Ariyarathna H, Aberdein D, Thomson N, Gibson I, Munday J S
Department of Pathobiology, School of Veterinary Science, Massey University, Palmerston North, New Zealand.
IDEXX Laboratories, Palmerston North, New Zealand.
N Z Vet J. 2022 Mar;70(2):95-100. doi: 10.1080/00480169.2021.2004953. Epub 2021 Dec 6.
To evaluate the proportions of canine mammary gland lesions submitted to a New Zealand diagnostic laboratory, that were neoplastic non-neoplastic and, among neoplasms, malignant benign, and to determine whether age, reproductive status or breed of dog, or size of the mammary mass were associated with the histological diagnosis.
Canine mammary gland biopsies submitted between the start of 2012 and the end of 2016 were selected from the surgical biopsy database of IDEXX Laboratories, NZ. For each case, details on age, breed, and reproductive status of the patient were registered as reported by the submitting veterinarians, along with the size (classified as small, medium or large) of the lesion and the histological diagnosis reported by the pathologists. tests and independent sample t-tests were performed to evaluate associations.
Samples (n = 895) were submitted from 797 dogs, of which 673 had mammary neoplasms while 124 had non-neoplastic lesions. Neoplasms composed of a single nodule were found in 591/673 (87.8%) dogs, while 82/673 (12.2%) dogs had multiple nodules. Of the total 771 neoplasms, 432 (56.0%) were histologically malignant, while 339 (44.0%) were benign. Among malignancies, the most common histological sub-types were simple carcinoma (160/771; 20.8%), complex carcinoma (54/771; 7%), and ductal carcinoma (32/771; 4.2%), while benign mixed mammary tumour (128/771, 16.6%) and complex adenoma (105/771; 13.6%) were the most frequently reported benign mammary neoplasms. There was no evidence of a difference in age (p = 0.09) or reproductive status (p = 0.79) of the dog or the size of the mass (p = 0.21) between neoplastic and non-neoplastic lesions. However, neoplastic mammary gland lesions were more frequent in purebred dogs (612/671; 91.2%) than crossbred dogs (61/126; 48.4%; p < 0.001). There was no evidence of a difference in age (p = 0.15) reproductive status (p = 0.36) or breed (p = 0.45) of dog between malignant and benign neoplasms. There was an association between size and histological benign or malignant status of a neoplasm ( = 0.65, p < 0.001).
Most canine mammary gland samples submitted for examination were neoplastic with slightly more malignant than benign lesions. Masses submitted from purebred dogs were more likely to be neoplastic, while large neoplasms were more likely to be malignant.
The present findings provide the first description of the distribution of mammary gland lesions in a relatively large number of dogs in New Zealand, representing a preliminary investigation of canine mammary gland diseases in this country.
评估提交至新西兰一家诊断实验室的犬乳腺病变中肿瘤性、非肿瘤性病变的比例，以及肿瘤中恶性、良性病变的比例，并确定犬的年龄、生殖状态、品种或乳腺肿块大小是否与组织学诊断相关。
从新西兰IDEXX实验室的手术活检数据库中选取2012年初至2016年末提交的犬乳腺活检样本。对于每个病例，记录提交兽医报告的患者年龄、品种和生殖状态细节，以及病变大小（分为小、中或大）和病理学家报告的组织学诊断。进行检验和独立样本t检验以评估相关性。
共收到来自797只犬的样本（n = 895），其中673只患有乳腺肿瘤，124只患有非肿瘤性病变。673只患肿瘤的犬中，591只（87.8%）的肿瘤由单个结节组成，82只（12.2%）有多个结节。在总共771个肿瘤中，432个（56.0%）组织学上为恶性，339个（44.0%）为良性。在恶性肿瘤中，最常见的组织学亚型为单纯癌（160/771；20.8%）、复杂癌（54/771；7%）和导管癌（32/771；4.2%），而良性混合乳腺肿瘤（128/771，16.6%）和复杂腺瘤（105/771；13.6%）是最常报告的良性乳腺肿瘤。在肿瘤性和非肿瘤性病变之间，犬的年龄（p = 0.09）、生殖状态（p = 0.79）或肿块大小（p = 0.21）没有差异证据。然而，纯种犬的乳腺肿瘤性病变（612/671；91.2%）比杂种犬（61/126；48.4%）更常见（p < 0.001）。在恶性和良性肿瘤之间，犬的年龄（p = 0.15）、生殖状态（p = 0.36）或品种（p = 0.45）没有差异证据。肿瘤大小与肿瘤的组织学良性或恶性状态之间存在关联（ = 0.65，p < 0.001）。
提交检查的大多数犬乳腺样本为肿瘤性，恶性病变略多于良性病变。纯种犬提交的肿块更可能是肿瘤性的，而大肿瘤更可能是恶性的。
本研究结果首次描述了新西兰相对大量犬乳腺病变的分布情况，代表了该国犬乳腺疾病的初步调查。
