Mammary ductal carcinoma with comedo pattern in a rhesus macaque
A 23-year-old female rhesus macaque presented with a 2.5-cm diameter, firm, moveable, lobulated subcutaneous mass associated with a supranummary teat on the right side of the chest. This animal was a retired breeder, currently in an aging study. No exogenous hormone treatments were noted in the animal's history. Chest radiographs were within normal limits. Blood screens showed no noteworthy variations from normal. Needle aspirate cytology showed clusters of neoplastic cells. Grossly the mass was well circumscribed, firm, and homogeneously tan, with a glandular appearance. Differential diagnoses included sebaceous or mammary adenoma, carcinoma in situ, and lobular or ductular carcinoma. Histopathology was consistent with a mammary ductal carcinoma with comedo pattern. Subsequent needle aspirate cytology from an adjacent right axillary lymph node showed tumor cells with a few lymphoid cells, interpreted as lymphatic spread. Chest radiographs 2 and 6 weeks postbiopsy showed no evidence of pulmonary metastasis. After 1 year, there was no marked change on chest radiographs, but a small cluster of new nodules was palpable in the right axillary region. Histopathology of an excisional biopsy of the new nodules indicated tumor growth subjacent to regional lymph nodes. Further treatment was not performed and the animal remained clinically normal five years after the initial diagnosis. Spontaneous mammary neoplasia is a major concern in human medicine, yet it rarely has been reported to occur in nonhuman primates. This case is important in documenting an additional case of spontaneous mammary tumor development.
[Show abstract] [Hide abstract] ABSTRACT: Mammary tumors in non-human primates are rare. The aim of this paper is to report the occurrence and treatment outcomes of a female Cebus sp. (fam. Cebidae) with high-grade mammary carcinoma received at the Serviço de Atendimento de Animais Selvagens (SAAS), Universidade Estadual do Centro-Oeste. A right mammary gland nodule was identified and at radiographic examination a point of radiopacity due to gun projectile entrapped within the mammary mass was seen. After the patient stabilization, the mass was excised and submitted to histopathological examination. The diagnosis was of high-grade carcinoma, compatible with adenosquamous carcinoma. The monkey was transported to Wild Animals Treat and Receiving Center (CETAS) and introduced into a colony. More than 20 months after surgery no evidence of relapse was seen and the patient is living with the group. That suggests that the adopted therapy was effective, achieving quality of life and increased survival.
- "Estas neoplasias são bem mais frequentes em humanos e foram encontrados apenas 35 relatos em primatas não humanos. Nestes relatos os tipos histológicos encontrados foram os seguintes: adenocarcinoma, sarcoma fusocelular, tumor misto, carcinoma de células escamosas, carcinoma ductal, fibroadenoma, e fibrossarcoma (Tekeli & Ford 1980, Hubbard et al. 1984, Waggie et al. 2000, Lewis & Colgin 2005, Smith et al. 2005). Esta é a primeira descrição de um caso de neoplasia mamária em Cebus sp. "
- [Show abstract] [Hide abstract] ABSTRACT: A spontaneous mammary gland ductal carcinoma was diagnosed in a 13-year-old female captive rhesus monkey (Macaca mulatta). The expression of argyrophilic nucleolar organizer regions (AgNORs) was studied to investigate the correlation between the histologic invasiveness and cell proliferation activity assay for predicting the biologic behavior of this tumor type. The results of this study show that the AgNOR size in tumor cells reflect the degree of malignancy when compared with the pattern of peripheral blood lymphocytes of the same individual. This is the first study showing a significant AgNOR feature of a malignant breast tumor in a rhesus monkey and it longs to provide additional diagnostic tool in tumor pathology.
- [Show abstract] [Hide abstract] ABSTRACT: Here we describe a case of mammary gland ductal carcinoma in an aged rhesus macaque. Tumors were diagnosed based on routine hematoxylin and eosin staining. Invasiveness was further characterized by p63 immunohistochemistry. p63 is a p53 homolog that strongly and specifically stains nuclei of myoepithelial cells in human and canine mammary tissue. Because p63 has an affinity for the nucleus of myoepithelial cells, it is readily visible. Staining of mammary tissue from the monkey for p63 revealed that multiple foci of neoplastic cells had breached the myoepithelial cell layer surrounding ducts, suggesting the potential for local invasion of the tumor. Regional metastasis was confirmed at necropsy. To our knowledge, this is the first documented use of p63 for effectively determining the invasive nature of a mammary tumor in a nonhuman primate and the first use of p63 as an effective means of staining myoepithelial cells in a mammary ductal carcinoma in a nonhuman primate. Because nonhuman primates are important animal models for human diseases, including neoplasia, this method may prove useful for both diagnostic and research purposes.