Cutaneous metastases of a mammary carcinoma in a llama.

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and pitted on pressure; the right popliteal lymph node was approximately twice the normal size. No other abnor- malities were noted on physical examination.

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Cutaneous metastases of a mammary carcinoma in a llama Teri L. Leichner, Oliver Turner, Gary L. Mason, George M. Barrington Abstract - An 8-year-old, female llama was evaluated for nonhealing, ulcerative, cutaneous lesions, which also involved the mammary gland. Biopsies of the lesions distant from and within the mammary gland area revealed an aggressive carcinoma. The tumor was confirmed at necropsy to be a mammary gland adenocarcinoma with cutaneous metastasis.

Resume - Metastases cutanees d'un carcinome mammaire chez un lama. Un lama femelle de 8 ans a ete evalue pour des lesions cutanees ulceratives qui ne guerissaient pas et qui incluaient egalement la glande mammaire. Des biopsies provenant des lesions eloignees ainsi que de la glande mammaire ont revele un carcinome agressif. La necropsie a confirme la presence d'un adenocarcinome de la glande mammaire avec metastases cutanees. (Traduit par Docteur Andre Blouin) Can Vet J 2001;42:204-206

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8-year-old,

intact female llama

(Llama glama)

tAlwas presented to the Colorado State University Veterinary Teaching Hospital (CSU-VTH) for a primary complaint of diffuse crusting and scale located along the dorsal lumbosacral area. One month earlier, the llama had been examined by the ambulatory service for dry, crusty patches of skin at the same location. At that time, recommended treatments were daily cleansing of the area with dilute povidone-iodine scrubs and application of tincture of iodine. The lesions did not resolve with the initial treatment and the llama was referred to the CSU-VTH for additional diagnostic procedures. On physical examination, an 18- X 24-cm, malodorous, ulcerated lesion was observed in the inguinal region over the mammary gland. The mammary gland was indurated. Multiple, variably sized, depressed, ulcerated, circular lesions extending along the dorsal thoracic to the sacral area were also apparent. A 3- X 5-cm lesion, located just lateral to the right ischium, was covered with

Department of Veterinary Clinical Sciences (Leichner, Barrington), Department of Pathology (Turner, Mason), College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523 USA. Address correspondence to Dr. Teri Leichner. Dr. Leichner's current address is Virginia-Maryland Regional College of Veterinary Medicine, Phase II, Duckpond Drive, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0442 USA. Reprints will not be available. 204

fragile skin that was readily excoriated (Figure IA). The proximal part of the right hind limb was edematous and pitted on pressure; the right popliteal lymph node was approximately twice the normal size. No other abnormalities were noted on physical examination. Differential diagnoses for the cutaneous lesions included severe bacterial pyoderma, pemphigus, vasculitis, cutaneous dermatophilosis, and cutaneous neoplasia. Differential diagnoses for the mammary gland included the aforementioned differentials plus chronic mastitis and primary mammary neoplasia. A complete blood cell count (CBC), serum biochemical analysis, and thoraco- and abdominocentesis were performed. The CBC revealed mild hyperfibrinogenemia (14.75 pmol/L; reference range, 2.95 to 11.7 pmol/L). Serum biochemical analysis revealed hypoglycemia (4.28 mmol/L; reference range, 5.0 to 7.78 mmol/L), hypoproteinemia (49 g/L; reference range, 55 to 70 g/L), hypoalbuminemia (26 g/L; reference range, 35 to 44 g/L), and hypokalemia (4.0 mmol/L; reference range, 4.3 to 5.6 mmol/L). These changes were consistent with a partially anorectic animal with an inflammatory and protein-losing disease. Abdominocentesis and thoracocentesis yielded hazy, pale yellow fluid with a total protein of 23 g/L and 21 g/L, and 500 cells/pL and 400 cells/pL, respectively. Cytological evaluation of the abdominal fluid revealed many large mononuclear and fewer multinucleate cells that displayed marked anisocytosis and anisokaryosis. These cells had a deeply basophilic cytoplasm and single to multiple nuclei with large, irregular nucleoli. Nuclear molding and epithelial junctions were noted between some of the cells, and a few of the cells had large, clear cytoplasmic vacuoles. Mitotic figures were present in Can Vct J Volume 42, March 2001

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1 e WAX 1-l Figure 1. A) Cutaneous lesion, right ischium. Focal ulcerative dermatitis typical of all cutaneous lesions. B) Cutaneous lesion. Note extensive hypodermal invasion by multilobulated, densely cellular mass; hematoxylin and eosin stain; bar = 1 mm. C) Mammary gland. Note pleomorphic cellular population with marked anisocytosis and anisokaryosis; hematoxylin and eosin stain; bar = 1 mm. D) Mammary gland, longitudinal section. Diffuse infiltration by carcinoma. qo

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moderate numbers. The morphology of the cells obtained from the thoracic cavity were similar. These findings were consistent with anaplastic carcinoma. The llama was anesthetized with ketamine hydrochloride (4.4 mg/kg body weight [BW], IM), xylazine hydrochloride (0.4 mg/kg BW, IM), and butorphenol (0.04 mg/kg BW, IM). Nasal oxygen insufflation at 4 L/min was provided. Multiple punch biopsies (5 mm diameter) were obtained from the skin and tissue surrounding and including the mammary gland and dorsal lumbosacral areas. All biopsies were submitted for bacteriologic culture and histopathologic examination. No aerobes were isolated. Histopathologic findings were similar at all sites and revealed a highly anaplastic, infiltrative mass that frequently replaced large areas of normal dermal and hypodermal tissue (Figure 1B). Some sections were ulcerated and coated by an adherent serocellular crust. The mass was organized as lobules arranged into sublobules of varying size composed of irregular packets and cords of cells that, rarely, formed crude acini. The entire tissue was dissected by a dense fibrous stroma. Cells were irregular in outline, usually round to oval, and from 10 to 200 pm in diameter. Prominent nucleoli, bizarre multinucleate giant cells, and abnormal mitotic figures were present (Figure IC). Can Vet J Volume 42, March 2001

A diagnosis of anaplastic mammary carcinoma was made. Thoracic and abdominal radiographs were taken in an attempt to document the extent of the neoplastic process. Thoracic radiographs revealed a diffuse, miliary nodular pattern throughout all lung fields consistent with pulmonary metastatic disease. Other differential diagnoses included fungal pneumonia or lymphoma. Abdominal radiographs appeared normal. Because of the evidence of widespread metastasis and poor prognosis for survival, euthanasia was elected. At necropsy, no normal mammary tissue could be seen. There are normally 4 teats; however only 2 small teats were present, 1 in each of the cranial quadrants. The normal anatomic separation of the mammary gland into 8 compartments was not apparent; instead, the entire gland was replaced by a firm, tan mass (Figure 1D). This mass extended 10 cm craniad in a subcutaneous plane from the normal cranioventral limit of the mammary gland. The right inguinal, prefemoral, and popliteal lymph nodes were enlarged to approximately twice the normal size. On the cut surface, all affected sites had diffuse infiltration by tissue grossly similar to that in the mammary gland. There was extensive edema within the subcutaneous fascia of the proximal part of the 205

right hind leg. Approximately 3 L of clear, pale strawcolored fluid with fibrin strands was present in both the pleural and peritoneal cavities. There were multifocal to coalescing pale, tan, firm, 0.5- tol.0-mm nodules throughout all lung lobes. Mediastinal and bronchial lymph nodes were enlarged to approximately twice the normal size and were infiltrated by the same abnormal tissue. Multifocal to coalescing 0.5- to 2.0-cm diameter, raised, pale, tan, fibrous nodules were also present on the pleural surface of the intercostal muscles, colonic serosa, peritoneal surface of the dorsum of the pelvic inlet, omentum, mesentery, and capsular surface of the liver. Results of the histologic examination of tissues collected at necropsy were similar to those from earlier biopsies and confirmed that the neoplasm originated from the mammary gland. Metastasis was confirmed in all abnormal tissues seen at gross examination with, in addition, microscopic metastases to adrenal glands. Strongly positive immunohistochemical staining within mammary tissue and skin lesions for the intracytoplasmic intermediate filament, cytokeratin, and negative staining for vimentin, confirmed that the tumor was of epithelial origin (NEXES automated processor with anti-pankeratin (mouse IgG) and anti-vimentin (mouse IgG) antibodies; Ventana Medical Systems, Tucson, Arizona, USA). Transmission electron microscopy of mammary tissue was also performed. Tissues were diced into 1-mm cubes and fixed by immersion in 2.5% glutaraldehyde. These were then post fixed in osmium tetroxide, dehydrated in a graded ethanol series, cleared in propylene oxide, and embedded in Polarbed 812. Thin sections were stained with toluidine blue for orientation. Ultrathin sections were stained with uranyl acetate and lead citrate. Neoplastic cells had irregular cell borders with elaboration of microvillus-like surface projections, dilated mitochondria, desmosomes, and dense bundles of intermediate filaments. These findings confirmed that their origin was epithelial. Immunohistochemical staining for estrogen receptors (Estrogen receptor Ab- 13 (clone TE 11 .5d1 1); Lab Vision Corp-Neomarkers, Fremont, California, USA) was performed and revealed mild to moderate mixed positive cytoplasmic and nuclear staining in approximately 30% of the neoplastic cells. Staining in human mammary adenocarcinoma and normal alpaca mammary tissues with the same antibody was nuclear and cytoplasmic, respectively. A few crude acini were observed in all sections of tumor examined, suggesting adenocarcinoma; however, the predominant pattern of tumor growth was that of a solid carcinoma. The final diagnosis was a scirrhous anaplastic mammary carcinoma with extensive multisystem metastasis. Mammary epithelial neoplasias have been described in horses, goats, swine, cats, dogs, buffalo, rodents, and llamas (1-2). Common sites for metastasis of mammary neoplasia in mammalian species include regional lymph nodes, liver, lungs, pleura, spleen, and eye. In cats, even with extensive surgical removal, tumor size is directly related to disease-free time but not to survival (3,4). In this llama, the extent of the metastasis precluded any attempts at therapy. Reports of neoplasia in New World camelids are uncommon (2,5). Mammary adenocarcinoma is only 206

mentioned briefly; it was a mammary tumor of ductal origin (2). Radical mastectomy was performed; however, 1 y later the tumor recurred in the mammary region. At necropsy, metastasis to the sublumbar lymph nodes was observed. There are significant differences in the nature of the tumor described in this earlier report and the one reported here. To the best of our knowledge, such a locally aggressive, ulcerative, and highly metastatic mammary adenocarcinoma has not been described previously in a llama. The pathogenesis of adenocarcinomas is unknown for llamas, but estrogens and progesterones may influence tumor growth and progression. Documentation of estrogen and progesterone receptors in human breast cancer (6) and in canine mammary neoplasms (7,8) supports hormonal effects, while only progesterone receptors have been identified in cats (9). A B-type RNA virus is often associated with mammary neoplasia in mice (1). The degree of positive nuclear staining was interesting, but no conclusions can be drawn from the evaluation of this single case. To our knowledge, cutaneous metastasis of a primary mammary gland adenocarcinoma has not been reported in the llama. Cutaneous metastasis of a mammary adenocarcinoma, representing possibly local lymphatic extension of the tumor, has been reported previously in a cat, where it resembled eosinophilic plaques (10). Occlusion of lymphatic vessels with subsequent retrograde cutaneous relocation of tumor cells may play a role in the development of these lesions. Mammary adenocarcinomas are usually locally invasive early, but rapidly metastasize to other areas of the body. Even with aggressive therapy, the prognosis for affected animals is guarded at best. cv,

References 1. Theilen GH, Madewell BR. Tumors of the mammary gland. In: Theilen GH, Madewell BR, eds. Veterinary Cancer Medicine, 1979:192-203. 2. Smith JA. Noninfectious, metabolic, toxic and neoplastic diseases of camelids. In: Johnson LW, ed. Vet Clin North Am Food Anim Pract 1989:138-141. 3. Hahn KA, Adams WH. Feline mammary neoplasia: biological behavior, diagnosis, and treatment alternatives. Feline Pract 1997;25(2):5-1 1. 4. Castagnaro M, Casalone C, Bozzetta E, De Maria R, Biolatti B, Caramelli M. Tumour grading and the one-year post surgical prognosis in feline mammary carcinomas. J Comp Pathol 1998;1 19:263-275. 5. Rogers K, Barrington GM, Parish SM. Squamous cell carcinoma originating from a cutaneous scar in a llama. Can Vet J 1997;38: 1-2. 6. McGuire WL. An update on estrogen and progesterone receptors for primary and advanced breast cancer. In: lacobelli S, King RJB, Linder HR, Lippman ME, eds. Hormones and Cancer (Progress Cancer Research) 1980; 14:337-344. 7. Monson KR, Malbica JO, Hubben K. Determination of estrogen receptors in canine mammary tumors. Am J Vet Res 1977;38: 1937-1939. 8. Nelson LW, Carlton WW, Weikel JH. Canine mammary neoplasms and progestogens. J Am Med Assoc 1972;219:1601-1606. 9. Johnston SD, Hayden DW, Kiang DT, Handschin B, Johnson KH. Progesterone receptors in feline mammary adenocarcinomas. Am J Vet Res 1984;45:379-382. 10. White SD, Carpenter JL, Rappaport J, Swartout M. Cutaneous metastases of a mammary adenocarcinoma resembling eosinophilic plaques in a cat. Feline Pract 1985;15:27-29.

Can Vet J Volume 42, March 2001

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