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{{ Infobox diagnosis | |||
| Name = {{PAGENAME}} | |||
| Image = Meconium-laden_macrophages_high_mag.jpg | |||
| Width = | |||
| Caption = Meconium-laden macrophages. [[H&E stain]]. | |||
| Micro = macrophages with brown fine granular pigment in the amnion +/- chorion | |||
| Subtypes = | |||
| LMDDx = hemorrhage | |||
| Stains = PASD +ve, Prussian blue -ve | |||
| IHC = | |||
| EM = | |||
| Molecular = | |||
| IF = | |||
| Gross = green discolourization of fetal membranes | |||
| Grossing = | |||
| Site = [[placenta|placental membranes]] | |||
| Assdx = +/-[[chorioamnionitis]] | |||
| Syndromes = | |||
| Clinicalhx = +/-non-reassuring fetal heart rate | |||
| Signs = | |||
| Symptoms = | |||
| Prevalence = uncommon | |||
| Bloodwork = | |||
| Rads = | |||
| Endoscopy = | |||
| Prognosis = benign | |||
| Other = | |||
| ClinDDx = | |||
}} | |||
'''Placental meconium''', also known as '''[[meconium]] staining''', is associated with fetal distress. | |||
==General== | |||
*Associated with fetal distress. | |||
*Small amount - at term - is considered to be normal. | |||
Other meconium-related pathology: | |||
*[[Meconium peritonitis]]. | |||
*[[Meconium ileus]]. | |||
==Gross== | |||
*Fetal membranes with a green discolourization. | |||
==Microscopic== | |||
Features:<ref>ALS. 6 Febraury 2009.</ref> | |||
*Meconium histiocytes - '''key feature'''. | |||
**Macrophages with brown fine granular pigment. | |||
*Pseudostratified epithelium (amnion) - low power. | |||
*Amnion - columnar morphology (normally cuboidal). | |||
*"Drop-out" of individual amnion cells / loss of individual cells. | |||
Time of meconium passage:<ref name=pmid2413412>{{cite journal |author=Miller PW, Coen RW, Benirschke K |title=Dating the time interval from meconium passage to birth |journal=Obstet Gynecol |volume=66 |issue=4 |pages=459–62 |year=1985 |month=October |pmid=2413412 |doi= |url=}}</ref> | |||
*<1 h - no staining of membranes. | |||
*1-3 h - amnion is stained. | |||
*>3 h - chorion is stained. | |||
DDx: | |||
*Hemosiderin-laden macrophages. | |||
**This is sorted-out with an iron stain -- see below. | |||
Notes: | |||
*The above time course is disputed - in vitro experiments suggest it is considerably longer.<ref name=pmid19031358>{{cite journal |author=Funai EF, Labowsky AT, Drewes CE, Kliman HJ |title=Timing of fetal meconium absorption by amnionic macrophages |journal=Am J Perinatol |volume=26 |issue=1 |pages=93–7 |year=2009 |month=January |pmid=19031358 |doi=10.1055/s-0028-1103028 |url=}}</ref> | |||
===Images=== | |||
<gallery> | |||
Image:Meconium-laden_macrophages_high_mag.jpg | Meconium-laden macrophages - high mag. (WC) | |||
Image:Meconium-laden_macrophages_intermed_mag.jpg | Meconium-laden macrophages - intermed. mag. (WC) | |||
</gallery> | |||
==Special stains== | |||
*Hemosiderin +ve in hemosiderin-laden macrophages. | |||
*PAS +ve in meconium-laden macrophages.<ref name=pmid11268705>{{cite journal |author=Povýsil C, Bennett R, Povýsilová V |title=CD 68 positivity of the so-called meconium corpuscles in human foetal intestine |journal=Cesk Patol |volume=37 |issue=1 |pages=7–9 |year=2001 |month=January |pmid=11268705 |doi= |url=}}</ref> | |||
Useful to differentiate hemosiderin-laden macrophages and meconium laden macrophages: | |||
*Hemosiderin stain -- +ve for old blood. | |||
**Prussian-blue stain = hemosiderin stain.<ref>{{cite journal |author=Sienko A, Altshuler G |title=Meconium-induced umbilical vascular necrosis in abortuses and fetuses: a histopathologic study for cytokines |journal=Obstet Gynecol |volume=94 |issue=3 |pages=415?0 |year=1999 |month=September |pmid=10472870 |doi= |url=}}</ref> | |||
Notes: | |||
*PAS-D -- +ve in meconium... though may rarely stain hemosiderin. | |||
*Meconium contains bile.<ref>{{cite journal |author=Sienko A, Altshuler G |title=Meconium-induced umbilical vascular necrosis in abortuses and fetuses: a histopathologic study for cytokines |journal=Obstet Gynecol |volume=94 |issue=3 |pages=415?0 |year=1999 |month=September |pmid=10472870 |doi= |url=}}</ref> | |||
==Sign out== | |||
<pre> | |||
PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, BIRTH: | |||
- FETAL MEMBRANES WITH MECONIUM-LADEN MACROPHAGES, NEGATIVE FOR CHORIOAMNIONITIS. | |||
- THREE VESSEL UMBILICAL CORD WITHIN NORMAL LIMITS. | |||
- PLACENTAL DISC WITH THIRD TRIMESTER VILLI WITHIN NORMAL LIMITS. | |||
</pre> | |||
<pre> | |||
COMMENT: | |||
A PAS-D stain and Prussian blue stain were used to confirm the presence of meconium. | |||
</pre> | |||
===Not definite=== | |||
<pre> | |||
PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, CESAERIAN SECTION: | |||
- EARLY CHORIOAMNIONITIS. | |||
- FETAL MEMBRANES WITH FOCAL AMNION CELL DROP-OUT AND RARE PIGMENTED | |||
CELLS SUGGESTIVE OF MECONIUM. | |||
- THREE VESSEL UMBILICAL CORD WITHIN NORMAL LIMITS. | |||
- PLACENTAL DISC WITH THIRD TRIMESTER VILLI. | |||
</pre> | |||
==See also== | |||
*[[Placenta]]. | |||
*[[Chorioamnionitis]]. | |||
==References== | |||
{{Reflist|2}} | |||
[[Category:Placenta]] | |||
[[Category:Diagnosis]] | [[Category:Diagnosis]] |
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