TY - JOUR
T1 - Diandric triploid hydatidiform mole with loss of maternal chromosome 11
AU - DeScipio, Cheryl
AU - Haley, Lisa
AU - Beierl, Katie
AU - Pandit, Ashwini P.
AU - Murphy, Kathleen M.
AU - Ronnett, Brigitte M.
PY - 2011/10/1
Y1 - 2011/10/1
N2 - Distinction of hydatidiform moles (HM) from nonmolar specimens and their subclassification as complete (CHM) versus partial hydatidiform mole (PHM) are important for clinical practice and investigational studies to refine ascertainment of risk of persistent gestational trophoblastic disease (GTD), which differs among these entities. Immunohistochemical analysis of p57 expression, a paternally imprinted maternally expressed gene on 11p15.5, and molecular genotyping are useful for improving diagnosis. CHMs are characterized by androgenetic diploidy, with loss of p57 expression due to lack of maternal DNA. Loss of p57 expression distinguishes CHMs from both PHMs (diandric triploidy) and nonmolar specimens (biparental diploidy), which retain expression. We report a unique HM characterized by morphologic features suggesting an early CHM, including lack of p57 expression by immunohistochemistry, but with genetic features more in keeping with a PHM. Specifically, molecular genotyping by short tandem repeat markers provided evidence to support interpretation as a PHM by demonstrating allele patterns and ratios most consistent with diandric triploidy, with evidence of loss of the maternal copy of chromosome 11 to explain the lack of p57 expression. This case illustrates the value of combined traditional pathologic and ancillary molecular techniques for refined diagnosis of molar specimens. It also raises questions regarding which modalities should be used to ultimately define the subtypes of HMs and whether chromosomal losses or gains, particularly involving imprinted genes such as p57, might play a role in modifying risk of persistent GTD.
AB - Distinction of hydatidiform moles (HM) from nonmolar specimens and their subclassification as complete (CHM) versus partial hydatidiform mole (PHM) are important for clinical practice and investigational studies to refine ascertainment of risk of persistent gestational trophoblastic disease (GTD), which differs among these entities. Immunohistochemical analysis of p57 expression, a paternally imprinted maternally expressed gene on 11p15.5, and molecular genotyping are useful for improving diagnosis. CHMs are characterized by androgenetic diploidy, with loss of p57 expression due to lack of maternal DNA. Loss of p57 expression distinguishes CHMs from both PHMs (diandric triploidy) and nonmolar specimens (biparental diploidy), which retain expression. We report a unique HM characterized by morphologic features suggesting an early CHM, including lack of p57 expression by immunohistochemistry, but with genetic features more in keeping with a PHM. Specifically, molecular genotyping by short tandem repeat markers provided evidence to support interpretation as a PHM by demonstrating allele patterns and ratios most consistent with diandric triploidy, with evidence of loss of the maternal copy of chromosome 11 to explain the lack of p57 expression. This case illustrates the value of combined traditional pathologic and ancillary molecular techniques for refined diagnosis of molar specimens. It also raises questions regarding which modalities should be used to ultimately define the subtypes of HMs and whether chromosomal losses or gains, particularly involving imprinted genes such as p57, might play a role in modifying risk of persistent GTD.
KW - hydatidiform mole
KW - immunohistochemistry
KW - molecular genotype
KW - p57
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U2 - 10.1097/PAS.0b013e31822d5cff
DO - 10.1097/PAS.0b013e31822d5cff
M3 - Article
C2 - 21881485
AN - SCOPUS:80053379764
SN - 0147-5185
VL - 35
SP - 1586
EP - 1591
JO - American Journal of Surgical Pathology
JF - American Journal of Surgical Pathology
IS - 10
ER -