Pregnancy-related peritoneal ectopic decidua (deciduosis): morphological and clinical evaluation

Our plain-English summary of Pregnancy-related peritoneal ectopic decidua (deciduosis): morphological and clinical evaluation, by F. Bolat, T. Canpolat, E. Tarim (Türk Patoloji Dergisi, 2012).

The study

• Authors: F. Bolat, T. Canpolat, E. Tarim
• Journal: Türk Patoloji Dergisi
• Published: 2012;28(1):56-60
• Cited by: 15 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objective: Ectopic decidual reaction (deciduosis) can be seen rarely on the peritoneum during laparotomy for a cesarean section for pregnancy, in addition to the ovary and cervix. The aim of this study was to evaluate the clinical, histopathological, immunohistochemical characteristics of ectopic decidua cases that were incidentally found in the peritoneum during a cesarean section.

Material And Method: A total of seven cases where decidualization was found in the peritoneal biopsy taken during pregnancy at the Baskent University Medical Faculty Adana Teaching and Training Hospital Department of Pathology were included in this study. The clinical features of the cases were obtained from their clinical folders. The morphological findings were recorded and the peritoneal biopsies were analyzed with keratin Pan Ab-1, calretinin, vimentin, HMB-45 and progesterone receptor antibody for immunohistochemical analysis.

Results: The mean age for the seven cases was 36±4.16. The gestational age was 33 to 39 (mean 37.2) weeks. Microscopic evaluation revealed decidualized cells that were large polygonal and eosinophilic, some with vacuolated cytoplasm, that formed small nodules under the mesothelium of the peritoneum in all cases. Immunohistochemical staining showed positive staining of the cell cytoplasm with vimentin and positive staining of the cell nucleus with the progesterone receptor antibody in the decidual cells. Calretinin, keratin and HMB-45 stains were negative.

Conclusion: Pregnancy-related peritoneal deciduosis develops with the effect of progesterone in pregnancy. It disappears without complication in the postpartum period. Immunohistochemistry may help the differential diagnosis of peritoneal deciduosis where problems are experienced differentiating the case from malignant mesothelioma or metastatic tumor.

In plain English

This article from Turkey was a pathology case series, not a study of asbestos exposure. The authors described seven pregnant women at Başkent University's Adana center whose peritoneal biopsies, taken during pregnancy, showed decidual cells (cells resembling those of the womb lining in pregnancy) on the lining of the abdomen. This condition is called peritoneal deciduosis. The women's mean age was 36 plus or minus 4.16 years (range 31 to 43), and they were 33 to 39 weeks pregnant (mean 37.2). None had a history or symptoms of endometriosis. In three women a single yellow nodule 1 to 4 mm across was seen; the other four had no clear nodule. Under the microscope, the decidual cells showed no nuclear pleomorphism, hyperchromasia or mitotic activity. They stained positive for vimentin and progesterone receptor and negative for calretinin, keratin and HMB-45. The authors concluded that this tissue is benign and resolves without treatment after delivery. They also concluded that immunohistochemistry may help tell it apart from malignant mesothelioma or metastatic tumor in difficult cases.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: case series (pathology review of seven biopsy cases, with clinical records)
• Who was studied: Seven pregnant women with decidual cells in peritoneal biopsies, Başkent University Adana Research and Medical Center, Department of Pathology, Turkey; mean age 36 plus or minus 4.16 (31 to 43) years, gestational age 33 to 39 (mean 37.2) weeks; study dates not given
• Exposure: No asbestos exposure was studied. The condition examined was ectopic decidua in pregnancy, which the authors attribute to the effect of progesterone. Mesothelioma is mentioned only as a disease to be distinguished from it.
• Main results:
  • None of the seven women had a history or symptoms of endometriosis
  • In three cases the biopsy was taken from a small nodule-like lesion during cesarean section; in the other cases it came from areas with peritoneal adhesions
  • Three cases had a single yellow nodule 1 to 4 mm in diameter; the other four had no significant nodule visible to the eye
  • The decidual cells showed no nuclear pleomorphism, hyperchromasia or mitotic activity
  • Two cases had mild lymphocytic infiltration and lymphoid aggregates; no granulomatous structure was seen
  • Two cases, both at the 38th week of pregnancy, had vacuolated decidual cells and a myxoid stroma
  • The decidual cells stained positive for vimentin (cytoplasm) and progesterone receptor (nucleus)
  • Calretinin, keratin and HMB-45 stains were negative in the decidual cells
  • The lesions showed no diffuse distribution, no old or new hemorrhagic foci and no endometrial glands or stroma; the authors interpreted the cases as pregnancy-related ectopic decidua rather than decidualized endometriosis
• The authors' conclusion: The authors concluded that pregnancy-related ectopic decidual tissue is benign, resolves without treatment after delivery, and should be kept in mind in differential diagnosis. They also concluded that immunohistochemistry may help distinguish it from malignant mesothelioma or metastatic tumor in difficult cases.

Topics

Medical terms in this study, explained in our Lexicon: Peritoneum, Laparotomy, Biopsy, Pathology, Calretinin, Eosinophilic, Mesothelium, Immunohistochemistry.

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