DOI: 10.1148/rg.274065207
RadioGraphics 2007;27:1187-1190
Best Cases from the AFIP
Placental Chorioangioma1
Aaron D. Kirkpatrick, MD,
Daniel J. Podberesky, MD,
Anne E. Gray, MD, and
Joseph H. McDermott, MD
1 From the Departments of Radiology (A.D.K., D.J.P.), Obstetrics and Gynecology (A.E.G.), and Pathology (J.H.M.), Wilford Hall Medical Center, 2200 Bergquist Dr, Lackland AFB, TX 78236-9908. Received December 21, 2006; revision requested February 7, 2007, and received March 16; accepted March 21. All authors have no financial relationships to disclose.
Address correspondence to A.D.K. (e-mail: akirkpatrick{at}mac.com).
 |
History
|
|---|
A 29-year-old gravida 3, para 2 woman was referred to maternal fetal medicine for clinical follow-up and serial ultrasonographic (US) surveillance. The patient had an unremarkable prenatal course until a placental mass was noted at a routine second trimester obstetric US examination. Given its imaging characteristics, the mass was thought to be most consistent with a chorioangioma. The remainder of the pregnancy passed without complications, and at 39 weeks the patient underwent an elective induction with intravenous oxytocin (Pitocin; Parke-Davis, New York, NY).
|
Imaging Findings
|
|---|
Routine obstetric US images demonstrated a 4.3 x 3.8 x 3.0-cm hypoechoic, circumscribed, ovoid intraplacental mass containing small anechoic spaces that protruded into the amniotic cavity (Fig 1). Power Doppler images demonstrated flow within the anechoic spaces and proximity of the mass to the placental cord insertion (Figs 2, 3).
View larger version (174K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 1. Routine gray-scale US image, obtained during the third trimester to monitor progression of known chorioangioma, shows a 4.3 x 3.8 x 3.0-cm circumscribed hypoechoic intraplacental mass with a few anechoic regions. The mass protrudes from the fetal surface of the placenta into the amniotic cavity.
|
|
View larger version (95K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 2. Power Doppler US image of the intraplacental mass (chorioangioma) demonstrates flow within previously noted anechoic spaces. This finding helps to differentiate the mass from other intraplacental tumors such as hematoma.
|
|
|
Pathologic Evaluation
|
|---|
After an uncomplicated vaginal delivery, the placenta was delivered intact and submitted for histologic evaluation (Fig 4). The placenta (535 g, 18.3 x 17.2 x 1.2 cm) was ovoid with an eccentrically placed three-vessel umbilical cord. A single 4.0 x 3.5 x 3.5-cm well-circumscribed, roughly spherical, red mass was present within the central portion of the placenta adjacent to the cord insertion, spanning nearly the entire width of the placental disk and extending through the maternal surface. The mass was separate from the placenta, with a small cleft present around the majority of the mass. Cut sections of the mass revealed a slightly variegated red-brown cut surface (Fig 5a) with a single 2.0 x 2.0 x 0.5-cm yellow-white area at one edge and multiple small, grossly visible vascular lumina centrally. Histologic analysis revealed that the mass consisted of a dense proliferation of capillaries within a collagenous stroma (Fig 5b).
View larger version (187K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 4. Photograph of the gross specimen of the placenta, immediately after placental delivery, shows the circumscribed ovoid mass protruding from the placental surface near the cord insertion.
|
|
View larger version (50K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 5a. Chorioangioma. (a) Photograph of a cross section of the central placental disk shows the mass (arrow) and adjacent placenta. (b) Photomicrograph (original magnification, x200; hematoxylin-eosin stain) of a cut section of the mass demonstrates a proliferation of capillaries within a background of increased collagen.
|
|
View larger version (194K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 5b. Chorioangioma. (a) Photograph of a cross section of the central placental disk shows the mass (arrow) and adjacent placenta. (b) Photomicrograph (original magnification, x200; hematoxylineosin stain) of a cut section of the mass demonstrates a proliferation of capillaries within a background of increased collagen.
|
|
|
Discussion
|
|---|
Chorioangioma, originally described by Clarke in 1798, is the most common tumor of the placenta, with reported prevalence of approximately 0.5%–1.0% (1). Most chorioangiomas are small and are found incidentally at screening obstetric US examinations. The true prevalence of this tumor is likely unknown because many are thought to be undetectable without careful sectioning of the placenta as most chorioangiomas are minute and singular (2). In fact, in one clinical series of 136 chorioangiomas, more than half of all tumors were discovered by using only histologic techniques (2). Most authors categorize chorioangiomas as neoplasms. However, there is some debate as to whether they are actually hamartomas, given their composition of mostly native placental tissue and their inability to metastasize (2–5). Chorioangiomas have no malignant potential (3–6). Three histologic types of chorioangiomas have been described: angiomatous (capillary), cellular, and degenerative, with angiomatous as the most common type (4,7,8). Chorioangioma should be considered as a rare entity in the differential diagnosis of an elevated level of maternal 
-fetoprotein in the serum (3).
Large (
5-cm) or multiple chorioangiomas have been reported to occur at a rate of 1:3500 to 1:16,000 births (9). Although most chorioangiomas are asymptomatic, large or multiple chorioangiomas have a dismal prognosis due to their high association with maternal and fetal complications (ranging from 30% to 50%), which include polyhydramnios, preterm labor, fetal hemolytic anemia, fetal thrombocytopenia, cardiomegaly, intrauterine growth restriction, toxemia, placental abruption, preeclampsia, and congenital abnormalities (2,7–12). This complication rate may be exaggerated due to a bias in reporting larger chorioangiomas, however, given their increased association with complications and the relative ease of missing tiny, clinically insignificant tumors (11). One retrospective case series reported a statistically significant increased incidence of preterm labor associated with chorioangiomas when compared with a control group of patients with normal placentas; however, it is unclear if the preterm labor was caused by chorioangioma or polyhydramnios, which commonly occurs in the setting of this tumor (10).
The pathophysiology of maternal and fetal complications is not well understood. Theories for polyhydramnios include (a) transudation of fluid caused by a mechanical obstruction of blood flow by the tumor near the cord insertion, (b) increased transudation of fluid through a large vascular surface area, and (c) functional insufficiency of the placenta secondary to bypassing fetal circulation via shunt mechanism into the tumor vascular bed (8). Fetal cardiomegaly is also a potential complication and is thought to occur secondary to high cardiac output from arteriovenous shunting, with resultant left-to-right shunt or chronic hypoxia from unoxygenated blood that bypasses maternal circulation through the tumor vascular bed (8).
At gray-scale US examination, chorioangioma is a hypo- or hyperechoic circumscribed mass that is distinctly different from the placenta and contains anechoic cystic areas (6,12,13). Large lesions may or may not contain fibrous septa, which create the appearance of a complex mass (12,13). The tumor classically protrudes into the amniotic cavity from the fetal surface near the cord insertion. On color Doppler images, the anechoic cystic areas demonstrate pulsatile flow on spectral analysis, a finding consistent with vascular channels within the tumor (12). Bromley and Benacerraf (14) demonstrated the necessity of color Doppler imaging for antenatal diagnosis of chorioangioma, by describing 10 examples of solid placental masses for which gray-scale imaging alone did not allow chorioangioma to be differentiated from placental hematoma. However, color Doppler imaging can demonstrate blood flow within the lesion, a finding that distinguishes chorioangioma from a placental hematoma (12).
The differential diagnosis of placental tumors includes partial hydatidiform mole, placental hematoma (intraplacental or subchorionic), teratoma, metastases, and leiomyoma (1,13). Again, the use of color Doppler imaging can confirm the presence of vascular channels in the tumor contiguous with the fetal circulation, findings that exclude degenerative leiomyoma, teratoma, and incomplete hydatidiform mole (12). In cases for which US findings are equivocal for chorioangioma, magnetic resonance (MR) imaging is a potential problem-solving modality reported in the literature. MR imaging findings for chorioangioma include a heterogeneous mass with high T2 signal intensity, an appearance similar to that of a hemangioma. However, the tumor can demonstrate heterogeneous signal intensity if it undergoes acute infarction and degenerative changes. There are no studies to demonstrate the sensitivity and specificity of MR imaging in distinguishing chorioangioma from other placental lesions or if MR imaging can reveal smaller lesions than can US (8).
Color Doppler imaging can also provide prognostic information for large chorioangiomas. Large chorioangiomas may undergo spontaneous infarction with decreased echogenicity, decreased tumor volume, and decreased blood flow on color Doppler images (7,12). There are reports of pathologically proved infarction without typical US changes, but these cases demonstrate decreased vascular density at three-dimensional color Doppler evaluation (15). Chorioangiomas with decreased blood flow have generally demonstrated improved fetal hemodynamics with improved clinical outcomes. There are case reports of spontaneous infarction with regression of large chorioangiomas and improved fetal hydrops (16).
Although US evaluation with color flow imaging is usually accurate in differentiating chorioangiomas from other placental masses, some degenerating chorioangiomas can be mistaken for placental hematomas due to a lack of demonstrable blood flow (12).
Chorioangioma is usually treated with expectant management, as the majority of tumors are asymptomatic. Small tumors are usually monitored with US every 6–8 weeks, whereas large tumors require serial US examinations every 1–2 weeks (3). In situations in which maternal or fetal complications necessitate intervention, there are several possible treatments. However, most of these cases have a dismal prognosis (12). Possible interventions include serial fetal transfusions, fetoscopic laser coagulation of vessels supplying the tumor, chemosclerosis with absolute alcohol, and endoscopic surgical devascularization (5,12,17).
The patient presented in this case was asymptomatic, and thus expectant management was pursued. Mother and newborn both did well with uncomplicated scheduled induction.
|
Footnotes
|
|---|
The opinions and assertions contained herein are the private views of the authors and are not to be construed as official nor as reflecting the views of the Departments of the Air Force, Navy, Army, or Defense.
Editor’s Note.—Everyone who has taken the course in radiologic pathology at the Armed Forces Institute of Pathology (AFIP) remembers bringing beautifully illustrated cases for accession to the Institute. In recent years, the staff of the Department of Radiologic Pathology has judged the "best cases" by organ system, and recognition is given to the winners on the last day of the class. With each issue of RadioGraphics, one or more of these cases are published, written by the winning resident. Radiologic-pathologic correlation is emphasized, and the causes of the imaging signs of various diseases are illustrated.
|
References
|
|---|
- Jauniaux E, Campbell S. Ultrasonographic assessment of placental abnormalities. Am J Obstet Gynecol 1990;163(suppl 5, pt 1):1650–1658.[Medline]
- Guschmann M, Henrich W, Entezami M, Dudenhausen JW. Chorioangioma: new insights into a well-known problem. J Perinat Med 2003;31(2): 163–169.[CrossRef][Medline]
- Harris RD, Cho C, Wells WA. Sonography of the placenta with emphasis on pathological correlation. Semin Ultrasound CT MR 1996;17(1): 66–89.[CrossRef][Medline]
- Wehrens X, Offermans J, Snijders M, Peeters L. Fetal cardiovascular response to large placental chorioangioma. J Perinat Med 2004;32(2):107–112.[CrossRef][Medline]
- Wanapirak C, Tongsong T, Sirichotiyakul S, Chanprapaph P. Alcoholization: the choice of intrauterine treatment for chorioangioma. J Obstet Gynaecol Res 2002;28(2):71–75.[CrossRef][Medline]
- Polat P, Suma S, Kantarcy M, Alper F, Levent A. Color Doppler US in the evaluation of uterine vascular abnormalities. RadioGraphics 2002;22: 47–53.[Abstract/Free Full Text]
- Napolitano R, Maruotti G, Mazzarelli L, Quaglia F, Tessitore GP. Prenatal diagnosis of placental chorioangioma: our experience. Minerva Ginecol 2005;57:649–654.[Medline]
- Mochizuki T, Nishiguchi T, Ito I, et al. Case report of antenatal diagnosis of chorioangioma of the placenta: MR features. J Comput Assist Tomogr 1996;20(3):413–416.[CrossRef][Medline]
- Esen UI, Orife SU, Pollard K. Placental chorioangioma: a case report and literature review. Br J Clin Pract 1997;51(3):181–182.[Medline]
- Bashiri A, Furman B, Erez O, Wiznitzer A, Holcberg G, Mazor M. Twelve cases of placental chorioangioma: pregnancy outcome and clinical significance. Arch Gynecol Obstet 2002;266(1): 53–55.[CrossRef][Medline]
- Sepulveda W, Alcalde JL, Schnapp C, Bravo M. Perinatal outcome after prenatal diagnosis of placental chorioangioma. Obstet Gynecol 2003;102 (suppl 5, pt 1):1028–1033.[Abstract/Free Full Text]
- Zalel Y, Weisz B, Ronni G, Schiff E, Shalmon B, Achiron R. Chorioangiomas of the placenta: sonographic and Doppler flow characteristics. J Ultrasound Med 2002;21(8):909–913.[Abstract/Free Full Text]
- Harris RD, Barth RA. Sonography of the gravid uterus and placenta: current concepts. AJR Am J Roentgenol 1993;160:455–465.[Abstract/Free Full Text]
- Bromley B, Benacerraf BR. Solid masses on the fetal surface of the placenta: differential diagnosis and clinical outcome. J Ultrasound Med 1994; 13(11):883–886.[Abstract]
- Hata T, Kanenishi K, Inubashiri E, et al. Three-dimensional sonographic features of placental abnormalities. Gynecol Obstet Invest 2004;57(2): 61–65.[CrossRef][Medline]
- Chazotte C, Girz B, Koenigsberg M, Cohen W. Spontaneous infarction of placental chorioangioma and associated regression of hydrops fetalis. Am J Obstet Gynecol 1990;163(suppl 4, pt 1): 1180–1181.[Medline]
- Quintero RA, Reich H, Romero R, Johnson MP, Goncalves L, Evans MI. In utero endoscopic devascularization of a large chorioangioma. Ultrasound Obstet Gynecol 1996;8(1):48–52.[CrossRef][Medline]
Top
History
Imaging Findings
