Disgerminoma bilateral e hiperplasia endometrial cística com piometra em cadela

Acta Scientiae Veterinariae

Site: http://www.ufrgs.br/actavet/
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ISSN: 16799216
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Início Publicação: 31/12/1969
Periodicidade: Trimestral
Área de Estudo: Medicina Veterinária

Disgerminoma bilateral e hiperplasia endometrial cística com piometra em cadela

Ano: 2010 | Volume: 38 | Número: 3
Autores: Veronica Machado Rolim, Thadeu Mourão Pinto, Lucila Maria de Almeida Lopes, Luciana Sonne, Eduardo Conceição de Oliveira, Paula Rodrigues de Almeida, Carlos Afonso de Castro Beck, David Driemeier
Autor Correspondente: David Driemeier | [email protected]

Palavras-chave: tumores ovarianos, cão, disgerminoma bilateral, hiperplasia endometrial cística, piometra

Resumos Cadastrados

Resumo Inglês:

Background: Ovarian tumors are considered rare both in dogs and cats. Germ cell neoplasms correspond to approximately
15% of the cases and can be classified into dysgerminomas, teratomas and teratocarcinomas. Reports of bilateral dysgerminoma
in dogs and cats are rare. The aim of this work was to describe a case of bilateral dysgerminoma and cystic endometrial
hyperplasia with pyometra in a bitch by presenting the clinical, surgical, pathological and immunohistochemical findings.
Case: A 10-year-old female crossbred dog was presented with a history of vomiting, apathy and purulent vulvar discharge.
Physical examination revealed hyperthermia and pain was observed on abdominal palpation. Ultrasound examination revealed
cystic formation and increased echogenicity inside the uterus. The animal underwent ovariohysterectomy (OHE).
Macroscopically, the ovaries were multinodular, spherical to ovoid in shape, measuring 6 cm in diameter, and with a dark red
color; they exhibited a firm consistency and a hemorrhagic cut surface with cystic areas and foci of necrotic tissue. At
microscopic evaluation of both ovaries, the neoplasm consisted of large and polyhedral cells with amphophilic cytoplasm
which were arranged in cords separated by connective tissue. The cells exhibited an anaplastic appearance, with central nuclei,
large amounts of granular chromatin and one or more evident nucleoli. Several mitotic figures, often incomplete and with
consequent formation of multinucleated cells similar to giant cells, were observed. Immunohistochemical detection of
cytokeratin and vimentin was performed for further examination. The ovarian tumor exhibited positive staining for cytokeratin
and negative staining for vimentin.
Discussion: Most ovarian tumors are asymptomatic and many times are considered incidental findings during spaying surgeries.
On physical examination, affected animals may show palpable abdominal masses, ascites and systemic signs caused by
hormonal disturbances. The macroscopic and microscopic findings seen in this case are in accordance with those found in the
literature and confirm the diagnosis of bilateral dysgerminoma and cystic endometrial hyperplasia-pyometra. Dysgerminoma
should be differentiated from other neoplasias as lymphosarcoma, solid adenocarcinoma, solid granulosa cell tumor, theca cell
tumor and teratoma. Diagnosis is performed by histopathological analysis. Immunohistochemistry can be performed to
identify the origin of tumoral cells in order to assist the differential diagnosis for other neoplasias. Even though the
immunohistochemical result can be positive for cytokeratin, this is not considered usual for dysgerminomas. The positive
result for cytokeratin is related to the anaplastic characteristic of the tumor. Most cases of dysgerminomas are described in older
dogs and cats, yet it can develop in younger animals. Dysgerminoma is a tumor that is typically unilateral and is hardly ever
found in both ovaries. The rarity with which this neoplasia is observed in bitches can be related to the premature age at which
OHE is performed.