The Importance of Sonography in the Evaluation of Neonatal Adrenal Hemorrhage

Transcription

1 JDMS 25: July/August The Importance of Sonography in the Evaluation of Neonatal Adrenal Hemorrhage RINI-SULTANA VALDESPINO, BA, AS, RDMS From Orange Coast College, School of Allied Health Professions, Diagnostic Medical Sonography Division, Costa Mesa, California; University of California at Irvine Medical Center, Department of Radiology, Ultrasound Division, Orange, California; Kaiser Permanente Riverside Medical Center, Department of Radiology, Ultrasound Division, Riverside, California. Correspondence: DOI: / Neonatal adrenal hemorrhage is a relatively common condition of the newborn. Etiologies of neonatal adrenal hemorrhage include maternal/ fetal stress, birth trauma, congenital syphilis, dehydration, anoxia, or other systemic disorders. Clinical presentation ranges from asymptomatic to anemia, hypotension, vomiting, jaundice/hyperbilirubinemia, scrotal discoloration, hyponatremia, and palpable abdominal mass. Adrenal hemorrhage sonographically appears as an abdominal mass with displacement of the kidney inferiorly, known as mass effect. Differentiation of adrenal hemorrhage from more serious pathologies such as adrenal carcinoma, neuroblastoma, or pheochromocytoma is critical. Bluish discoloration of the scrotum may also occur due to extravasation of blood from the hemorrhage, leading to an incorrect diagnosis of testicular torsion or acute scrotum. Proper sonographic evaluation conservatively avoids unnecessary surgical exploration. Power Doppler imaging, color Doppler imaging, and serial gray-scale sonography can document the characteristics and progression of the condition for accurate diagnosis. Sonography is a preferred noninvasive screening modality for evaluating abdominal masses within the pediatric population because of its sensitivity, avoidance of radiation and sedation, and potential value for avoiding exploratory surgery. Key words: neonatal adrenal hemorrhage, mass effect, serial sonography, serial imaging, power Doppler imaging, color Doppler imaging The finding of adrenal hemorrhages in the neonate is not uncommon. Incidence based on postmortem studies is reported to be approximately 1.7

2 222 JOURNAL OF DIAGNOSTIC MEDICAL SONOGRAPHY July/August 2009 VOL. 25, NO. 4 per 1000 births. 1 Serial sonography, including the use of color Doppler and power Doppler, provides a unique opportunity to correctly differentiate hemorrhagic pathology from more serious abdominal masses such as adrenal carcinoma, neuroblastoma, or pheochromocytoma or distinguish between adrenal hemorrhage and acute scrotum, a diagnosis critical to avoiding unnecessary exploratory surgery. A case of a 10-day-old newborn with bilateral adrenal hemorrhages is presented. Case Report A 10-day-old newborn was referred for an abdominal sonogram because of a previous report of an abnormal renal sonogram performed at an outside hospital. Sonographic imaging of the left and right kidneys was performed with additional imaging of the upper abdomen and liver area, using an ATL HDI 5000 (Bothell, Washington) with a C 8-5 transducer. Sonographic findings revealed bilateral large adrenal hematomas. The right adrenal gland measured cm, with mixed echogenicity and an area of lower echogenicity, suggesting the presence of active bleeding. The left adrenal gland evidenced hemorrhage as well, with measures of cm. Both left and right adrenal glands produced mass effect on the kidneys. The right kidney measured cm and evidenced mild pelviectasis. The left kidney measured cm and evidenced moderate renal pelvis dilatation. A genitourinary voiding cystourethrogram with contrast revealed normal bladder anatomy, no reflux or extravasation, and, in postvoid views, the bladder emptied completely with no residual. Magnetic resonance imaging (MRI) without contrast confirmed bilateral adrenal hemorrhages with mass effect on the bilateral kidneys and the spleen. Renal function nuclear medicine imaging with administration of radiotracer, at patient age of 14 days, was performed to evaluate for causes of hyponatremia. Limited radiotracer uptake was noted in a triangular area superior to both kidneys, suggesting that the persistence of hyponatremia may be due to adrenal insufficiency induced by the hemorrhages. Subsequent data are unavailable as the patient was released from the hospital to be followed by the physician on an outpatient basis. Discussion The etiology of neonatal adrenal hemorrhage may be associated with traumatic birth, large size of newborn, maternal or fetal stress, hypoxia during delivery, septicemia, congenital syphilis, or colagulopathic disorders such as hemophilia. Clinical presentation can range from asymptomatic to anemia, hypotension, vomiting, jaundice (hyperbilirubinemia), scrotal discoloration, hyponatremia, palpable abdominal mass, and the appearance of abdominal calcifications. Differential diagnoses for adrenal hemorrhage should include adrenal and renal cystic disease, adrenal carcinoma, hyperbilirubinemia, hydronephrosis, neuroblastoma, pheochromocytoma, testicular torsion, or acute scrotum. The adrenal gland is triangular shaped and located superior to the upper pole of each kidney in the retroperitoneum. When normal and healthy, adrenal glands are more easily seen in neonates than in older infants and young children and are very difficult to see in adults. Sonographically, the healthy adrenal gland will appear as an inverted V or Y shape in the sagittal plane (Figure 1) and will appear curvilinear in shape in the transverse plane. In addition, the adrenal medulla will appear as an echogenic line surrounded by a hypoechoic adrenal cortex. The adrenal glands are especially vulnerable to hemorrhage due to birth trauma because of their size (approximately 20 times the relative size in the adult) and high vascularity with supply from the inferior phrenic artery, abdominal aorta, and renal artery. 2 Adrenal hemorrhage involvement of the right side is more common than the left side, is bilateral in 10% to 15% of cases, and is presumed to be secondary to compression of the adrenal gland between the liver and the spine. 3 The right adrenal vein is of shorter length because of its proximity to the inferior vena cava (IVC); its compression between the liver and spine increases venous pressure within the adrenal gland, subsequently inducing hemorrhage. Sonographically, the adrenal hemorrhage can appear as an oval heterogeneous mass located either within the Morrison s pouch (Figures 2 and 3) or the spleen/left kidney interface (Figure 4). When an adrenal hemorrhage occurs, it will be visualized superior to the upper pole of the kidney in the

3 EVALUATING NEONATAL ADRENAL HEMORRHAGE / Valdespino 223 FIGure 1. Normal neonatal adrenal gland. Sagittal view of a normal neonatal right adrenal gland demonstrating appearance as an inverted V or Y shape. FIGure 3. Mass effect. Sagittal view of neonatal right kidney and adrenal gland (Morrison s pouch). With adrenal hemorrhage, the adrenal glands will appear as a large heterogeneous solid mass or a mass of varying echogenicities. Inferior displacement of the kidney and mild pelviectasis due to mass effect are evidenced. FIGure 2. Neonatal adrenal hemorrhage. Transverse view of the neonatal right kidney and adrenal gland (AG), evidencing hemorrhage and mass effect on the kidney. Adrenal gland exhibits areas of various echogenicities, which demonstrates possible active bleeding, or the process of lysis and resolution of the hemorrhage. sagittal plane and medial to the kidney in the transverse plane. The hemorrhage, as a mass or enlargement, has the potential of displacing the kidney inferiorly while also pressing against the organ superior to the kidney, such as the liver or spleen. This displacement is known as mass effect. Mass effect can lead to further complications such as pelviectasis (Figure 3), hydronephrosis of the kidneys, or disorders of the surrounding organs instigated by the pressure or impingement from the mass. The sonographic appearance of neonatal adrenal hemorrhage is dependent on the age and degree FIGure 4. Avascularity of adrenal mass. Transverse view of neonatal left adrenal gland at left kidney/splenic interface. Evidence of avascularity of adrenal hemorrhage will differentiate this mass from more serious conditions such as neuroblastoma. of the process of the hemorrhage. Active adrenal bleeding appears sonolucent. Later on, a solid clot with a diffuse echogenicity is found. Next, liquefaction or lysis occurs and the mass demonstrates a mixed echogenicity often with a central hypoechoic region. Eventually, the mass becomes completely anechoic. 2 Complete resolution of the hemorrhage will appear as a residual echogenic calcification. Adrenal hemorrhage will appear avascular in contradiction to highly vascular malignancies. The use of color Doppler and power Doppler imaging

4 224 JOURNAL OF DIAGNOSTIC MEDICAL SONOGRAPHY July/August 2009 VOL. 25, NO. 4 provides valuable diagnostic information. Neuroblastoma, the most common solid malignant tumor in infancy and childhood, is a suprarenal solid tumor with small cysts and good perfusion, which demonstrates a sharp contrast to nonperfused adrenal hemorrhage. 4 Power Doppler imaging is independent of angle and direction of flow and able to display extremely low tissue perfusion states, effective in the differential diagnosis using the vascularity of the mass. 5 If the tumor is not vascularized and there is a lack of documented blood flow even though low flow settings have been chosen, one should suspect adrenal hemorrhage rather than tumor (Figure 3). 4 In addition, the location of suprarenal arteries as followed from their origins will also differentiate hemorrhage from malignant tumor. Serial sonography of the area allows for differentiation between neonatal adrenal hemorrhage and masses of more serious implications. Adrenal hemorrhage will progress to resolution, and unnecessary surgery would have been avoided, whereas suspect masses such as neuroblastoma may persist or enlarge over the period of serial sonography, raising suspicion of malignancy and prompting subsequent surgical exploration. Differentiation of an adrenal hemorrhage from an adrenal cortical adenoma is well demonstrated through the report of prenatal sonographic findings of the fetus of a 31-year-old primagravida patient at 39 weeks gestation, consisting of a semisolid, semicystic heterogeneous mass appearing similar to those observed with neuroblastoma. Color and power Doppler imaging depicted an arterial feeding vessel originating in the fetal aorta, similar to that reported in association with neuroblastoma, thus enhancing sonographic differentiation of solid adrenal masses versus adrenal hemorrhage. 6 Adrenal hemorrhage may cause significant unconjugated hyperbilirubinemia. In the case of a 4-day-old neonate born by normal spontaneous vaginal delivery, jaundice began on the third day after birth, and excessive bilirubin levels remained unresponsive to phototherapy, suggestive of internal hemorrhage. Abdominal sonography revealed a right adrenal hematoma, which had fully resolved by follow-up examination at one month of age. 7 Rarely, settling of blood from the ruptured capsule of the hemorrhaged adrenal gland can produce the appearance of inguinoscrotal bruising, scrotal swelling, or scrotal hematoma; this presentation may occur unilaterally, bilaterally, or contralaterally. 8 Adrenal hemorrhage may mimic an acute scrotum and increase suspicion of testicular torsion, resulting in misdiagnosis and surgical intervention based solely on physical examination. Physical examination, clinical history, and sonographic evaluation of both testes and abdomen may reveal adrenal hemorrhage and allow conservative treatment, avoiding unnecessary surgical exploration of the scrotum. 9 There are no treatment procedures specific to neonatal adrenal hemorrhage. Serial sonographic studies are performed to monitor the progression of resolution of the hemorrhage. Adrenal hemorrhage will originally present as a heterogeneous mass and progress through a process of lysis over a period of weeks, producing varying levels of echoes suggesting resorption and liquefaction. A resolved adrenal hemorrhage will decrease in size and appear as residual calcification on serial abdominal sonograms over several weeks. Persistent review of serial studies will confirm diagnosis of hemorrhage and avoid unnecessary surgical procedures. Kidneys are expected to return to normal position. No palpable masses will be present. Once resolution has been confirmed, the child is expected to develop normally with no complications. Conclusion Neonatal adrenal hemorrhage may present through abnormal lab values, confirming findings such as hyponatremia, hyperbilirubinemia, or as an abdominal mass or bluish scrotal discoloration, as well as other presentations discussed earlier. Sonographically, it can be confirmed that the heterogeneous mass causes displacement and contour changes to the related kidney and verified that more serious conditions such as neuroblastoma, adrenal cortical adenoma, and acute scrotum do not exist. Sonography is the imaging modality of choice in evaluating abdominal masses in the neonate. Serial imaging is a sound method of tracking the course of this condition by determining avascularity of the mass to rule out a malignancy

5 EVALUATING NEONATAL ADRENAL HEMORRHAGE / Valdespino 225 and confirming the progression of resolution of the hemorrhage through calcification over a brief time, thereby avoiding unnecessary surgical exploration of the abdominal or testicular areas. Acknowledgments Deep gratitude and respect go to the author s mentor and anatomy professor, Ann Harmer, for her excellence in teaching, knowledgeable guidance, and constant encouragement. The author thanks Scott McCloud, Linda Hogsett, and Dave Duffy of University of California Irvine Medical Center; Kathryn Angel, Catherine Aguirre, and Joe DeMello of Kaiser Permanente Riverside Medical Center; and Harper Halprin for support in preparing the digital images for publication. References 1. Felc Z: Ultrasound in screening for neonatal adrenal hemorrhage. Am J Perinatol 1995;12: Schrauder MG, Hammersen G, Siemer J, et al: Fetal adrenal hemorrhage: two-dimensional and three-dimensional imaging. Fetal Diagn Ther 2008;23: Velaphi SC, Perlman J: Neonatal adrenal hemorrhage: clinical and abdominal sonographic findings. Clin Pediatr 2001;40: Deeg KH, Dachert C, Glockel U, Langer T: The different features of congenital neuroblastomas: report about the sonographic diagnosis of three cases. Ultraschall Med 2007;28: Hsieh C-C, Chao A-S, Hsu J-J, Chang Y-L, Lo L-M: Real-time and power Doppler imaging of fetal adrenal hemorrhage. Chang Gung Med J 2005;28: Sherer DM, Dalloul M, Wagreich A, et al: Prenatal sonographic findings of congenital adrenal cortical adenoma. J Ultrasound Med 2008;27: Gunlemez A, Karadag A, Degirmencioglu H, Uras N, Turkay S: Management of severe hyperbilirubinemia in the newborn: adrenal hematoma revisited. J Perinatol 2005;25: Noviello C, Cobellis G, Muzzi G, Pieroni G, Amici G, Martino A: Neonatal adrenal hemorrhage presenting as contralateral scrotal ematoma. Minerva Pediatr 2007;59: Adoriso O, Mattei R, Cardini E, Centonze N, Noccioli B: Neonatal adrenal hemorrhage mimicking an acute scrotum. J Perinatol 2007;27: