Massive Perivillous Fibrin Deposition / Maternal
Floor Infarction (MFI)
Epidemiology and Etiology:
- Up to 1 in 200 placentas
- Unknown etiology but suggested are:
- Congenital infection
- Immune mediated rejection
- Abnormal extrafillous
trophoblastic proliferation
- Abnormal host/placental interaction
- Maternal thrombophilias
Common sites:
Gross features:
- Corrugated appearance of maternal surface rather
than normal cotyledonary development
- Thick, stiffened, often yellow floor of the
placenta
- Diffuse gray penetration of villous tissue on
sectioning
- Does not always involve the entire floor and
may spare portions of the villous tissue
- Ultrasonographic
criteria for the diagnosis of MFI have been established
Histologic features:
- Decidual
floor is heavily infiltrated by fibrinoid
- Also disseminates throughout the villous tissue
- Net-like pattern of fibrinoid
encasing villi
- Syncitiotrophoblast degenerates and eventually disappears completely over time
- Thickened trophoblastic basal lamina then
surrounds the fibrotic villous stroma
- Chronic villitis
sometimes associated
- Fetal vessels sometimes remain intact but
ultimately become obliterated
- Proliferation of extravillous
trophoblast occasionally associated
Immunophenotype:
Marker:
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Sensitivity:
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Specificity:
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Molecular features:
Other features:
- Strongly correlated with IUGR, IUFD, neurologic
impairment
- Microcephaly has been described
- 30% recurrence rate in subsequent pregnancies
- Elevations in maternal serum alpha-fetoprotein
References: