Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Case Reports
. 2025 May 30:47:e001725.
doi: 10.29374/2527-2179.bjvm001725. eCollection 2025.

Pleomorphic lobular carcinoma in a cat: Clinical, histopathological, and immunohistochemical characterization

Júlia Gabriela Wronski  1 , Maíra Meira Nunes  1 , Érica Almeida Viscone  2 , Evelyn Ane Oliveira  1 , Mariana da Silva Figueiredo  3 , Geovanni Dantas Cassali  4 , Karen Yumi Ribeiro Nakagaki  1
Affiliations
Case Reports

Pleomorphic lobular carcinoma in a cat: Clinical, histopathological, and immunohistochemical characterization

Júlia Gabriela Wronski et al. Braz J Vet Med. .

Abstract
in English, Portuguese

Mammary carcinomas in cats are highly aggressive neoplasms, often with the development of metastasis. Pleomorphic lobular carcinoma, on the other hand, is an invasive carcinoma with aggressive behavior, rarely diagnosed in humans and dogs. This report describes a case of pleomorphic lobular carcinoma in cats. The histopathological and immunohistochemical features of the neoplasm in this species were characterized. The neoplasm was diagnosed in a 10-year-old cat, with regional lymph node involvement at the time of diagnosis, but without systemic signs based on imaging tests performed prior to mastectomy. However, respiratory clinical signs developed approximately 40 days after surgery, accompanied by neoplastic pleural effusion, and the patient was euthanized due to the onset of neurological signs and poor prognosis. Although uncommon, pleomorphic lobular carcinoma is a neoplasm that can affect cats, and given its poor prognosis, it is important for oncologists and pathologists to be familiar with this entity.

Carcinomas mamários em gatos são neoplasias altamente agressivas, frequentemente associadas ao desenvolvimento de metástases. O carcinoma lobular pleomórfico, por sua vez, é um carcinoma invasivo de comportamento agressivo, raramente diagnosticado em humanos e cães. Este relato descreve um caso de carcinoma lobular pleomórfico em um gato. As características histopatológicas e imuno-histoquímicas da neoplasia nesta espécie foram caracterizadas. A neoplasia foi diagnosticada em uma gata de 10 anos, com envolvimento de linfonodos regionais no momento do diagnóstico, mas sem sinais sistêmicos evidentes nos exames de imagem realizados antes da mastectomia. No entanto, sinais clínicos respiratórios surgiram cerca de 40 dias após a cirurgia, acompanhados de derrame pleural neoplásico, e a paciente foi eutanasiada devido ao início de sinais neurológicos e prognóstico reservado. Embora incomum, o carcinoma lobular pleomórfico é uma neoplasia que pode acometer gatos e, dado seu prognóstico desfavorável, é importante que oncologistas e patologistas estejam familiarizados com essa entidade.

Keywords: breast carcinoma; invasive lobular carcinoma; pleural effusion; stage IV.

PubMed Disclaimer

Conflict of interest statement

Conflicts of interest: No conflict of interest.

Figures

Figure 1
Figure 1. Histological features of lobular pleomorphic carcinoma in a cat. A. In the mammary gland and invading the dermis, two neoplastic proliferations were observed: tubulopapillary carcinoma (thick arrow) and lobular pleomorphic carcinoma (thin arrow), with invasive areas in the superficial dermis. B. The lobular pleomorphic carcinoma also exhibited in situ areas (arrow), primarily within the mammary gland, where cells were loosely arranged inside the mammary ducts. C and D. In the invasive areas, cells were arranged in an Indian file pattern or dispersed within the stroma, exhibiting marked pleomorphism, with large nuclei, prominent nucleoli, frequent karyomegaly, bizarre nuclei, and multinucleation.
Figure 2
Figure 2. Immunohistochemical features of lobular pleomorphic carcinoma in a cat. Cells were strongly positive for the progesterone receptor (A) and scored 3 for cyclooxygenase 2 (B). For E-cadherin, the neoplastic cells of the lobular pleomorphic carcinoma were negative (arrow), while the cells of the tubulopapillary carcinoma were positive (asterisk). The Ki67 marker showed positive nuclear staining in approximately 90% of the neoplastic cells (D).
See this image and copyright information in PMC

References

    1. Al-Baimani K., Bazzarelli A., Clemons M., Robertson S. J., Addison C., Arnaout A. Invasive pleomorphic lobular carcinoma of the breast: Pathologic, clinical, and therapeutic considerations. Clinical Breast Cancer. 2015;15(6):421–425. doi: 10.1016/j.clbc.2015.06.010. - DOI - PubMed
    1. Araújo M. R., Campos L. C., Ferreira E., Cassali G. D. Quantitation of the regional lymph node metastatic burden and prognosis in malignant mammary tumors of dogs. Journal of Veterinary Internal Medicine. 2015;29(5):1360–1367. doi: 10.1111/jvim.13576. - DOI - PMC - PubMed
    1. Cassali G. D., Gärtner F., Schmitt F. C. Pleomorphic lobular carcinoma of the canine mammary gland: Histopathologic and immunohistochemical features. Arquivo Brasileiro de Medicina Veterinária e Zootecnia. 2002;54:592–594. doi: 10.1590/S0102-09352002000600006. - DOI
    1. Cassali G., Jark P., Gamba C., Damasceno K., Estrela-Lima A., Nardi A., Ferreira E., Horta R., Firmo B., Sueiro F., Rodrigues L., Nakagaki K. Consensus regarding the diagnosis, prognosis and treatment of canine and feline mammary tumors-2019. Brazilian Journal of Veterinary Pathology. 2020;13(3):555–574. doi: 10.24070/bjvp.1983-0246.v13i3p555-574. - DOI
    1. Cassali G. D., Nakagaki K. Y. R. Patologia mamária canina e felina: Do diagnóstico ao tratamento. 2nd. Editora MedVet; 2023.

Publication types

LinkOut - more resources