Products of conception

Author: Mikael Häggström

Comprehensiveness

On this resource, the following formatting is used for comprehensiveness:

• Minimal depth
• (Moderate depth)
• ((Comprehensive))

Gross processing

Look up the gestational age of the pregnancy.

• Look for fetal tissue (fetus, fetal membranes or chorionic villi). If chorionic villi are found, no lengthy search is needed for other kinds of fetal tissue, just a quick look for obvious ones. Membranous material is less reliable, and may still indicate further sampling. Inspect any found fetal tissue for gross anomalies. If found, submit one piece of the fetus and one piece of the placenta.

• 
  Fresh chorionic villi (arrows), surrounded by decidua, at 10 weeks of gestational age.
• 
  Chorionic villi (arrow) become more distinguished when held in fluid, having a fibrillary shape
• 
  Fresh chorionic villi (left) compared to decidua (right).
• 
  Chorionic villi become more pale when fixed in formalin.
• 
  Macropathology of fixed umbilical cord, amnion and chorionic villi at 7-13 weeks of gestational age
• 
  Fresh chorionic villi in a term placenta for comparison, being more granular.

• If fetal parts are not visually found, search for diagnostic placental tissue, which is soft and shaggy or spongy (as opposed to membranous, which is likely to be decidua or blood clots).
• If no fetal or placental tissue is found, all presented tissue generally needs to be submitted.

Gross report

(Labeled - products of conception.) The specimen (is received <<fresh / in formalin>>) and consists of multiple fragments of soft tan-pink decidua, blood clots and amniotic sac measuring about 5 cc in aggregate. The intact amniotic sac measures 2.3 cm in greatest dimension. Fetal tissue is identified within the amniotic sac, measuring 1.0 cm in crown-rump length. Representative sections are submitted for microscopic examination (in 1 cassette).

Microscopy

The most important is to detect the presence of chorionic villi.

• 
  Products of conception, with chorionic villi (arrow) among decidualized endometrium
• 
  Immature chorionic villi, having loose stroma and few capillaries.
• 
  Necrotic chorionic villi in a tubal pregnancy.
• 
  Scantly cellular decidua may look like chorionic villi, but lack the thick trophoblastic lining.

In the absence of chorionic villi, look for implantation site intermediate trophoblasts (ISITs):

• 
  ISITs, having relatively large and dark nuclei.
• 
  Histology of decidua for comparison, having smaller and brighter nuclei.

• In the absence of both chorionic villi and ISITs, preferably perform cytokeratin immunostaining of each tissue sample, such as CAM5.2.
• In the absence of chorionic villi and ISITs even after staining, call the clinician, since there may be an ectopic pregnancy.

Microscopy report

Examples:

((Products of conception:)) Products of conception, including immature chorionic villi, corresponding to first trimester pregnancy. ((Spontaneous abortion, clinically.))

((Products of conception:)) Fragments of focally necrotic decidua and implantation site, consistent with intrauterine products of conception. Negative for chorionic villi.

Main page

• Main page of Patholines