TY - JOUR
T1 - Case Report
T2 - Tubal Atypical Placental Site Nodule
AU - Yen, Ting Tai
AU - Anderson, Jean
AU - Shih, Ie Ming
N1 - Publisher Copyright:
© 2022 Lippincott Williams and Wilkins. All rights reserved.
PY - 2022/9/1
Y1 - 2022/9/1
N2 - Placental site nodule (PSN) is a benign proliferation of chorionic-type intermediate trophoblastic cells that forms a tumor-like lesion. Most PSNs are intrauterine, but a few have been reported outside the uterus, including in fallopian tubes. PSN is related to epithelioid trophoblastic tumor (ETT) in that both are composed of chorionic-type intermediate trophoblastic cells, while ETT is hypercellular and contains trophoblastic cells with increased nuclear atypia and a higher Ki-67 proliferation index as compared with PSN. Occasionally, an intermediate stage between a PSN and an ETT is observed, and such a lesion is often recognized as an atypical PSN (aPSN) characterized by trophoblastic cells exhibiting morphologic features in transition from a conventional PSN to an ETT. aPSN has been thought to exhibit benign behavior; however, it has also been reported that up to 15% of aPSN lesions either coexist with, or subsequently develop into, ETT. To the best of our knowledge, there has been no case report of an aPSN in an extrauterine site. Here, we reported a highly unusual case of tubal aPSN, which illustrates several key features associated with PSN and its possible pathogenesis.
AB - Placental site nodule (PSN) is a benign proliferation of chorionic-type intermediate trophoblastic cells that forms a tumor-like lesion. Most PSNs are intrauterine, but a few have been reported outside the uterus, including in fallopian tubes. PSN is related to epithelioid trophoblastic tumor (ETT) in that both are composed of chorionic-type intermediate trophoblastic cells, while ETT is hypercellular and contains trophoblastic cells with increased nuclear atypia and a higher Ki-67 proliferation index as compared with PSN. Occasionally, an intermediate stage between a PSN and an ETT is observed, and such a lesion is often recognized as an atypical PSN (aPSN) characterized by trophoblastic cells exhibiting morphologic features in transition from a conventional PSN to an ETT. aPSN has been thought to exhibit benign behavior; however, it has also been reported that up to 15% of aPSN lesions either coexist with, or subsequently develop into, ETT. To the best of our knowledge, there has been no case report of an aPSN in an extrauterine site. Here, we reported a highly unusual case of tubal aPSN, which illustrates several key features associated with PSN and its possible pathogenesis.
KW - Epithelioid trophoblastic tumor
KW - Placental site nodule
KW - Tubal atypical placental site nodule
UR - http://www.scopus.com/inward/record.url?scp=85116898689&partnerID=8YFLogxK
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U2 - 10.1097/PGP.0000000000000825
DO - 10.1097/PGP.0000000000000825
M3 - Article
C2 - 34570016
AN - SCOPUS:85116898689
SN - 0277-1691
VL - 41
SP - 530
EP - 534
JO - International Journal of Gynecological Pathology
JF - International Journal of Gynecological Pathology
IS - 5
ER -