Hayden D W, Barnes D M, Johnson K H
Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Minnesota, St. Paul.
Vet Pathol. 1989 Mar;26(2):104-13. doi: 10.1177/030098588902600202.
Abnormal mammary gland growth is a side effect of progestin therapy in some cats. In this retrospective study, the nature and significance of morphologic changes in the mammary gland of 17 megestrol acetate (MA)-treated cats were compared to mammary lesions in 97 untreated cats. Fourteen out of 17 MA-treated cats had non-neoplastic mammary lesions including fibroepithelial hyperplasia (nine cats), lobular hyperplasia (three cats), and duct ectasia (two cats); whereas three MA-treated cats had mammary neoplasms including one adenoma and two carcinomas. Although MA has been causally linked to mammary cancer in cats, only mammary fibroepithelial hyperplasia was clearly associated with MA therapy in this study. Fibroepithelial hyperplasia occurred in older (average age 8.1 years) neutered male and female cats in the MA-treated group and in younger (average age 2.1 years) female cats in the untreated group. Morphologically, both intraductal and solid fibroepithelial growth patterns were seen. Intraductal fibroepithelial hyperplasia was further subdivided into papillary and circumferential types. An apparent greater association between MA therapy and the intraductal types of fibroepithelial hyperplasia was noted. Furthermore, it appears likely that mammary lobular hyperplasia also is linked to MA therapy. Possible mammatrophic effects of MA and other growth-promoting agents in the cat are discussed.
在一些猫中，乳腺异常生长是孕激素治疗的副作用。在这项回顾性研究中，将17只接受醋酸甲地孕酮（MA）治疗的猫的乳腺形态学变化的性质和意义与97只未治疗猫的乳腺病变进行了比较。17只接受MA治疗的猫中有14只患有非肿瘤性乳腺病变，包括纤维上皮增生（9只猫）、小叶增生（3只猫）和导管扩张（2只猫）；而3只接受MA治疗的猫患有乳腺肿瘤，包括1例腺瘤和2例癌。虽然MA已被认为与猫的乳腺癌有因果关系，但在本研究中，只有乳腺纤维上皮增生与MA治疗明显相关。纤维上皮增生发生在接受MA治疗组的年龄较大（平均年龄8.1岁）的绝育雄性和雌性猫以及未治疗组年龄较小（平均年龄2.1岁）的雌性猫中。在形态学上，观察到导管内和实性纤维上皮生长模式。导管内纤维上皮增生进一步细分为乳头状和环状类型。注意到MA治疗与导管内类型的纤维上皮增生之间存在明显更强的关联。此外，乳腺小叶增生似乎也与MA治疗有关。讨论了MA和其他生长促进剂对猫可能的促乳腺生长作用。
