Ectopic Liver Within the Placental Parenchyma of a Stillborn Fetus

Heterotopic Hepatic Tissue in the Placenta: A Case Report

Heterotopic hepatic tissue in placenta or umbilical cord is rare. The exact mechanism by which this heterotopia occurs has not been fully understood but is thought to be related to yolk sac primordia. To date, a handful of such cases have been reported. We present a case of heterotopic liver tissue within a chorionic stem villus of a 37 week-growth restricted neonate and describe the tissue morphology and its immunohistochemistry workup.

Intraplacental Hepatic Heterotopia

Background: Placental hepatic heterotopia is a benign lesion with unclear histogenesis hypothesized to be of hepatocytic differentiation of yolk sac elements. Of the 14 hepatic heterotopia cases previously reported, 12 cases occurred in preterm labor.Case report: A case of intraplacental hepatic heterotopia in a 27-year-old female with pre-term delivery at 31 + 5 weeks gestational age is described. Histopathological examination revealed a well-demarcated lesion with cohesive, monotonous cells and pale to clear cytoplasm. The differential diagnoses of this lesion included benign, primary and metastatic malignant entities. The lesional cells expressed HepPar-1, CAM 5.2, Glypican-3, and AFP, consistent with cells of hepatic origin.Conclusion: Intraplacental hepatic heterotopia is associated with premature labor. Distinguishing this lesion from maternal and fetal malignancies with similar histopathological presentation has important clinical implications in patient care.

Ectopic Fetal Liver Tissue in the Placenta of a Twin Pregnancy: A Case Report and Review of Literature

Ectopic liver tissue represents a rare entity and is mostly attributed to events occurring during embryogenesis. Previous case reports documented the presence of fetal liver parenchyma within temporarily developed organs during pregnancy, such as the placenta or the umbilical cord. Moreover, the terminology of these benign findings varies from “ectopic liver” to “hepatocellular adenoma-like neoplasm” or “hepatocellular adenoma”. Ancillary tests performed on these lesions have shown positive immunohistochemical staining for hepatocellular origin marker HepPar-1. Only one recent case report comprising molecular analysis showed no beta-catenin gain-of-function mutation. We report a case of ectopic liver in one placenta of a twin pregnancy, with an updated review of literature.

Hepatic and Adrenocortical Choristomas in the Placenta

Background Hepatic and adrenocortical choristomas are unusual findings in the placenta. This meta-analysis includes our own case report and 23 previously reported cases. We searched for patterns of associated placental, fetal and maternal aberrations in order to determine whether these choristomas are clinically relevant. Case report: In our case, abortion was induced due to fetal central nervous system and renal malformations. In the placenta a hepatic choristoma (<0.1 cm), thrombangiitis obliterans and a single umbilical artery were found. Results: In the literature, the majority of lesions were ≤1.0 cm (n = 21/24, 87.5%) and two hepatic choristomas manifested within chorangiomas. In a subfraction of cases, we found an association with twin/triple pregnancies (n = 6/24, 25%) and heterogeneous non-hepatic/non-adrenal malformations in fetuses (n = 4/24, 17%). Conclusion: Hepatic and adrenocortical choristomas are benign, could be based on focal epigenetic changes and might be related to chorangiomas but are not associated with a particular disease pattern or risk profile.

Heterotopic Adipose Tissue in the Placental Parenchyma: Case Report

Objective: Reports of heterotopic tissue in the placenta are few and mainly include liver and adrenal cells. We report on adipose tissue found in the placenta. Case report: We present the case of a microscopic finding in a 25-year-old's placenta who suffered from hypertensive disorder in pregnancy. During routine microscopic study, we observed a heterotopic, benign, circumscribed and intervillous nodule of adipose tissue. Conclusion: To our knowledge, there is no other reported case of adipocytes among chorionic villi. Why foreign tissues show up in the placenta remains unknown; however, several new theories offer explanations.

Fetal Origin of Placental Hepatic Nodule

Intraplacental hepatic nodules are extremely rare and range from incidentally identified microscopic nodules to large mass-forming lesions. We describe the case of an incidentally identified intraparenchymal hepatic nodule in the placenta from a near-term delivery of a male infant at 36 weeks gestation. Lesional cells were positive for HepPar1, focally positive for glypican3, and negative for calretinin and alpha-fetoprotein, supportive of hepatocellular origin. Fluorescence in-situ hybridization and chromosomal microarray both showed a male sex chromosome complement (XY) within the nodule, confirming the fetal origin of this nodule. We provide the first report of the confirmed fetal origin of these rare lesions, lending support to the hypothesis that placental hepatic nodules may represent an embryonal rest or residua of abnormal cell migration.

Heterotopic Liver Nodule Compressing a Two-Vessel Umbilical Cord: An Unusual Cause of Intrauterine Fetal Demise

Heterotopic liver tissue in the umbilical cord is rare, and the outcome is quite unpredictable based on the few reported cases. We present a case of heterotopic liver nodule in the umbilical cord of a midtrimester fetus who died in utero. Although such association has only been reported once, heterotopic nodular tissue in the umbilical cord must be regarded as a potential cause of fetal demise by a mechanism analogous to the more common umbilical cord abnormalities resulting in umbilical vessel compromise.

Heterotopic Nodules in the Placenta, an Immunohistochemical Re-evaluation of the Diagnosis of Adrenocortical Heterotopia

BACKGROUND

Rare nodules of heterotopic adrenocortical and hepatic tissue are reported in the placenta. A mechanism for adrenocortical tissue in the placenta has been perplexing, while hepatic tissue is generally considered related to yolk sac primordia. The clear cell morphology of these nodules is similar to the adrenal cortex of the adult; however, the fetal adrenal gland does not usually display clear cells.

METHODS

We stained 9 placental nodules, histologically identical to "adrenocortical" heterotopia of the placenta, to determine whether adrenocortical differentiation could be confirmed. These cases include 3 archival cases initially diagnosed as "adrenocortical" heterotopia.

RESULTS

Immunohistochemical staining with steroid factor-1 (SF-1), HepPar-1, and Arginase-1 showed that these nodules of clear cells are actually hepatic (SF-1 negative, HepPar-1, and Arginase-1 positive). PAS staining suggests that glycogen accumulation is responsible for the clear cytoplasm. In contrast, a nodule of adrenocortical heterotopia near the testis and the adrenal gland from a 38-week-old neonatal autopsy case confirm SF-1 reactivity as expected.

CONCLUSION

We propose that adrenocortical heterotopia in the placenta is a misnomer, and that these subchorionic nodules of clear cells demonstrate hepatic differentiation.

Ectopic Fetal Hepatic Tissue in the Placenta

When an unusual intraplacental lesion is identified during pathologic examination, it becomes of substantial import to determine whether it represents a normal structure, metastasis from the mother, or a primary benign tumor, including those secondary to abnormal embryologic development versus a primary malignant placental tumor. In this case report, we identified an incidental nest of intraplacental cells with nondiagnostic morphology and negative initial Glypican-3 stain in a healthy 35-wk gestation. This negative result prompted a broadening of the differential before ultimately determining this lesion was indeed ectopic liver with positive Arginase-1 and HepPar-1 staining. This may represent the mature hepatocyte phenotype within the lesional cells of this near-term birth, a dichotomy not previously discussed in the literature, which focuses on the fetal hepatocyte phenotype, also rarely seen. In this report, we summarize the previous literature regarding intraplacental ectopic liver, and we propose a sensitive approach to suspected ectopic liver of the placenta that may be sufficient to capture both the fetal and mature hepatocyte immunophenotypes. This approach may extend to other related pathologies including assessment of suspected intraumbilical hepatocytes.

A first case of hepatocellular carcinoma in the baboon (Papio spp.) placenta

We present a case of hepatocellular carcinoma (HCC) in the placenta of healthy baboon (Papio spp.). Grossly, the fetal, maternal, and placental tissues were unremarkable. Histologically, the placenta contained an unencapsulated, poorly demarcated, infiltrative, solidly cellular neoplasm composed of cells that resembled hepatocytes. The neoplastic cells were diffusely positive for vimentin and focally positive for Ae1/Ae3, Arginase -1, glutamine synthetase, and CD10, and negative for ER, vascular markers (CD31 and D240), S100, glypican, C-reactive protein, FABP, desmin, and beta-catenin; INI1 positivity was similar to non-neoplastic tissues. The case likely represents a unique subtype of HCC.