TY - JOUR
T1 - Pericytoma with t(7;12) and ACTB-GLI1 Fusion
T2 - Reevaluation of an Unusual Entity and its Relationship to the Spectrum of GLI1 Fusion-related Neoplasms
AU - Kerr, Darcy A.
AU - Pinto, Andre
AU - Subhawong, Ty K.
AU - Wilky, Breelyn A.
AU - Schlumbrecht, Matthew P.
AU - Antonescu, Cristina R.
AU - Nielsen, G. Petur
AU - Rosenberg, Andrew E.
N1 - Publisher Copyright:
Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2019/12/1
Y1 - 2019/12/1
N2 - The entity "pericytoma with t(7;12)" was described as a rare, distinct perivascular myoid neoplasm provisionally classified within the family of myopericytic tumors that demonstrates t(7;12)(p22;q13) translocation with resultant ACTB-GLI1 fusion and biologically was felt to behave in an indolent fashion. However, a recent study showed that tumors with this and similar translocations may have variable morphology and immunohistochemical phenotype with inconsistent myopericytic characteristics and a propensity for metastasis, raising questions regarding the most appropriate classification of these neoplasms. Herein, we report 3 additional patients with tumors harboring t(7;12) and ACTB-GLI1 fusion. The tumors arose in adults and involved the proximal tibia and adjacent soft tissues, scapula and adjacent soft tissues, and ovary. All tumors were composed of round-to-ovoid cells with a richly vascularized stroma with many small, delicate, branching blood vessels, where the neoplastic cells were frequently arranged in a perivascular distribution. Both tumors involving bone showed histologic features of malignancy. By immunohistochemistry, all tested tumors were at least focally positive for smooth muscle actin (3/3) and CD99 (patchy) (2/2), with variable staining for muscle-specific actin (2/3), S100 protein (1/3), epithelial membrane antigen (2/3), and pan-keratin (1/3); all were negative for desmin and WT1 (0/3). The 2 patients with bone tumors developed metastases (27 and 84 mo after diagnosis). Whether these tumors are best classified as malignant myopericytoma variants or an emerging translocation-associated sarcoma of uncertain differentiation remains to be fully clarified; however, our study further documents the potential for these tumors to behave in an aggressive fashion, sometimes over a prolonged clinical course.
AB - The entity "pericytoma with t(7;12)" was described as a rare, distinct perivascular myoid neoplasm provisionally classified within the family of myopericytic tumors that demonstrates t(7;12)(p22;q13) translocation with resultant ACTB-GLI1 fusion and biologically was felt to behave in an indolent fashion. However, a recent study showed that tumors with this and similar translocations may have variable morphology and immunohistochemical phenotype with inconsistent myopericytic characteristics and a propensity for metastasis, raising questions regarding the most appropriate classification of these neoplasms. Herein, we report 3 additional patients with tumors harboring t(7;12) and ACTB-GLI1 fusion. The tumors arose in adults and involved the proximal tibia and adjacent soft tissues, scapula and adjacent soft tissues, and ovary. All tumors were composed of round-to-ovoid cells with a richly vascularized stroma with many small, delicate, branching blood vessels, where the neoplastic cells were frequently arranged in a perivascular distribution. Both tumors involving bone showed histologic features of malignancy. By immunohistochemistry, all tested tumors were at least focally positive for smooth muscle actin (3/3) and CD99 (patchy) (2/2), with variable staining for muscle-specific actin (2/3), S100 protein (1/3), epithelial membrane antigen (2/3), and pan-keratin (1/3); all were negative for desmin and WT1 (0/3). The 2 patients with bone tumors developed metastases (27 and 84 mo after diagnosis). Whether these tumors are best classified as malignant myopericytoma variants or an emerging translocation-associated sarcoma of uncertain differentiation remains to be fully clarified; however, our study further documents the potential for these tumors to behave in an aggressive fashion, sometimes over a prolonged clinical course.
KW - ACTB
KW - GLI1
KW - myopericytoma
KW - pericytoma
KW - sarcoma
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UR - http://www.scopus.com/inward/citedby.url?scp=85074872589&partnerID=8YFLogxK
U2 - 10.1097/PAS.0000000000001360
DO - 10.1097/PAS.0000000000001360
M3 - Article
C2 - 31567194
AN - SCOPUS:85074872589
VL - 43
SP - 1682
EP - 1692
JO - American Journal of Surgical Pathology
JF - American Journal of Surgical Pathology
SN - 0147-5185
IS - 12
ER -