Free peritoneal cyst with histologic properties of amniotic epithelium observed in a woman pregnant with twins.
We report an interesting case of a free peritoneal cyst in a woman pregnant with twins. As far as we know, a cyst with histologic properties similar to the metaplastic stratified squamous epithelium of the amnion has not been reported. A 20-year-old Japanese woman pregnant with twins underwent cesarean section at 29 weeks of gestation. A simple serous cyst 5 cm in diameter was found at excavatio vesicouterina. The cyst was not attached to the surrounding organs, and was located independent of any other tissues in the patient's abdominal cavity. Histologic examination revealed that the cyst wall was composed of three major layers (epithelium, mesenchyme and mesothelium) with no vessels. Immunohistochemical staining with human chorionic gonadotropin (HCG), cytokeratins, vimentin, placental alkaline phosphatase (PAP) and cluster of differentiation (CD) 31, showed that the cyst wall had characteristic features of the amniotic membrane. Alleles of the patient's husband were not identified when the cyst was genotyped. Some of the patient's loci were deleted and others showed a structurally heterogeneous pattern. These findings suggest that the cyst was derived not from the ovum parthenogenesis, but from the patient's somatic cells and could have been incubated by ascites.
Department of Obstetrics, Center for Perinatal Medicine, Nagano Children's Hospital, Azumino, Japan.
Tsuguhiro
T
Horikoshi
Akihiko
A
Kikuchi
Kyoko
K
Ono
Mariko
M
Kita
Kimiyo
K
Takagi
Yoshifumi
Y
Ogiso
D002585:Cesarean Section; D003560:Cysts / Q000473:pathology*; D005260:Female; D006801:Humans; D010534:Peritoneal Neoplasms / Q000473:pathology*; D011247:Pregnancy; D011272:Pregnancy, Multiple; D055815:Young Adult