Comparison of immunohistochemical profiles of ovarian germ cells in dysgerminomas of a captive maned wolf and domestic dogs

Abstract

We characterized the immunohistochemical expression profiles of dysgerminomas from a 16-y-old maned wolf and 13 domestic dogs using the following biomarkers: Sal-like protein 4 (SALL4), octamer-binding transcription factor 3/4 (OCT3/4), placental alkaline phosphatase (PLAP), c-kit, and vimentin. The maned wolf had nonspecific and long-standing clinical signs of lethargy, anorexia, and weight loss, and was euthanized because of poor prognosis. At autopsy, the left ovary was effaced by a 12 × 8 × 6 cm mass, comprised of anaplastic cells with a mitotic count of 20 mitoses in 10 high power fields. Dysgerminomas from 7 of 13 domestic dogs had nuclear expression of SALL4. Dysgerminomas from the maned wolf and 2 domestic dogs had both nuclear and cytoplasmic expression of SALL4. Cytoplasmic expression of PLAP and OCT3/4 was present in dysgerminomas from the maned wolf and 3 (PLAP) or 4 (OCT3/4) domestic dogs. All dysgerminomas expressed vimentin. Membranous c-kit expression was rare in the dysgerminoma from the maned wolf, and variable in dysgerminomas from 4 domestic dogs. A dysgerminoma from a domestic dog had cytoplasmic expression of c-kit. SALL4 is a useful marker to confirm germ cell origin of dysgerminoma in canids.

Metastatic mammary tubulopapillary carcinoma in a captive black jaguar (Panthera onca)

“…Although the diagnosis of dysgerminoma was based on the histomorphological features, a thorough immunohistochemical characterization of the ovarian tumour would have been beneficial in our study. In a recent report, Sal‐like protein 4, octamer‐binding transcription factor 3/4 and placental alkaline phosphatase have been successfully used to confirm the germ cell line in cases of dysgerminoma from a wild canid in comparison to domestic dogs 27 . Positivity for vimentin would also be expected in dysgerminomas, in contrast to CD3, CD79a, cytokeratin, alpha‐fetoprotein, inhibin and S‐100 28 .…”

“…28 C-kit immunolabelling would have also provided some useful information regarding its prognostic and predictive value. 27 Nevertheless, despite the overall importance of this immunohistochemical profile, it is not certain whether these markers are applicable for jaguars, and none of these markers were readily available for the current report.…”

“…In a recent report, Sal-like protein 4, octamer-binding transcription factor 3/4 and placental alkaline phosphatase have been successfully used to confirm the germ cell line in cases of dysgerminoma from a wild canid in comparison to domestic dogs. 27 Positivity for vimentin would also be expected in dysgerminomas, in contrast to CD3, CD79a, cytokeratin, alpha-fetoprotein, inhibin and S-100. 28 C-kit immunolabelling would have also provided some useful information regarding its prognostic and predictive value.…”