<abstract xmlns="http://www.w3.org/1999/xhtml"><p> The aim of this study was to re-evaluate archived samples of canine soft tissue sarcomas (STSs) morphologically consistent with peripheral nerve sheath tumors (PNSTs). In each case, an immunohistochemical panel was applied, including α-SMA, calponin, desmin, S-100, GFAP, NSE and Olig2, in order to assess whether the phenotype was consistent with the tumor histological appearance. Additionally, the expression of EGFR, a marker with potential therapeutic implications in malignant PNSTs, was evaluated. Twenty-one tumors were included. Fourteen cases (66.7%) were positive for one or more muscular markers and were reclassified as perivascular tumors (PWTs). A positive labeling for S-100 was observed in one tumor (4.8%), thus classifi ed as PNST. The other 6 tumors were generically classified as poorly differentiated STSs. No unique histopathological feature was observed within the three groups. NSE and Olig2 labeling was aspecific and not useful for diagnostic purposes. GFAP was negative in all cases. Six cases (28.6%) were positive for EGFR, including the PNST. Even after the application of a wide immunohistochemical panel, distinguishing between PNSTs and PWTs remains a challenge. Finally, a subgroup of cases cannot be classified based on light microscopy alone.</p></abstract>

The aim of this study was to re-evaluate archived samples of canine soft tissue sarcomas (STSs) morphologically consistent with peripheral nerve sheath tumors (PNSTs). In each case, an immunohistochemical panel was applied, including α-SMA, calponin, desmin, S-100, GFAP, NSE and Olig2, in order to assess whether the phenotype was consistent with the tumor histological appearance. Additionally, the expression of EGFR, a marker with potential therapeutic implications in malignant PNSTs, was evaluated. Twenty-one tumors were included. Fourteen cases (66.7%) were positive for one or more muscular markers and were reclassified as perivascular tumors (PWTs). A positive labeling for S-100 was observed in one tumor (4.8%), thus classifi ed as PNST. The other 6 tumors were generically classified as poorly differentiated STSs. No unique histopathological feature was observed within the three groups. NSE and Olig2 labeling was aspecific and not useful for diagnostic purposes. GFAP was negative in all cases. Six cases (28.6%) were positive for EGFR, including the PNST. Even after the application of a wide immunohistochemical panel, distinguishing between PNSTs and PWTs remains a challenge. Finally, a subgroup of cases cannot be classified based on light microscopy alone.

Reclassification of 21 Presumptive Canine Peripheral Nerve Sheath Tumors (PNST) Using a Literature-Based Immunohistochemical Panel

Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, Ozzano dell’Emilia, Bologna,

Acta Veterinaria

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

The aim of this study was to re-evaluate archived samples of canine soft tissue sarcomas (STSs) morphologically consistent with peripheral nerve sheath tumors...

Reclassification of 21 Presumptive Canine Peripheral Nerve Sheath Tumors (PNST) Using a Literature-Based Immunohistochemical Panel

Published Online: Dec 30, 2016

Page range: 455 - 465

Received: Jul 08, 2016

Accepted: Oct 18, 2016

DOI: https://doi.org/10.1515/acve-2016-0039

© by Luciana Mandrioli

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.