Fetal suprarenal masses--assessing the complementary role of magnetic resonance and ultrasound for diagnosis

MR Imaging of the Fetal Genitourinary Tract

Fetal MR imaging overcomes many of the technical barriers of ultrasound and is an important diagnostic tool for fetal genitourinary (GU) anomalies. It is suited for evaluation of GU anomalies because of the fluid-sensitive sequences and superior soft tissue contrast. Often GU malformations are part of a multisystem genetic or congenital condition, and imaging the entire fetus with MR adds additional clarity about the extent of disease. It adds confidence to diagnoses of renal agenesis, urinary tract dilation, cystic disease, and tumors. It is particularly useful to delineate anatomy in complex GU malformations. This additional information guides counseling.

Magnetic resonance imaging of fetal abdominal pathology: a complementary tool to prenatal ultrasound

Fetal magnetic resonance imaging (MRI) is increasingly being used worldwide as a complementary tool to prenatal ultrasound (US) for multiple fetal pathologies. The aim of this article is to describe and illustrate how MRI can help US to evaluate fetal abdominal anomalies, based on cases performed in a tertiary public university hospital. Prenatal US, fetal MRI and postnatal imaging of these cases will be shown side-by-side to describe and illustrate the added value of fetal MRI in the different organs/systems and its impact on clinical management.

Prenatal presentation of an adrenocortical tumor

Background

Prenatally identified suprarenal masses are most often found to be adrenal hemorrhage. The most common tumor in this situation is neuroblastoma.

Case Presentation

We report the case of a rare adrenocortical tumor found prenatally on ultrasound. While most patients with adrenocortical tumors present with virilizing symptoms, our patient did not have evidence of virilization and was presumed to have neuroblastoma.

Conclusion

Following a period of observation, our patient underwent surgical resection due to tumor growth revealing the unexpected diagnosis.

Imaging modalities and management of prenatally diagnosed suprarenal masses: an updated literature review and the experience at a high volume Fetal Treatment Center

BACKGROUND/PURPOSE

The differential diagnosis for prenatal suprarenal masses (SRMs) is broad and includes neuroblastoma, adrenal hemorrhage, and subdiaphragmatic extralobar pulmonary sequestration (SEPS). We sought to elucidate the appropriate postnatal management for fetuses found to have an SRM.

METHODS

We conducted a retrospective review of patients prenatally diagnosed with SRM at our institution between 1998 and 2018. Prenatal characteristics, imaging, and neonatal outcomes were collected. We also performed a PubMed literature search and pooled analysis of all patients with a prenatally diagnosed SRM previously described in the literature.

RESULTS

The literature review yielded 32 studies, of which 19 were single case reports. In our case series, 12 patients were included. Seven patients were delivered vaginally, one was terminated. Postnatal diagnoses included: SEPS (n = 5), adrenal hemorrhage (n = 3), polycystic kidney (n = 2), splenic cyst (n = 1), and unknown for one patient. All but two of the final diagnoses had been on the initial diagnostic differential. With the exception of the terminated fetus, all remain alive today. On pooled analysis, patients who underwent operative management were diagnosed later 32 versus 24 weeks and had a significant predominance of left-sided lesions (59.5 versus 39.2%). The published literature demonstrates a trend toward observation versus resection over the past 30 years.

CONCLUSIONS

Patients prenatally diagnosed with an SRM have an excellent prognosis. Our series demonstrates a high incidence of SEPS, which were all resected, and adrenal hemorrhage, which were observed with repeat imaging. These patients can be followed with serial postnatal ultrasounds to determine the diagnosis prior to deciding the appropriate treatment.

Prenatal diagnosis of abdominal lymphatic malformations

Abdominal lymphatic malformations (LM) are rare congenital malformations of the lymphatic system, representing only 2% of all LM in newborns. They may arise from intra-abdominal solid organs (such as the liver, pancreas, kidneys, spleen, adrenal glands, and gastrointestinal tract), mesentery, omentum, and retroperitoneum. Mesenteric LM are the most commonly seen, with retroperitoneal LM being the second most common. Fetal abdominal LM could be associated with karyotypic or other abnormalities, including skin edema, hydrops fetalis, and polyhydramnios, and prenatal diagnosis and perinatal counseling for these LM are important. Prenatal ultrasound (US) and magnetic resonance imaging (MRI) have led to an increased diagnosis of abdominal LM and improved monitoring and intervention postnatally. This article provides an overview of fetal abdominal LM, including the prenatal diagnoses, differential diagnoses, comprehensive illustrations of the imaging findings, treatments, and fetal outcomes.

Prenatal Assessment of Atypical Adrenal Glands: A Systematic Approach for Diagnosis

The aim of this study was to identify specific unusual prenatal ultrasound (US) patterns of the adrenal gland and to propose a systematic approach for diagnosis. Six fetuses with unusual aspects of one or both adrenal glands, detected during routine prenatal US screening, were evaluated. Prenatal and postnatal management are described. A checklist of US features was created to perform a detailed analysis of adrenal lesions and guide prenatal management; this includes the time of appearance, location, growth, vascularization, structure, and presence of findings suggestive of malignancy.

Prenatal Imaging Diagnosis of Suprarenal Lesions

INTRODUCTION

Prenatal suprarenal lesions represent diverse pathologies. This study investigated prenatal imaging features and regression patterns associated with specific lesion diagnoses.

METHODS

This is a multicenter retrospective review of fetuses with prenatally diagnosed suprarenal lesions between 2001 and 2019. Prenatal ultrasound and MRI characteristics, postnatal imaging, and clinical course were reviewed. Prenatal imaging findings were compared by the most common diagnoses and regression patterns.

RESULTS

Forty-four fetuses were prenatally diagnosed with suprarenal lesions. Diagnoses included pulmonary sequestration (n = 12; 27.3%), adrenal hemorrhage (n = 12; 27.3%), upper quadrant cyst (including 2 duplication cysts, 1 splenic cyst, and 3 indeterminate cysts), neuroblastoma (n = 4), adrenal hyperplasia (n = 3), bilateral adrenal calcifications (n = 1), and indeterminate lesions (n = 6). Sequestrations were uniformly left-sided (100 vs. 50%; p = 0.014) and diagnosed earlier in gestation than adrenal hemorrhages (p = 0.025). Sequestrations were also significantly more likely to have a prenatal feeding vessel (p = 0.005), low T1 MRI signal (p = 0.015), and no MRI blood products (p = 0.018) compared to adrenal hemorrhages. When comparing all 44 patients, a prenatal feeding vessel and low T1 signal on prenatal MRI were significantly associated with lesion persistence (p = 0.003; p = 0.044).

DISCUSSION/CONCLUSION

Imaging findings on prenatal ultrasound and MRI aid in the diagnosis of suprarenal lesions, including differentiating pulmonary sequestrations and adrenal hemorrhages.

Neonatal Neuroblastoma

Neuroblastoma accounts for approximately 8% of all pediatric cancers, with 5% diagnosed during the neonatal period. Despite the disproportionate contribution of neuroblastoma to childhood cancer deaths, neonatal neuroblastoma has a favorable prognosis, often with little or no therapy required. Therefore, minimizing therapy and mitigating complications/toxicities are emphasized, including using a watch-and-wait approach for patients at low risk for disease progression/relapse. However, stage MS neuroblastoma exhibits a unique pattern of disseminated disease, can be challenging to manage, and may require early intervention with systemic chemotherapy. In this review, the epidemiology, treatment options, and anticipated outcomes for neonatal neuroblastoma are discussed.

Imaging of solid congenital abdominal masses: a review of the literature and practical approach to image interpretation

Fetal abdominal tumors are rare, usually benign, and cause a great deal of anxiety for expectant parents and the physicians counseling them. In this paper the author reviews the most common fetal abdominal tumors in the liver (hemangioma, mesenchymal hamartoma, hepatoblastoma, metastases) and the kidney (congenital mesoblastic nephroma, Wilms tumor, malignant rhabdoid tumor, and clear cell sarcoma), and suprarenal mass lesions (adrenal neuroblastoma, adrenal hemorrhage, and subdiaphragmatic extralobar pulmonary sequestration). The author describes the imaging approach, imaging appearance and differentiating features of tumors, and differences between fetal and childhood appearances of tumors.

Normal size of the fetal adrenal gland on prenatal magnetic resonance imaging

BACKGROUND

The adrenal gland plays a vital role in fetal growth. Many disease states such as congenital adrenal hyperplasia, hemorrhage and tumors can lead to morphological changes in the gland. Ultrasound measurements of normal adrenal sizes in the fetus reported in the literature have shown a trend of increasing size with gestational age. There is no literature available on standard fetal adrenal sizes or detailed appearance by fetal MRI.

OBJECTIVE

The purpose of this study was to provide MR data on the size and signal characteristics of the fetal adrenal gland throughout the second and third trimesters.

MATERIALS AND METHODS

In this retrospective review, we selected 185 prenatal MRIs obtained from Jan. 1, 2014, to May 31, 2017, with normal abdominal findings for inclusion. The adrenal glands were identified in coronal, sagittal or axial T2-W planes and coronal T1-W plane when available. We measured the length and thickness of the medial and lateral limbs of the right and left adrenal glands and recorded signal intensity on T1-W and T2-W sequences, gender and gestational age in each case.

RESULTS

The gestational age (GA) ranged 18-37 weeks. Visibility of the adrenal glands on T2-W images was high (90.3-97.2%) up to 30 weeks of GA but declined afterward (47.5-62.2% at 31-37 weeks). Visibility on T1-W images increased with GA, ranging from 21.4% visibility at 18-22 weeks and increasing to 40% at 35-37 weeks. Mean lengths of the adrenal gland limbs steadily increased from 8.2 mm at 18-22 weeks to 11.0 mm at 35-37 weeks. In the second trimester, adrenal glands were low in signal intensity on T2-W images and were surrounded by hyperintense perirenal fatty tissue. In the third trimester, the glands became less distinct, with increasing signal and obliteration of perirenal tissue. The glands were moderately hyperintense on T1-W images throughout pregnancy, with increasing visibility as pregnancy progressed.

CONCLUSION

Normal sizes and signal intensities for adrenal glands are reported. Visibility of adrenal glands on T2-W images was 90.3-97.2% up to 30 weeks but declined thereafter. Visibility on T1-W images increased in the third trimester. Adrenal gland sizes increased with gestational age.

Prenatal diagnosis of suprarenal mass by magnetic resonance imaging: a case series

Objective: The aim of this study was to evaluate the perinatal outcomes and postnatal follow-up of prenatally diagnosed suprarenal masses (SRMs) evaluated by magnetic resonance imaging (MRI). Methods: Thirteen fetuses with SRMs detected during routine prenatal ultrasound screening were evaluated by MRI between February 2007 and May 2015. The prenatal characteristics of the masses, complications of the pregnancies, and related malformations were collected as the postnatal clinical, radiological, and pathological data. Results: The median gestational age at MRI was 30 weeks (18-41), and birth weight was 3285 (1700-3750) g. The mean follow-up period was 6 years (1.3-10). We observed 69.2% of the masses, which were predominantly cystic (69.2%), located on the left side. Associated malformations were found in 23% of the fetuses, with congenital heart defects being more prevalent. During the pregnancy, 15.4% of the fetuses had involution of the SRM, and one fetus had surgical treatment and different ultrasound and MRI diagnoses. Of the 69.2% of the cases, spontaneous resolution occurred in 30.7% during the first year of life and 38.4% the masses presented without modifications or signs of regression since the neonatal period. Conclusions: Prenatal SRMs were associated with congenital heart defects. Spontaneous regression and absence of modifications in the masses were commonly observed in the long-term follow-up of the SRMs.

Highlights on MRI of the fetal body

Fetal MRI is a level III diagnostic tool performed subsequently a level II prenatal ultrasound (US), in cases of inconclusive ultrasonographic diagnosis or when a further investigation is required to confirm or improve the diagnosis, to plan an appropriate pregnancy management. Fetal MRI plays an increasingly important role in the prenatal diagnosis of fetal neck, chest and abdominal malformations, even if its role has been amply demonstrated, especially, in the field of fetal CNS anomalies. Due to its multiparametricity and multiplanarity, MRI provides a detailed evaluation of the whole fetal respiratory, gastrointestinal and genitourinary systems, especially on T2-weighted (W) images, with a good tissue contrast resolution. In the evaluation of the digestive tract, T1-W sequences are very important in relation to the typical hyperintensity of the large intestine, due to the presence of meconium. The objective of this review is to focus on the application of fetal MRI in neck, chest and abdominal diseases.

Diagnosis of neonatal neuroblastoma with postmortem magnetic resonance imaging

Postmortem magnetic resonance imaging (MRI) is emerging as a valuable tool to accompany traditional autopsy and has potential for use in cases when traditional autopsy is not possible. This case report will review the use of postmortem MRI with limited tissue sampling to differentiate between metastatic neuroblastoma and hepatoblastoma which could not be clearly differentiated with prenatal ultrasound, prenatal MRI, or emergent postnatal ultrasound. The mother presented to our institution at 27 weeks gestation after an obstetric ultrasound at her obstetrician's office identified a large abdominal mass. Fetal ultrasonography and MRI confirmed the mass but were unable to differentiate between neuroblastoma and multifocal hepatoblastoma. The baby was delivered by cesarean section after nonreassuring heart tones led to an emergent cesarean section. The baby underwent decompressive laparotomy to relieve an abdominal compartment syndrome; however, the family eventually decided to withdraw life support. At this time, we performed a whole body postmortem MRI which further characterized the mass as an adrenal neuroblastoma which was confirmed with limited tissue sampling. Postmortem MRI was especially helpful in this case, as the patient’s family declined traditional autopsy.