Morphological and Immunohistochemical Characterization of Spontaneous Mammary Gland Tumors in the Guinea Pig (Cavia porcellus)

Abstract

Ten spontaneous mammary gland tumors affecting guinea pigs (GP) were analyzed histologically and immunohistochemically. Histologically, 3 were benign (2 simple adenomas and 1 benign mixed tumor) and 7 were malignant (1 simple solid carcinoma and 6 simple tubulopapillary carcinomas). Immunohistochemical data revealed the glandular immunoprofile of all the tumors and suggested their ductal origin on the basis of cytokeratin 20 expression. Interestingly, cytokeratin 7 was detected in basal/ myoepithelial cells. Further, all tumors were positive for type a estrogen and progesterone receptors, suggesting a role for steroid hormones in the development of these neoplasias in GP. This article describes the morphological and immunohistochemical features of the normal mammary gland and spontaneous mammary gland tumors in GP.

Mammary tubular carcinoma in a guinea pig (Cavia porcellus): case report

“…Common tumors in guinea pigs include bronchogenic papillary adenomas, trichofolliculomas, skin carcinomas, teratomas involving the ovary, mammary gland fibroadenomas [4], lymphoma [13], cutaneous vascular malformations [14], mammary adenocarcinoma [6], simple solid breast carcinoma, simple tubulopapillary breast carcinoma [7] and fibroblastic osteosarcoma [5]. This is, however, the first case reporting a mammary tubular carcinoma in Cavia porcellus.…”

“…Bronchogenic papillary adenoma is the most common neoplasm diagnosed in guinea pigs, followed by skin tumors and subcutaneous tumors [4], and more recently a case of fibroblastic osteosarcoma [5]. Regarding mammary neoplasms, adenocarcinomas [6], simple solid carcinomas and simple tubulopapillary carcinomas [7] have been reported.…”

Achados citológicos em neoplasia mamária em porquinho da índia (Cavia porcellus) macho: Relato de caso

“…Sua expectativa de vida é de quatro a cinco anos (Carpenter, 2010). O tumor mais comum encontrado em cobaias é o adenoma papilar broncogênico, seguido por tumores da pele e subcutâneo (Suárez-Bonnet et al, 2010). Existem poucos relatos na literatura sobre tumor mamário em porquinho da índia (Grandi et al, 2011).…”

Mammary carcinoma in a male rhesus macaque (Macaca mulatta): histopathology and immunohistochemistry of ductal carcinoma in situ

“…Cases of male mammary neoplasia have been described in domestic animals, with frequent reports in cats and dogs . In laboratory species, mammary tumors have been observed in male rats, mice, and guinea pigs . While not noted with the same regularity as in these species, there are reports of mammary hyperplastic and neoplastic lesions in different species of female non‐human primates .…”