Contribution of magnetic resonance imaging to the prenatal diagnosis of common congenital vascular anomalies

BACKGROUND

Screening ultrasound (US) has increased the detection of congenital vascular anomalies in utero. Complementary magnetic resonance imaging (MRI) may improve the diagnosis, but its real utility is still not well established.

OBJECTIVES

We aimed to describe the imaging findings on prenatal US and MRI of the most frequent congenital vascular anomalies (lymphatic malformations and congenital hemangiomas) to assess the accuracy of prenatal US and MRI exams for diagnosis and to evaluate the relevance of the additional information obtained by complementary fetal MRI.

MATERIALS AND METHODS

All confirmed postnatal congenital vascular anomalies detected in the last 10 years at 3 university hospitals were retrospectively identified. The prenatal diagnosis was compared with the final diagnosis for both methods and the clinical relevance of additional MRI information was evaluated. A second MRI in advanced pregnancy was performed in fetuses with lesions in a sensitive anatomical location and the clinical relevance of the additional information was evaluated.

RESULTS

Twenty-four cases were included in the study, 20 lymphatic malformations and 4 hemangiomas. MRI slightly improved the diagnosis of lymphatic malformation, 85% vs. 80% at US, especially for abdominal lesions. Both methods had a low identification rate (25%) for tumors. MRI performed late in five fetuses with lymphatic malformation allowed optimized management at birth.

CONCLUSION

MRI improves the diagnosis of congenital lymphatic malformations whereas hemangiomas remain difficult to identify in utero. The main role of MRI is to provide high-defined anatomical data to guide management at birth.

Complete involution of prenatally-diagnosed fetal scalp hemangioma

OBJECTIVE

Scalp hemangioma is a rare benign fetal tumor. Here, we describe the detailed imaging features and natural course of a fetal scalp hemangioma until 1 year of age.

CASE REPORT

We encountered a case of scalp hemangioma at 23 weeks' gestation by prenatal ultrasonography and magnetic resonance imaging. The mass persisted postnatally, but spontaneously regressed after birth.

CONCLUSION

Proper diagnosis with prenatal ultrasonography and magnetic resonance imaging is important when a scalp mass is suspected in utero. Continuation of the pregnancy after appropriate counseling is prudent, considering the favorable prognosis and the rate of spontaneous regression of uncomplicated cases.

Vascular and perivascular lesions of skin and soft tissues in children and adolescents

Vascular anomalies in children and adolescents are the most common soft tissue lesions and include reactive, malformative, and neoplastic tumefactions, with a full spectrum of benign, intermediate, and malignant neoplasms. These lesions are diagnostically challenging because of morphologic complexity and recent changes in classification systems, some of which are based on clinical features and others on pathologic findings. In recent decades, there have been significant advances in clinical diagnosis, development of new therapies, and a better understanding of the genetic aspects of vascular biology and syndromes that include unusual vascular proliferations. Most vascular lesions in children and adolescents are benign, although the intermediate locally aggressive and intermediate rarely metastasizing neoplasms are important to distinguish from benign and malignant mimics. Morphologic recognition of a vasoproliferative lesion is straightforward in most instances, and conventional morphology remains the cornerstone for a specific diagnosis. However, pathologic examination is enhanced by adjunctive techniques, especially immunohistochemistry to characterize the type of vessels involved. Multifocality may cause some uncertainty regarding the assignment of "benign" or "malignant." However, increased interest in vascular anomalies, clinical expertise, and imaging technology have contributed greatly to our understanding of these disorders to the extent that in most vascular malformations and in many tumors, a diagnosis is made clinically and biopsy is not required for diagnosis. The importance of close collaboration between the clinical team and the pathologist cannot be overemphasized. For some lesions, a diagnosis is not possible from evaluation of histopathology alone, and in a subset of these, a specific diagnosis may not be possible even after all assembled data have been reviewed. In such instances, a consensus diagnosis in conjunction with clinical colleagues guides therapy. The purpose of this review is to delineate the clinicopathologic features of vascular lesions in children and adolescents with an emphasis on their unique aspects, use of diagnostic adjuncts, and differential diagnosis.

Rapidly involuting congenital hemangioma: a case of complete prenatal involution

We report a case of rapidly involuting congenital hemangioma of the flank, which was diagnosed in the 2(nd) trimester of gestation and showed complete involution before term. In our case sonography revealed a highly vascular soft tissue mass with smooth contours, which was isointense with the placenta on T2-weighted MR images. The fetus was born with scar tissue at the site of the lesion. To our knowledge this is the 1(st) reported case of rapidly involuting congenital hemangioma showing complete involution before term.