathological examination. Twenty-five (27.7%) of 90 samples were classified as insufficient/inadequate for diagnosis. Of the remaining 65 samples, six (9.2%) were benign, 51 (78.5%) were malignant tumours and 8 (12.3%) were suspicious. Histopathological examination of the 90 specimens revealed five (5.6%) benign, 84 (93.3%) malignant and one (1.1%) non-neoplastic lesion. The diagnostic accuracy, sensitivity and specificity of cytologic examination for diagnosing malignancy were 96.5%, 96.2% and 100%, respectively. However, when inadequate (n = 25) and suspicious (n = 8) samples were included, the diagnostic accuracy and sensitivity decreased to 63.3% and 60.7%, respectively, but no change was observed in the specificity. Furthermore, it was not possible to differentiate simple tumours from complex and mixed tumours because spindle cells were seen in both 28% of the simple tumours and 39.3% of the complex or mix tumours. In conclusion, we believe that fine-needle aspiration cytology of canine mammary tumours is a valuable diagnostic tool, although our results indicated lower accuracy when inadequate samples were taken into consideration.

Reproductive System

“…In another study, the sensitivity for cytologic detection of mammary malignancies was found to be 65% with a specificity of 94% (Hellman and Lindgren, 1989). Similar results were found in other studies (Simon et al, 2009;Sontas et al, 2012). In a recent study, cytologic and histologic diagnostic agreement was 67.5%.…”

“…Some studies (Allen et al, 1986;Cassali et al, 2007;Hellman and Lindgren, 1989;Simon et al, 2009;Sontas et al, 2012) have examined the accuracy of cytology for detecting mammary malignancies as compared to histologic findings. Allen et al (1986) reported cytologic sensitivities for detecting malignancies of 25% and 17% and specificities of 62% and 49% for the two cytopathologists involved in the study.…”

“…PPV was reported as 93%, NPV as 67%, and diagnostic accuracy as 79%. FNA cytology of canine mammary tumors appears to be a valuable diagnostic tool, although lower accuracy exists when inadequate samples are taken into consideration (Sontas et al, 2012). However, when suspicious and insufficient/inadequate samples were excluded, a 92.9% agreement rate was obtained (Cassali et al, 2007).…”

Diagnostic value of cytological analysis of tumours and tumour-like lesions of the oral cavity in dogs and cats: A prospective study on 114 cases

“…The results of cytology correlate well with histopathological findings for many tumours Ghisleni et al, 2006;Simon et al, 2009) including angiosarcoma, mammary tumours, and osteosarcoma in dogs (Allen et al, 1986;Bertazzolo et al, 2005;Reinhardt et al, 2005;Simeonov and Stoikov, 2006;Simon et al, 2009;Sontas et al, 2012), as well as thymoma, lymph node and splenic lesions, and abdominal, cutaneous or subcutaneous masses in dogs and cats (Ménard et al, 1986;Rae et al, 1989;Chalita et al, 2001;Bonfanti et al, 2004;Ghisleni et al, 2006;Ovejero Braun and Hauser, 2007). However, the diagnostic reliability of cytology in the evaluation of oral masses has not been previously investigated in dogs and cats.…”

Risk Factors and Diagnostic Accuracy of Clinical Findings for Meniscal Disease in Dogs With Cranial Cruciate Ligament Disease

“…This is somewhat typical of other commonly used diagnostic tests. For example, cytology of the mammary gland is not as accurate (63.3%) at detecting malignant mammary tumors as the combination of pain on flexion and meniscal click is at discriminating meniscal tears . Additionally, CT arthrograms have been reported as low as 57% sensitive and 71% specific for detecting meniscal tears clinically .…”