2016, vol. 66, br. 4, str. 455-465
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Reklasifikacija 21 tumora ovojnica perifernih nerava pasa (PNST) upotrebom imunohistohemijskog panela prema preporukama iz literature
Reclassification of 21 presumptive canine peripheral nerve sheath tumors (PNST) using a literature-based immunohistochemical panel
Department of Veterinary Medical Sciences, University of Bologna, Ozzano dell'Emilia, Bologna, Italy
e-adresa: luciana.mandrioli@unibo.it
Sažetak
Cilj studije je bio da se obavi re-evaluacija arhiviranih uzoraka sarkoma mekih tkiva (soft tissue sarcomas, eng. -SSTs) koji su morfološki odgovarali tumorima ovojnica perifernih nerava pasa (peripheral nerve sheath tumors, eng. - PNSTs). U svakom pojedinačnom slučaju, primenjen je imunohistohemijski panel koji je uključivao α-SMA, calponin, desmin, S-100, GFAP, NSE i Olig2, a u cilju procene da li je fenotip bio konzistentan sa histološkim nalazom na tumoru. Pored toga, obavljena je i evaluacija EGFR, koji ima potencijalne terapijske implikacije u odnosu na PNST. Studijom je obuhvaćen 21 tumor. Četrnaest slučajeva (66,7%) je bilo pozitivno na najmanje jedan marker mišićnog tkiva pri čemu je obavljena reklasifikacija kao perivaskularni tumori (perivascular tumors, eng.- PVTs). Pozitivno bojenje sa S-100 bilo je uočeno kod jednog tumora (4,8%) pa je taj uzorak klasifikovan kao PNST. Ostalih 6 tumora, su klasifikovani kao slabo diferentovani STS. U sve tri grupe, nisu uočene jedinstvene histopatološke osobine. NSE i Olig2 obeležavanje nije bilo specifično i nije moglo da se upotrebi u dijagnostičke svrhe. GFAP je bio negativan u svakom slučaju. Šest uzoraka tumora (28,6%) su bili pozitivni na EGFR, uključujući i PNST. Čak i posle primene šireg imunohistolohemijskog panela, razlikovanje između PNST i PVT i dalje predstavlja značajan problem i izazov za patologe. Konačno, nije moguće svrstavanje tumora u podgrupe, samo na osnovu svetlosne mikroskopije.
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 classified 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 a specific 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.
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