Papillary ductal adenocarcinoma in the mammary glands of two horses

Abstract

Mammary gland neoplasms in horses are uncommon and may initially be confused with mastitis. Masses from the mammary glands of two horses with chronic discharges were examined by cytology and histopathology. Both masses were diagnosed as papillary ductal adenocarcinomas with extensive intraductal and intralobular involvement and only focal infiltration of the adjacent stroma. Complementary immunohistochemical studies were made of both fresh and formalin-fixed tumour tissue, and attempts were made to assess the steroid receptor status of fresh tissue biochemically to assess the possibility of hormonal treatment as an adjunct to surgery. The results of these tests for oestrogen and progesterone receptors were negative.

Invasive micropapillary carcinoma of the mammary glands in a mare

“…This report described the clinical, pathological, and immunophenotypical characteristics of invasive micropapillary carcinoma of the mammary glands of an intact mare. Equine mammary carcinomas consist of solid carcinomas (Schmahl 1972;Acland and Gillette 1982;Munson 1987), papillary ductal adenocarcinomas (Foreman 1990;Reppas et al 1996;Prendergast et al 1999), and ductal carcinomas (Hirayama et al 2003). Histopathological findings in this report correspond to the IMC in humans, dogs, and cats.…”

“…Neoplasms of the mammary glands are common in carnivores but are very uncommon in herbivores (Moulton 1990). In horses, there are only a few reports of mammary neoplasms in the last 30 years (Schmahl 1972;Acland and Gillette 1982;Munson 1987;Foreman et al 1990;Seahorn 1992;Reppas et al 1996;Kato et al 1998;Prendergast et al 1999;Hirayama et al 2003;Brito et al 2008). Invasive micropapillary carcinoma (IMC) of the breast is an aggressive and distinctive variant of human infiltrative ductal carcinoma, which presents lymph tropism and frequently spreads to the lymph nodes (Luna-moreé t al.…”

Mammary adenocarcinoma in a mare

“…Contrary to what occurs in dogs (HEIDRICH & RENK, 1967) and cats (REPPAS et al, 1996;KATO et al, 1998;MACEACHERN et al, 2001;HIRAYAMA et al, 2003), mammary neoplasms are uncommon in herbivores (THEILEN & MADEWELL, 1987;PRENDERGAST et al, 1999;MISDORP, 2002;HIRAYAMA et al, 2003). In equines, rare descriptions of mammary neoplasms are found in animals above 12 years of age (PRENDERGAST et al, 1999).…”

“…In 29 cases of mammary tumors in mares found in the literature (SCHMAHAL, 1972;THEILEN & MADEWELL, 1987;SEAHORN et al, 1992;PRENDERGAST et al, 1999;HIRAYAMA et al, 2003), and 28 cases of acute mastitis (MCCUE & WILSON, 1989). Initially, the process can be confused with mastitis (REPPAS et al, 1996). Pain was found in 8 and 15 animals, respectively.…”

Nasal Adenocarcinoma in a Horse with Metastasis to Lung, Liver, and Bone and Review of Metastasis in Nine Horses with Sinonasal Tumors

“…Adenocarcinomas in the horse are uncommon but have been reported to occur in a variety of locations including lung, intestine, kidney, skin, lacrimal gland, testes, ovary, mammary tissue, sinuses, and nasal passages [1][2][3][4][5][6][7]. Adenocarcinomas of nasal and paranasal sinus origin are rare tumors affecting equids but can cause significant morbidity.…”