Description of the prevalence, histologic characteristics, concomitant abnormalities, and outcomes of mammary gland tumors in companion rats (Rattus norvegicus)

100 cases (1990–2015)

Claire Vergneau-Grosset, Michael K Keel, Dayna Goldsmith, Philip H Kass, Joanne R Paul-Murphy, Michelle Hawkins

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

OBJECTIVE To describe the prevalence, histologic characteristics, concomitant abnormalities, and outcomes for various types of mammary gland tumors in companion rats (Rattus norvegicus). DESIGN Retrospective case series. ANIMALS 100 client-owned rats. PROCEDURES Medical records of companion rats that had an SC mass and were examined at a veterinary teaching hospital between 1990 and 2015 were reviewed. Information regarding the signalment, age at mass detection, reproductive sterilization status, histologic diagnosis of the SC mass, location of the initial and all subsequent SC masses, treatments administered, and clinical outcomes was extracted from each record and summarized. RESULTS 105 SC masses were initially detected in 100 rats. The most prevalent SC mass identified was mammary gland fibroadenoma (56/105 [53%]), followed by mammary gland carcinoma (13/105 [12%]). Overall, 26 of 105 (25%) masses were malignant. Sexually intact males were more likely to have nonmammary SC tumors than sexually intact females. In rats receiving no adjunctive treatment after excision of a mammary gland fibroadenoma (n = 16), a second fibroadenoma was detected 1 to 8 months after initial excision, at a median of 4.5 months after surgery. A concomitant pituitary gland tumor was identified in most rats with mammary gland fibroadenoma (21/28 [75%]) and other types of mammary gland tumors (10/17 [59%]). Fourteen of 35 (40%) rats with mammary gland fibroadenoma had concomitant reproductive tract abnormalities. CONCLUSION AND CLINICAL RELEVANCE Results suggested that, like other species, companion rats with SC masses should undergo a thorough diagnostic workup that includes histologic examination of the excised mass.

Original languageEnglish (US)
Pages (from-to)1170-1179
Number of pages10
JournalJournal of the American Veterinary Medical Association
Volume249
Issue number10
DOIs
StatePublished - Nov 15 2016

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Rattus norvegicus
mammary neoplasms (animal)
Human Mammary Glands
Fibroadenoma
Breast Neoplasms
rats
mammary glands
Reproductive Sterilization
Animal Hospitals
neoplasms
excision
pituitary gland
Pituitary Neoplasms
Pituitary Gland
Teaching Hospitals
carcinoma
Medical Records
surgery
Therapeutics

ASJC Scopus subject areas

  • veterinary(all)

Cite this

@article{0fe09f88c7414ec9bc623e7b396ccdb1,
title = "Description of the prevalence, histologic characteristics, concomitant abnormalities, and outcomes of mammary gland tumors in companion rats (Rattus norvegicus): 100 cases (1990–2015)",
abstract = "OBJECTIVE To describe the prevalence, histologic characteristics, concomitant abnormalities, and outcomes for various types of mammary gland tumors in companion rats (Rattus norvegicus). DESIGN Retrospective case series. ANIMALS 100 client-owned rats. PROCEDURES Medical records of companion rats that had an SC mass and were examined at a veterinary teaching hospital between 1990 and 2015 were reviewed. Information regarding the signalment, age at mass detection, reproductive sterilization status, histologic diagnosis of the SC mass, location of the initial and all subsequent SC masses, treatments administered, and clinical outcomes was extracted from each record and summarized. RESULTS 105 SC masses were initially detected in 100 rats. The most prevalent SC mass identified was mammary gland fibroadenoma (56/105 [53{\%}]), followed by mammary gland carcinoma (13/105 [12{\%}]). Overall, 26 of 105 (25{\%}) masses were malignant. Sexually intact males were more likely to have nonmammary SC tumors than sexually intact females. In rats receiving no adjunctive treatment after excision of a mammary gland fibroadenoma (n = 16), a second fibroadenoma was detected 1 to 8 months after initial excision, at a median of 4.5 months after surgery. A concomitant pituitary gland tumor was identified in most rats with mammary gland fibroadenoma (21/28 [75{\%}]) and other types of mammary gland tumors (10/17 [59{\%}]). Fourteen of 35 (40{\%}) rats with mammary gland fibroadenoma had concomitant reproductive tract abnormalities. CONCLUSION AND CLINICAL RELEVANCE Results suggested that, like other species, companion rats with SC masses should undergo a thorough diagnostic workup that includes histologic examination of the excised mass.",
author = "Claire Vergneau-Grosset and Keel, {Michael K} and Dayna Goldsmith and Kass, {Philip H} and Paul-Murphy, {Joanne R} and Michelle Hawkins",
year = "2016",
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day = "15",
doi = "10.2460/javma.249.10.1170",
language = "English (US)",
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pages = "1170--1179",
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T1 - Description of the prevalence, histologic characteristics, concomitant abnormalities, and outcomes of mammary gland tumors in companion rats (Rattus norvegicus)

T2 - 100 cases (1990–2015)

AU - Vergneau-Grosset, Claire

AU - Keel, Michael K

AU - Goldsmith, Dayna

AU - Kass, Philip H

AU - Paul-Murphy, Joanne R

AU - Hawkins, Michelle

PY - 2016/11/15

Y1 - 2016/11/15

N2 - OBJECTIVE To describe the prevalence, histologic characteristics, concomitant abnormalities, and outcomes for various types of mammary gland tumors in companion rats (Rattus norvegicus). DESIGN Retrospective case series. ANIMALS 100 client-owned rats. PROCEDURES Medical records of companion rats that had an SC mass and were examined at a veterinary teaching hospital between 1990 and 2015 were reviewed. Information regarding the signalment, age at mass detection, reproductive sterilization status, histologic diagnosis of the SC mass, location of the initial and all subsequent SC masses, treatments administered, and clinical outcomes was extracted from each record and summarized. RESULTS 105 SC masses were initially detected in 100 rats. The most prevalent SC mass identified was mammary gland fibroadenoma (56/105 [53%]), followed by mammary gland carcinoma (13/105 [12%]). Overall, 26 of 105 (25%) masses were malignant. Sexually intact males were more likely to have nonmammary SC tumors than sexually intact females. In rats receiving no adjunctive treatment after excision of a mammary gland fibroadenoma (n = 16), a second fibroadenoma was detected 1 to 8 months after initial excision, at a median of 4.5 months after surgery. A concomitant pituitary gland tumor was identified in most rats with mammary gland fibroadenoma (21/28 [75%]) and other types of mammary gland tumors (10/17 [59%]). Fourteen of 35 (40%) rats with mammary gland fibroadenoma had concomitant reproductive tract abnormalities. CONCLUSION AND CLINICAL RELEVANCE Results suggested that, like other species, companion rats with SC masses should undergo a thorough diagnostic workup that includes histologic examination of the excised mass.

AB - OBJECTIVE To describe the prevalence, histologic characteristics, concomitant abnormalities, and outcomes for various types of mammary gland tumors in companion rats (Rattus norvegicus). DESIGN Retrospective case series. ANIMALS 100 client-owned rats. PROCEDURES Medical records of companion rats that had an SC mass and were examined at a veterinary teaching hospital between 1990 and 2015 were reviewed. Information regarding the signalment, age at mass detection, reproductive sterilization status, histologic diagnosis of the SC mass, location of the initial and all subsequent SC masses, treatments administered, and clinical outcomes was extracted from each record and summarized. RESULTS 105 SC masses were initially detected in 100 rats. The most prevalent SC mass identified was mammary gland fibroadenoma (56/105 [53%]), followed by mammary gland carcinoma (13/105 [12%]). Overall, 26 of 105 (25%) masses were malignant. Sexually intact males were more likely to have nonmammary SC tumors than sexually intact females. In rats receiving no adjunctive treatment after excision of a mammary gland fibroadenoma (n = 16), a second fibroadenoma was detected 1 to 8 months after initial excision, at a median of 4.5 months after surgery. A concomitant pituitary gland tumor was identified in most rats with mammary gland fibroadenoma (21/28 [75%]) and other types of mammary gland tumors (10/17 [59%]). Fourteen of 35 (40%) rats with mammary gland fibroadenoma had concomitant reproductive tract abnormalities. CONCLUSION AND CLINICAL RELEVANCE Results suggested that, like other species, companion rats with SC masses should undergo a thorough diagnostic workup that includes histologic examination of the excised mass.

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JF - Journal of the American Veterinary Medical Association

SN - 0003-1488

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