Splenic metastasis in a bitch affected by an ovarian dysgerminoma - a case report

Dysgerminomas are infrequent neoplasms resulting from undifferentiated germinal cells, mainly observed in the bitch. Our case describes for the first time a dysgerminoma related splenic metastasis in a bitch. A 14-year-old crossbred bitch was admitted at our facility with a 3-month history of irregular oestrous cycle, vulvar swelling, haemorrhagic vaginal discharge, lethargy and anorexia. Cytological examination showed the presence of superficial epithelial cells of the vaginal mucosa with a high degree of cornification. Vaginoscopy showed the typical pale and crenulated mucosal folds (oestrus). Haematological analysis indicated moderate anaemia and leukocytosis, and increased level of oestrogen. Ultrasound examination showed a mass located caudally to the kidney in the region of the right ovary. Abdominal and thoracic radiographs confirmed the findings and did not reveal metastases. Suspecting an ovarian tumour, we decided to perform a complete ovariohysterectomy. Once located, the right ovary presented an increased volume, irregular shape and reddish colour. Samples collected during the procedure were stained with haematoxylin and eosin and observed under optical microscope. The cells were characterized by a scant cytoplasm, a large vesicle type nucleus with coarsely granular chromatin and distinct cell borders. The neoplastic cells were remarkably similar to those of a testicular seminoma, allowing for the diagnosis of ovarian dysgerminoma. Two years after the ovariohysterectomy, the owner reported history of increased volume of the abdomen and lethargy. A second surgery was performed during which an irregular splenic mass was found. The morphological diagnosis was “splenic metastasis of dysgerminoma”. To the authors' knowledge, dysgerminoma related splenic metastasis was never described in the bitch before.

A retrospective pathology study of two Neotropical deer species (1995-2015), Brazil: Marsh deer (Blastocerus dichotomus) and brown brocket deer (Mazama gouazoubira)

This retrospective study describes the biological and epidemiological aspects, gross and microscopical findings, and most likely causes of death (CD) in two species of Neotropical deer in Brazil. The animals were collected between 1995 and 2015 and represented 75 marsh deer (MD) and 136 brown brocket deer (BBD). Summarized, pneumonia was diagnosed microscopically in 48 MD and 52 BBD; 76 deer suffered trauma, involving dog attack (14 BBD) and vehicle-collision (14 BBD). Pulmonary edema (50 MD; 55 BBD) and congestion (57 MD; 78 BBD) were the most common findings for both species. Additionally, we diagnosed ruminal and myocardial mycosis in MD and BBD, respectively; ovarian dysgerminoma and pancreatic trematodiasis in BBD; and lesions suggestive of malignant catarrhal fever and orbiviral hemorrhagic disease in both species. The main CD in MD was: respiratory (41/75), alimentary, nutritional, trauma and euthanasia (3/75 each). Correspondingly, in BBD were: trauma (34/131), respiratory (30/131) and euthanasia (9/131). Respiratory disease was often defined by pulmonary edema and pneumonia. We provide evidence that respiratory disease, mainly pneumonia, is a critical pathological process in these Neotropical deer species. Although no etiological agents were identified, there is evidence of bacterial and viral involvement. Our results show trauma, mainly anthropogenic, as a common ailment in BBD. We propose to prioritize respiratory disease in future research focused on South American deer health aspects. We believe anthropogenic trauma may be a primary threat for populations of BBD.

Expression of protein gene product 9.5 and Sal-like protein 4 in canine seminomas

The aim of the present study was to characterize canine classical seminoma (SE) and spermatocytic seminoma (SS) by immunohistochemical expression of gonocytic and spermatogonial cellular markers (c-Kit, placental alkaline phosphatase [PLAP], protein gene product 9.5 [PGP9.5] and Sal-like protein 4 [Sall4]) and histochemically by the periodic acid-Schiff (PAS) reaction. Twenty-five cases of SE and 23 cases of SS were investigated. Two cases of dysgerminoma were also examined. c-Kit was expressed on the cell membrane of 13 of 25 cases of SE (52%) and four of 23 cases of SS (16%). This marker was not expressed in dysgerminoma. PLAP immunoreactivity was observed in the cytoplasm of neoplastic cells of six of 25 cases of SE (24%). PLAP was not expressed in cases of SS and dysgerminoma. All samples of SE, SS and dysgerminoma showed cytoplasmic expression of PGP9.5 and nuclear immunoreactivity for Sall4. There was fine granular cytoplasmic PAS staining in neoplastic cells in five of 25 cases of SE (20%), while all samples of SS and dysgerminoma cases were PAS negative. These findings suggest that it is not possible to differentiate canine SE and SS using these markers. This may be because canine SS may be derived from spermatogonia that can differentiate to spermatocytes and also because cases of canine SE might consist of neoplastic cells that have lost their gonocytic nature. This study was the first to show positive immunoreactivity for Sall4 in canine seminomas and dysgerminomas and expression of PGP9.5 in canine dysgerminomas.

Dysgerminoma in an eastern rosella (Platycercus eximius eximius)

This report describes a case of dysgerminoma in a 21-year-old eastern rosella (Platycercus eximius eximius) that presented with dyspnea and a severely distended coelom. The bird was euthanatized, and a large, left-sided coelomic mass was identified. Microscopically, the mass was composed of sheets and nests of round to polygonal neoplastic cells with lacy cytoplasm. The neoplastic cells were weakly positive for vimentin and c-kit but negative for pancytokeratin, AE1, and inhibin. On the basis of the histomorphology and immunoreactivity, the neoplasm was determined to be a dysgerminoma. The variability of histologic appearance and immunohistochemical staining of dysgerminomas in humans compared with veterinary species is discussed.