TY - JOUR
T1 - Insulinoma-associated protein 1 immunostaining for various types of neuroendocrine tumors on FNA smears
AU - Hou, Tieying
AU - Gan, Qiong
AU - Joseph, Cicily T.
AU - Sun, Xiaoping
AU - Gong, Yun
N1 - Funding Information:
This study was supported by a Mentor Research Fund Award (to Tieying Hou and Qiong Gan) from The University of Texas MD Anderson Cancer Center. The University of Texas MD Anderson Cancer Center is supported by the National Institutes of Health (grant P30 CA016672).
Publisher Copyright:
© 2020 American Cancer Society
PY - 2020/10/1
Y1 - 2020/10/1
N2 - Background: Insulinoma-associated protein 1 (INSM1) has recently emerged as a reliable nuclear immunostaining marker for detecting neuroendocrine tumors (NETs) in paraffin-embedded surgical samples and cytologic cell blocks, but the reliability of INSM1 staining on cytologic smears is understudied. This study investigated the performance of INSM1 staining on cytologic smears for the detection of various NETs in comparison with chromogranin (CG) and synaptophysin (SYN). Methods: INSM1, CG, and SYN were stained on cytologic smears of 70 NETs, including 20 pancreatic NETs, 10 lung carcinoid tumors, 11 small cell lung carcinomas (SCLCs), 10 medullary thyroid carcinomas, 10 Merkel cell carcinomas, 4 thymic atypical carcinoid tumors, and 5 olfactory neuroblastomas. The detection rate, the percentage of positive cells, and the staining intensity were recorded. Results: The overall detection rate of INSM1 (94%) was higher than the rates of CG (79%) and SYN (89%). The detection rate of INSM1 was higher than the rates of CG and SYN in SCLC, Merkel cell carcinoma, and olfactory neuroblastoma; higher than the rate of CG and equal to the rate of SYN in pancreatic NETs and medullary thyroid carcinoma; equal to the rate of CG and higher than the rate of SYN in thymic atypical carcinoid tumors; and equal to the rate of CG and lower than the rate of SYN in lung carcinoid tumors. INSM1 staining was easier to interpret than CG and SYN staining, especially in high-grade NETs. Conclusions: INSM1 can be reliably stained on cytologic smears and outperforms CG and SYN in the verification of clinically or radiologically suspected NETs.
AB - Background: Insulinoma-associated protein 1 (INSM1) has recently emerged as a reliable nuclear immunostaining marker for detecting neuroendocrine tumors (NETs) in paraffin-embedded surgical samples and cytologic cell blocks, but the reliability of INSM1 staining on cytologic smears is understudied. This study investigated the performance of INSM1 staining on cytologic smears for the detection of various NETs in comparison with chromogranin (CG) and synaptophysin (SYN). Methods: INSM1, CG, and SYN were stained on cytologic smears of 70 NETs, including 20 pancreatic NETs, 10 lung carcinoid tumors, 11 small cell lung carcinomas (SCLCs), 10 medullary thyroid carcinomas, 10 Merkel cell carcinomas, 4 thymic atypical carcinoid tumors, and 5 olfactory neuroblastomas. The detection rate, the percentage of positive cells, and the staining intensity were recorded. Results: The overall detection rate of INSM1 (94%) was higher than the rates of CG (79%) and SYN (89%). The detection rate of INSM1 was higher than the rates of CG and SYN in SCLC, Merkel cell carcinoma, and olfactory neuroblastoma; higher than the rate of CG and equal to the rate of SYN in pancreatic NETs and medullary thyroid carcinoma; equal to the rate of CG and higher than the rate of SYN in thymic atypical carcinoid tumors; and equal to the rate of CG and lower than the rate of SYN in lung carcinoid tumors. INSM1 staining was easier to interpret than CG and SYN staining, especially in high-grade NETs. Conclusions: INSM1 can be reliably stained on cytologic smears and outperforms CG and SYN in the verification of clinically or radiologically suspected NETs.
KW - Merkel cell carcinoma
KW - carcinoid
KW - cytology
KW - insulinoma-associated protein 1 (INSM1)
KW - medullary thyroid carcinoma
KW - neuroblastoma
KW - pancreatic
KW - small cell carcinoma
KW - smear
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U2 - 10.1002/cncy.22310
DO - 10.1002/cncy.22310
M3 - Article
C2 - 32573984
AN - SCOPUS:85087218534
SN - 1934-662X
VL - 128
SP - 725
EP - 732
JO - Cancer Cytopathology
JF - Cancer Cytopathology
IS - 10
ER -