Prenatal diagnosis of a cavernous angioma associated with intracranial hemorrhage: report of one case and review of the literature

Abstract

A 27-year-old, nulliparous woman was referred for evaluation of a mass in the posterior fossa of the fetal brain at 20 weeks' gestation. Sonographic examination revealed a large complex mass interposed between the occipital lobes of the brain and the cerebellum. The mass consisted predominately of fluid and had an echogenic area of 1.5 cm in length just above the cerebellum (Figures 1 and 2). The falx cerebri and tentorium cerebelli were widely separated. Color Doppler examination showed the presence of low-flow signals near the stalk of the mass. No interruption of blood flow in the dural sinuses could be identified, ruling out the possibility of thrombosis of the dural sinuses1, 2. Ultrafast magnetic resonance imaging (MRI) confirmed the brain lesion (Figure 3). GRASS T2 + W and T1W showed signs suggestive of calcification and subacute hemorrhage in the lesion, respectively. No flow signals were detected. Three-dimensional ultrasound examination did not reveal any additional information. Abdominal ultrasound images of intracranial hemorrhage associated with cavernous angioma. (a) Sagittal view showing a complex echogenic mass (*) above the cerebellum. (b) Color Doppler image showing the presence of low-flow signals at one end of the mass (*). Vaginal ultrasound image of intracranial hemorrhage associated with cavernous angioma: transverse view of the fetal brain showing a wide separation of the two leaflets of the falx cerebri (∧) with a hypoechogenic shadow (M) in the posterior fossa. T2-weighted ultrafast magnetic resonance image of fetal intracranial hemorrhage associated with cavernous angioma showing a hypointense mass (*) in the posterior fossa. Maternal blood investigations, including prothrombin time, partial thromboplastin time, platelet count, TORCH (toxoplasmosis, syphilis, rubella, cytomegalovirus, and herpes simplex virus) titre, antithrombin III, factor V Leiden, von Willebrand factor, anticoagulant protein S, activated protein C, anticardiolipin, antiphospholipid and antinuclear antibodies, showed normal results. One week later, two-dimensional ultrasound revealed that the fluid part of the complex mass had increased. Given the lack of information about this rare condition, the poor prognosis associated with intracranial hemorrhage3, and that the upper limit for a legal pregnancy termination in Hong Kong is 24 weeks, the couple opted for termination of pregnancy. Fetal blood collected before termination showed a hemoglobin level of 9.7 g/dL, a platelet count of 129 × 109/L and a normal female karyotype (46,XX). Autopsy confirmed the presence of severe hemorrhage within the falx cerebri and tentorium cerebelli, and a 2-cm3 dark red hard mass between the two leaflets of the tentorium cerebelli (Figure 4). Histological examination of the mass revealed a cavernous angioma containing a calcified thrombus. The angioma was formed by dilated sinusoidal spaces lined with thin endothelium with no elastic or muscular layer. Autopsy photographs of intracranial hemorrhage associated with a cavernous angioma. (a) Demonstration of extradura hemorrhage separating the two leaflets of the dura in the posterior fossa after opening up the skull bone. (b) Demonstration of a dark mass (*) attached firmly to the tentorial cerebelli after removal of blood in the posterior fossa. This mass corresponds to the complex echogenic mass seen on ultrasound examination. Cerebral cavernous angiomas are extremely rare in the fetal and neonatal period. The clinical data of nine reported cases4-11 along with the present case are summarized in Table 1. The risk of hemorrhage (50%) is higher in the fetal group than it is in all other age groups (10–45%)11. Three out of the four cases which presented with hemorrhage ended in either death or moderate mental retardation. Poor prognosis was also observed in neonatal cavernous angiomas which presented with severe intracranial hemorrhage12. Although postnatal MRI is very accurate in the identification of cerebral cavernous angioma10, 13, 14, both our case and a previous one10 suggest that antenatally the differential diagnosis from a simple hematoma may be difficult. The characteristic features of an adult cavernous angioma, namely a central reticulated core of mixed signal intensity surrounded by a prominent hypointense rim, were absent, probably because of the lack of hemosiderin in fetal life10. Cavernous angioma should be included in the differential diagnosis of severe fetal intracranial hemorrhage even if imaging findings suggest a simple hematoma. K. Y. Leung*, M. H. Y. Tang**, T. P. W. Lam , Y. W. Fan?, T. W. H. Shek , K. Y. Wong?, C. S. W. Ngai*, * Departments of Obstetrics and Gynecology, The University of Hong Kong, Queen Mary Hospital, Hong Kong, SAR, Department of Radiology, The University of Hong Kong, Queen Mary Hospital, Hong Kong, SAR, Department of Pathology, The University of Hong Kong, Queen Mary Hospital, Hong Kong, SAR, ? Department of Paediatrics Adolescence Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, SAR, ? Division of Neurosurgery, Department of Surgery, The University of Hong Kong, Queen Mary Hospital, Hong Kong, SAR, ** Prenatal Diagnostic Counselling Department, Tsan Yuk Hospital, Hong Kong, SAR