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Journal of Veterinary Diagnostic Investigation Vol. 21 Issue 1, 153-155
Copyright © 2009 by the American Association of Veterinary Laboratory Diagnosticians
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Case Reports

A simple ductal mammary papilloma in a male maned wolf (Chrysocyon brachyurus)

Geovanni D. Cassali1, Angélica C. Bertagnolli, Enio Ferreira and Marcelo C.C. Malta

Correspondence: 1Corresponding Author: Geovanni D. Cassali, Laboratory of Comparative Pathology, Department of General Pathology, Institute of Biological Sciences, Federal University of Minas Gerais, Antonio Carlos Avenue 6627, CEP: 31270-901, Belo Horizonte, Minas Gerais, Brazil. cassalig{at}icb.ufmg.br


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A 1-cm-diameter nodule was identified in the left inguinal mammary gland of a 9-year-old male maned wolf (Chrysocyon brachyurus). The mass was surgically excised and examined histologically. Microscopically, the neoplasm consisted of papillary proliferations of epithelial cells on well-defined fibrovascular stalks. A myoepithelial layer was located between the single layer of epithelial cells and the fibrovascular stalk. This histologic appearance was compatible with a diagnosis of simple ductal mammary papilloma. Immunohistochemical staining was positive for p63, cytokeratins AE1/AE3, and estrogen receptors. The clinical and histologic observations in the present case indicate that male maned wolves may develop mammary tumors that are similar to those observed in domestic dogs and humans.

Key Words: Chrysocyon brachyurus • ductal mammary papilloma • male maned wolves

Mammary tumors are the most frequent neoplasms in female dogs and account for about 50% of all histologically diagnosed tumors in dogs. The incidence of mammary neoplasms is increased in older and intact animals.2,17 In male dogs, mammary neoplasms are rare and generally are observed in animals of advanced age.19,21 Information regarding the frequency of mammary tumors in free-ranging carnivores is limited. Mammary tumors have been reported previously in a red fox (Vulpes vulpes),11 black-footed ferrets (Mustela nigripes),3,12 and a European pine marten (Martes martes).25

The present study describes the histological and immunohistochemical characteristics of a simple ductal mammary papilloma in a male maned wolf (Chrysocyon brachyurus). The maned wolf is a member of the family Canidae and lives in the South American grasslands and scrub forests of Brazil, northern Argentina, Paraguay, eastern Bolivia, and southeastern Peru. The maned wolf is historically one of the most typical carnivorous species found in central and southern Brazil but is currently listed on the official Brazilian list of species threatened with extinction.14

A 1.0-cm-diameter nodule was identified in the left inguinal mammary gland of a 9-year-old male maned wolf born at the Zoo-Botanic Foundation of Belo Horizonte, Minas Gerais, Brazil. The mass was surgically excised, and samples were collected for histopathology and immunohistochemistry. The tissues were fixed in 10% neutral buffered formalin solution, trimmed, processed routinely, and embedded in paraffin. The paraffin blocks were sectioned at 3 µm and stained with hematoxylin and eosin for histologic evaluation.

Microscopically, the nodule was composed of an orderly proliferation of epithelial cells characterized by papillary arrangements on well-defined fibrovascular stalks. A layer of myoepithelial cells was observed between the layer of epithelial cells and the fibrovascular stalk. The microscopic appearance of the lesion was compatible with a simple ductal mammary papilloma (Fig. 1). The histologic diagnosis of simple ductal papilloma subsequently was confirmed by 2 additional pathologists following diagnostic criteria for mammary tumors.15


Figure 01
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  		Figure 1 Simple ductal mammary papilloma from a male maned wolf showing papillary proliferation of epithelial cells on well-defined fibrovascular stalks. Hematoxylin and eosin. Bar = 100 µm.

 
Immunohistochemistry was performed on replicate tissue sections using monoclonal antibodies against estrogen receptor (1:150 dilution; NCL-LH2a), p63 (1:100 dilution; 4A4b), and cytokeratins (CK) AE1/AE3 (1:100 dilution; CK AE1/AE3a). The reactivity of the antibodies in canine mammary cells was reported previously.7,19 The sites of primary antibody binding were identified by the streptavidin–biotin–peroxidase complex methodc using diaminobenzidinec as the chromogen.

Negative controls consisted of replacing the primary antibody with phosphate buffered saline. The adjacent normal mammary tissue was used as an internal control in each test. Normal mammary gland samples obtained from domestic female dogs were used as positive controls for p63 and CK AE1/AE3 immunoreactivity. One complex adenoma with proven immunoreactivity for estrogen receptors from another female dog was used as a positive control for this immunostaining procedure. The number of cells immunoreactive for p63 and CK AE1/AE3 was scored semiquantitatively as follows: 0 = no stained cells; + = <10% positive cells; ++ = 10–50% positive cells; and +++ = >50% positive cells. The number of estrogen receptor–positive cells was determined as the percentage of stained cells: – = no staining or less than 5% of nuclei stained; + = 5–19% of nuclei stained; ++ = 20–59% of nuclei stained; and +++ = ≥60% of nuclei stained.

In the normal canine mammary gland (positive control), the alveolar and ductal epithelial cells were positive for CK AE1/AE3 and estrogen receptor, and negative for p63. The nuclei of myoepithelial cells uniformly distributed around the ductal and alveolar structures stained positively for p63 (+++) and CK AE1/AE3 (+).

In the simple ductal papilloma from the maned wolf of this report, estrogen receptor immunoreactivity was detected in the nuclei of a small number of epithelial cells (+). Most luminal epithelial and myoepithelial cells had cytoplasmic staining for CK AE1/AE3 (+++; Fig. 2). Immunostaining for p63 (+++) was restricted to the nuclei of myoepithelial cells located between the luminal epithelium and basement membrane. These cells were also positive for CK AE1/AE3 (+; Figs. 2, 3).


Figure 02
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  		Figure 2 Immunohistochemical reactivity for cytokeratins AE1/AE3 in the epithelial cells of a mammary simple ductal papilloma from a male maned wolf. Bar = 50 µm.

 

Figure 03
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  		Figure 3 Immunohistochemical reactivity for p63 in the myoepithelial cells of a mammary simple ductal papilloma in a male maned wolf. Bar = 50 µm.

 
Despite the high incidence of mammary tumors in female dogs, these neoplasms occasionally have been reported in male dogs.17,23 The life span of the maned wolf is 13 years; therefore, the present tumor was diagnosed in an older animal as has been reported for mammary neoplasms in male domestic dogs.23 Because wild canids are not examined routinely, it is possible that the frequency of mammary tumors might be higher than indicated in reports of peer-reviewed literature. The lack of detection or absence of registration of neoplasms may contribute to the scarcity of information about the occurrence of mammary tumors in wild canids.

The simple ductal papilloma in the male maned wolf of this report is a benign mammary tumor that usually is diagnosed in female dogs.15 In humans, all histologic types of mammary neoplasia observed in women also have been described or reported in men. However, mammary tumors in men are predominantly ductal in origin because the male breast normally does not contain lobules. Furthermore, papillary growth is common in male breast carcinomas.22

Immunohistochemical staining revealed immunoreactivity of neoplastic epithelial luminal cells for CK AE1/AE3, confirming the presence of epithelial cells in the neoplasm. The CK AE1/AE3 antibody identifies the presence of cytokeratins and has been used as a marker of epithelial cells in mammary tumors and other neoplasms.9

In domestic dogs, the occurrence of complex tumors with luminal epithelial cells and myoepithelial cells is common.15 The p63 antibody is a specific and sensitive marker to identify myoepithelial cells.1,7 The absence of p63 immunoreactivity in the interstitial myoepithelial cells confirms that the mammary neoplasm in the maned wolf in the current study is a simple as opposed to a complex neoplasm. Several myoepithelial markers such as calponin, smooth muscle actin, S-100, and cluster of differentiation (CD) 10 can also be used as myoepithelial cell markers.4,26 The advantages of p63 include its nuclear staining and the lack of cross-reactivity with stromal myofibroblasts.1 Additionally, the observation of p63 reactivity in myoepithelial cells at the epithelial–stromal junction demonstrated the integrity of the myoepithelium and confirmed the simple papillary nature of this ductal papilloma. The microscopic distinction between papillary adenoma and papillary carcinoma is critical to proper diagnosis. Consensus exists that ductal papillomas retain a continuous myoepithelial layer, whereas papillary carcinomas have focal clusters of or absence of myoepithelial cells.20

Estrogen receptor immunoreactivity suggests the participation of steroid-derived hormones in the pathogenesis of mammary tumors in wild animals, as has been observed for similar neoplasms of humans and domestic dogs. Estrogen promotes neoplastic growth by stimulating epithelial proliferation through the estrogen receptor.10 In female dogs, both malignant and benign neoplasms may have estrogen receptors.5,13 In humans, studies have shown that more than 80% of breast carcinomas in men are estrogen-receptor positive,8,22 and conditions that increase the exposure to estrogen such as iatrogenic exogenous administration of estrogen, obesity, and testicular diseases increase the risk of developing breast cancer.6,24 The presence of testicular tumors also may pose a risk for the development of mammary neoplasms in dogs,16 but this was not the case in the maned wolf in the current report. However, the epidemiologic, histologic, and immunohistochemical findings in this maned wolf suggest that wild canids also may develop mammary neoplasms that are histologically and biologically similar to their counterparts in domestic dogs and humans.


   Acknowledgments
 
The authors thank the National Council of Scientific and Technological Development (CNPq; Brazil), the Brazilian Federal Agency for the Support and Evaluation of Graduate Education (CAPES), and the Research Support Foundation of the State of Minas Gerais (FAPEMIG; Brazil) for financial support.


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From the Laboratory of Comparative Pathology, Department of General Pathology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil (Cassali, Bertagnolli, Ferreira), and the Zoo-Botanic Foundation, Zoo of Belo Horizonte, Belo Horizonte, Minas Gerais, Brazil (Malta). Back

a Novocastra Laboratories Ltd., Newcastle upon Tyne, UK. Back

b NeoMarkers Inc., Fremont, CA. Back

c Dako North America Inc., Carpinteria, CA. Back


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  1. Barbareschi M., Pecciarini L., Cangi G.M., et al. 2001 p63, a p53 homologue, is a selective nuclear marker of myoepithelial cells of the human breast. Am J Surg Pathol 25 1054 1060.[Medline]
  2. Brodey R.S., Goldschmidt M.H., Roszel J.R. 1983 Canine mammary gland neoplasia. J Am Anim Hosp Assoc 19 61 63.
  3. Carpenter J.W.J., Davidson J.P., Novilla M.N., et al. 1980 Metastatic papillary cystadenocarcinoma of the mammary gland in a black-footed ferret. J Wildl Dis 16 587 592.[Medline]
  4. Dabbs D.J., Gown A.M. 1999 Distribution of calponin and smooth muscle myosin heavy chain in fine-needle aspiration biopsies of the breast. Diagn Cytopathol 20 203 207.[Medline]
  5. Donnay I., Rauis J., Devleeschouwer N., et al. 1995 Comparison of estrogen and progesterone receptor expression in normal and tumor mammary tissues from dogs. Am J Vet Res 56 1188 1194.[Medline]
  6. Ewertz M., Holmberg L., Tretli S., et al. 2001 Risk factor for male breast cancer: a case-control study from Scandinavia. Acta Oncol 40 467 471.[Medline]
  7. Gama A., Alves A., Gartner F., Schmitt F. 2003 p63: a novel myoepithelial cell marker in canine mammary tissues. Vet Pathol 40 412 420.[Medline]
  8. Giordano S.H., Cohen D.S., Buzdar A.U., et al. 2004 Breast carcinoma in men: a population-based study. Cancer 101 51 57.[Medline]
  9. Griffey S.M., Madewell B.R., Dairkee S.H., et al. 1993 Immunohistochemical reactivity for basal and luminal epithelium–specific cytokeratin antibodies within normal and neoplastic canine mammary glands. Vet Pathol 30 155 161.[Medline]
  10. Howell A. 1983 Clinical evidence for the involvement of estrogen in the development and progression of breast cancer. Proc Roy Soc Edinb B Biol Sci 95 49 57.
  11. Janovsky M., Steineck T. 1999 Adenocarcinoma of the mammary gland in a red fox from Austria. J Wildl Dis 32 392 394.
  12. Lair S., Barker I.K., Mehren K.G., Willians E.S. 2002 Epidemiology of neoplasia in captive black-footed ferrets (Mustela nigripes), 1986–1996. J Zoo Wildl Med 33 204 213.[Medline]
  13. Las Mulas M.J., Orda S.J., Millán M.Y., et al. 2004 Immunohistochemical expression of estrogen receptor ß in normal and tumoral canine mammary glands. Vet Pathol 41 269 272.[Medline]
  14. Ministry of the Environment, Brazil 2003 Normative instruction. 3, 27 May. Union Official Diary, session 1 101 88 97 In Portuguese..
  15. Misdorp W. 2002 Tumors of the mammary gland. In: Tumors in domestic animals Meuten D.J. 4th ed., 575 606 Iowa State Press Ames, IA.
  16. Misdorp W., Else W., Hellmen E., Lipscomb T. 1999 Histological classification of the mammary tumors of the dog and the cat. World Health Organization international histological of tumors of domestic animals, 2nd series, vol. VII Armed Forces Institute of Pathology, American Registry of Pathology Washington, DC.
  17. Moulton J.E., Taylor D.O.N., Dorn C.R., Andersen A.C. 1970 Canine mammary tumors. Vet Pathol 7 289 320.
  18. Munson L., Moresco A. 2007 Comparative pathology of mammary gland cancers in domestic and wild animals. Breast Dis 28 7 21.[Medline]
  19. Nieto A., Penña L., Perez-Alenza M.D., et al. 2000 Immunohistologic detection of estrogen receptor alpha in canine mammary tumors: clinical and pathologic associations and prognostic significance. Vet Pathol 37 239 247.[Medline]
  20. Page D.L., Anderson T.J. 1987 Papilloma and related lesions. In: Diagnostic histopathology of the breast 104 119 Churchill-Livingstone Edinburgh, United Kingdom.
  21. Saba C.F., Rogers K.S., Newman S.J., et al. 2007 Mammary gland tumors in male dogs. J Vet Intern Med 21 1056 1059.[Medline]
  22. Schneider R. 1970 Comparison of age, sex and incidence rates in human and canine breast cancer. Cancer 26 419 426.[Medline]
  23. Stalsberg H., Thomas D.B., Rosenblant K. 1993 Histologic types and hormone receptors in breast cancer in men: a population-based study in 282 United States men. Cancer Causes Control 4 143 151.[Medline]
  24. Thomas D.K.B., Jimenez I.M., McTiernam A., et al. 1992 Breast cancer in men: risk factors with hormonal implications. Am J Epidemiol 135 734 748.[Abstract/Free Full Text]
  25. Williams E.S., Thorne E.T., Steineck T. 1989 Spontaneous tumors of free-ranging terrestrial mammals of North America. In: Comparative aspects of tumor development Kaise H.E. 214 225 Kluwer Academic Dordrecht, The Netherlands.
  26. Yaziji H., Grow A.M., Sneige N. 2000 Detection of stromal invasion in breast cancer: the myoepithelial markers. Adv Anat Pathol 7 100 109.[Medline]




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