TY - JOUR
T1 - INSM1 Expression in Angiosarcoma
AU - Warmke, Laura M.
AU - Tinkham, Emma Grace
AU - Ingram, Davis R.
AU - Lazar, Alexander J.
AU - Panse, Gauri
AU - Wang, Wei Lien
N1 - Publisher Copyright:
© 2020 American Society for Clinical Pathology.
PY - 2021/4/1
Y1 - 2021/4/1
N2 - Objectives: Aberrant expression of neuroendocrine markers has been reported in angiosarcomas and can occasionally result in diagnostic confusion. The aim of this study was to evaluate the expression of insulinoma-associated protein 1 (INSM1), a marker for neuroendocrine differentiation, in angiosarcomas as well as other sarcomas. Methods: Tissue microarrays, including angiosarcoma, Ewing sarcoma, desmoplastic small round cell tumor (DSRCT), clear cell sarcoma, synovial sarcoma, leiomyosarcoma, alveolar soft part sarcoma, epithelioid sarcoma, and undifferentiated pleomorphic sarcoma, were evaluated for expression of INSM1. The extent of immunoreactivity was graded according to the percentage of positive tumor cell nuclei (0, no staining; 1+, <5%; 2+, 5%-25%; 3+, 26%-50%; 4+, 51%-75%; and 5+, 76%-100%), and the intensity of staining was graded as weak, moderate, or strong. Results: INSM1 expression was found in a subset of angiosarcomas (n = 24/94, 26%; majority 5+, weak to moderate), as well as DSRCTs (n = 7/62, 11%; 2+, weak to strong) and rarely synovial sarcomas (n = 3/76, 4%; 2+, moderate to strong). No INSM1 expression was detected in the other sarcomas. Conclusions: Aberrant expression of INSM1 can be seen in a subset of angiosarcomas often with diffuse labeling. Other sarcomas that can rarely demonstrate small cell morphology and focal INSM1 expression include DSRCT and synovial sarcoma.
AB - Objectives: Aberrant expression of neuroendocrine markers has been reported in angiosarcomas and can occasionally result in diagnostic confusion. The aim of this study was to evaluate the expression of insulinoma-associated protein 1 (INSM1), a marker for neuroendocrine differentiation, in angiosarcomas as well as other sarcomas. Methods: Tissue microarrays, including angiosarcoma, Ewing sarcoma, desmoplastic small round cell tumor (DSRCT), clear cell sarcoma, synovial sarcoma, leiomyosarcoma, alveolar soft part sarcoma, epithelioid sarcoma, and undifferentiated pleomorphic sarcoma, were evaluated for expression of INSM1. The extent of immunoreactivity was graded according to the percentage of positive tumor cell nuclei (0, no staining; 1+, <5%; 2+, 5%-25%; 3+, 26%-50%; 4+, 51%-75%; and 5+, 76%-100%), and the intensity of staining was graded as weak, moderate, or strong. Results: INSM1 expression was found in a subset of angiosarcomas (n = 24/94, 26%; majority 5+, weak to moderate), as well as DSRCTs (n = 7/62, 11%; 2+, weak to strong) and rarely synovial sarcomas (n = 3/76, 4%; 2+, moderate to strong). No INSM1 expression was detected in the other sarcomas. Conclusions: Aberrant expression of INSM1 can be seen in a subset of angiosarcomas often with diffuse labeling. Other sarcomas that can rarely demonstrate small cell morphology and focal INSM1 expression include DSRCT and synovial sarcoma.
KW - Angiosarcoma
KW - INSM1
KW - Immunohistochemistry
KW - Neuroendocrine differentiation
KW - Vascular markers
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U2 - 10.1093/ajcp/aqaa168
DO - 10.1093/ajcp/aqaa168
M3 - Article
C2 - 33210141
AN - SCOPUS:85101340469
SN - 0002-9173
VL - 155
SP - 575
EP - 580
JO - American journal of clinical pathology
JF - American journal of clinical pathology
IS - 4
ER -