|Year : 2022 | Volume
| Issue : 1 | Page : 35-38
Congenital intracranial teratoma masquerading as encephalocele
Yahuza Mansur Adamu1, Mustapha Shuaibu Hikima2, Yusuf Lawal1
1 Department of Radiology, Bayero University/Aminu Kano Teaching Hospital, Kano, Nigeria
2 Department of Radiology, Muhammadu Abdullahi Wase Hospital, Kano, Nigeria
|Date of Submission||14-Oct-2021|
|Date of Decision||17-Dec-2021|
|Date of Acceptance||05-Jan-2022|
|Date of Web Publication||07-Jul-2022|
Yahuza Mansur Adamu
Department of Radiology, Bayero University/Aminu Kano Teaching Hospital, Kano
Source of Support: None, Conflict of Interest: None
Teratomas are rare tumors accounting for only 0.5% of all intracranial tumors. However, they are considered as the most common congenital brain tumors present at birth. Commonly, they are found in the sacrococcygeal region, head and neck, gonads, and the mediastinum, although they may be found in other parts of the body. An encephalocele on the other hand is an extracranial lesion with intracranial contents through a defect in the skull. The higher prevalence of encephaloceles often leads to misdiagnosis of other congenital diseases of the brain like tumors as encephalocele. We present a 29-day-old child who presented to the hospital on account of swelling on the skull which was noticed since birth and associated absence of hair over the swelling covered by intact skin with initial impression of encephalocele made. The role of imaging in these patients precisely computed tomographic scan and magnetic resonance imaging (MRI) cannot be overemphasized for appropriate diagnosis and surgical intervention. A radiological diagnosis of congenital intracranial teratoma was made and the patient had surgical excision of the tumor. Congenital intracranial teratoma are rare congenital malformations. The present report demonstrates the classic imaging features as seen on plain radiographs, computed tomography, and MRI which are indispensable for subsequent surgical intervention.
Keywords: Computed tomographic scan, congenital intracranial teratoma, encephalocele, infant, magnetic resonance imaging, plain radiograph
|How to cite this article:|
Adamu YM, Hikima MS, Lawal Y. Congenital intracranial teratoma masquerading as encephalocele. J Radiat Med Trop 2022;3:35-8
|How to cite this URL:|
Adamu YM, Hikima MS, Lawal Y. Congenital intracranial teratoma masquerading as encephalocele. J Radiat Med Trop [serial online] 2022 [cited 2022 Aug 7];3:35-8. Available from: http://www.jrmt.org/text.asp?2022/3/1/35/350087
| Introduction|| |
Congenital brain tumors are very rare and account for only 0.5%–1.5% of all childhood brain tumors. Germ cell tumors constitute 0.4%–3.1% of all intracranial tumors and teratomas constitute 9%–30% of them.
Teratomas are rare tumors accounting for only 0.5% of all intracranial tumors. However, they are considered as the most common congenital brain tumors present at birth. Commonly, they are found in the sacrococcygeal region, head and neck, gonads, and the mediastinum, although they may be found in other parts of the body. They contain more than one germ layer, usually two, but may contain all the three germ layers (ectoderm, mesoderm, and endoderm).
An encephalocele on the other hand is an extracranial location of intracranial contents through a defect in the skull. The higher prevalence of encephaloceles often leads to misdiagnosis of other congenital diseases of the brain like tumors as encephalocele.
The case of an infant who presented with an intracranial teratoma initially thought to be an encephalocele is presented below.
| Case Report|| |
AK is a 29-day-old child who was presented at the pediatric outpatient department of Aminu Kano Teaching Hospital with complaint of swelling on the skull which was noticed since birth and associated absence of hair over the swelling [Figure 1]. The child was delivered through vaginal delivery in a general hospital at term where pregnancy was booked. The mother has 3 other children. There is no history of similar mass in other children. She attended regular antenatal visits. Although obstetric ultrasound scan was done on two occasions during her pregnancy, the mass was not noticed until after her delivery.
On physical examination, general condition of the child was good. She was alert with interest in the environment. There was a soft tissue mass overlying the vertex which is covered by intact skin but devoid of overlying hair. It measured about 9 cm × l0 cm in size [Figure 1]. An initial clinical impression of encephalocele was made.
Plain radiograph of the skull showed about 4 cm bony defect at the vertex with an overlying fairly rounded, soft tissue mass with regular outline [Figure 2]. Multiple oval-shaped calcific opacities were also noted within the mass. The remaining parts of the calvarium appeared normal.
|Figure 2: Plain abdominal radiograph showing a defect at the vertex with overlying soft tissue swelling (arrows). Multiple opacities of calcific density are also seen within the mass|
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Computed tomography (CT) of the brain showed an extensive, midline, hypodense mass with negative attenuation (HU = −50–−95) seen in the supra sellar region, extending superiorly to the vertex and via a 4 cm defect at the vertex, extending into the scalp tissues [Figure 3]. There were multiple, oval-shaped hyperdense masses (HU = 98–110) seen within the mass due to calcification/tooth elements [Figure 3]. There is associated widening of the space between the bodies of the lateral ventricles by this mass [Figure 3].
|Figure 3: Sagittal, noncontrast reformatted computed tomogram of the brain showing a hypodense mass (arrows) extending from the scalp to the region of the lateral ventricles (HU = −65)|
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On magnetic resonance imaging (MRI) (done when child was 4-month-old), the mass appeared hyperintense on both T1 and T2-weighted images signifying fatty content [Figure 4], [Figure 5]. The hyperdense masses within it on CT appeared as signal void [Figure 4] and [Figure 5].
|Figure 4: Axial FLAIR magnetic resonance image showing an oval-shaped, hyperintense mass in the midline, between the bodies of the lateral ventricles. There is an intralesional hypointense mass due to calcification|
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|Figure 5: Coronal Tl-weighed magnetic resonance image showing a hyperintense mass within the midline, between the bodies of the lateral ventricles. A superficial component of the mass is seen at the vertex|
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A radiological diagnosis of congenital intracranial teratoma was made and the patient had surgical excision of the tumor. Histology done on specimen acquired at surgery confirmed the diagnosis of intracranial teratoma. The patient was stable 6 months after surgery on follow-up.
| Discussion|| |
Teratomas may occur anywhere in the body; however, the most common location is the sacral region. When intracranial in location, they occur in the pineal or suprasellar regions. They are the most common germ cell tumors to be present at birth, accounting for 0.5% of all intracranial tumors. Teratomas of the head and neck are very rare, comprising l%–3.5% of all cases.,,,
Histopathologically, teratomas are typically divided into three groups: (i) mature, (ii) immature, and (iii) malignant. Mature teratomas contain well-differentiated cells, while immature teratomas contain primitive structures that are not adequately differentiated. Teratomas that contain malignant component are classified as malignant teratomas.
According to O'Connor and Norris, mature teratoma is grade 0, immature teratoma is classified into 3, based on the proportion of its immature elements and the mitotic rate. In this patient, the histological diagnosis was mature teratoma, benign form (Grade 0). The symptoms of intracranial teratomas may include visual disturbance, polydipsia, and polyuria.
The diagnosis of congenital intracranial teratoma may be made prenatally and this is useful in guiding obstetric decision-making. Routine prenatal ultrasound may detect fetal intracranial tumors early, and MRI is crucial in determining tumor characteristics and extent. In our patient, although obstetric ultrasound was done during antenatal care, the mass was not identified.
Intracranial teratomas are usually located in the pineal, parasellar, or suprasellar regions and usually appear as ovoid or lobulated mass with or without multilocularity. They appear as heterogenous density on CT due to different components such as soft tissue, cartilage, bone, and fat. This is the case in this patient, where the tumor appeared as a mixed density mass, with fat and calcific densities.
On MRI, they appear as mixed intensity masses due to their heterogeneity. In this patient, the tumor appeared as a mixed intensity mass (predominantly hyperintense due to the presence of fat) with signal void areas due to the presence of intratumoral calcifications.
Both mature and immature teratomas have similar radiological feature, however, when cysts are present, mature ones tend to have larger calcifications. In this patient, there were no cysts within the tumor, however, numerous calcifications were found within the tumor. When solid component is present, it may show enhancement which may be marked in case of malignant intracranial teratoma.,
The differential diagnosis of intracranial teratomas includes other germ cell tumors such as germinoma, yolk sac tumor, choriocarcinoma and embryonal carcinoma, and craniopharyngioma.,
The treatment of intracranial teratoma is surgical resection. The prognosis of surgery with mature teratomas is good; with patients having 93% survival rate at 10 years, however, a phenomenon of tumor recurrence has been reported and is referred to as growing teratoma syndrome.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]