Clinical Presentation
A 3150 g infant girl was born at 38 weeks gestation to an 18-year-old gravida 2 para 0 mother. An intrauterine sonogram and subsequent fetal magnetic resonance imaging (MRI) (Figure 1) demonstrated a large orbital mass. At birth a 5 cm exophytic right orbital mass was present. The infant had a postnatal orbital computed tomography (CT) and MRI (Figure 2). In preparation for resection, an angiogram was performed that demonstrated the mass had arterial supply from the middle meningeal artery and right ophthalmic artery (Figure 3). The branches to the right middle meningeal artery were embolized with a butylcyanoacylate/ethiodol solution. The next day the tumor was resected.
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Figure 1.
(a) Coronal T2-weighted and (b) axial T2 half Fourier acquisition single-shot Turbo spin-echo (HASTE) (rapid acquisition) images from fetomaternal MRI. A large heterogeneous right orbital mass (arrows) is present containing probably large cystic spaces which have the same signal as amniotic fluid.
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Figure 2.
(a) Axial T2-weighted and (b) axial T1-weighted images, (c) axial computed tomography (CT) image soft tissue window. The orbital mass (arrows) on the postnatal images is again seen to have a markedly heterogeneous signal with areas of fluid. The CT image confirms the presence of extensive calcification and ossification (white arrowhead) but without well-formed osseous structures.
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Figure 3.
Lateral subtraction angiogram demonstrating blood flow to the tumor from the ophthalmic artery (white arrow) and middle meningeal artery (black arrow).
Denouement and Discussion
The patient underwent orbital exploration with resection of the globe and a large inseparable tumor and also contouring of the lateral margin of the boney orbit and placement of an orbital prosthesis. Pathologic examination of the resected tumor and attached orbit demonstrated a large mature teratoma and a maldeveloped eye with retinal dysplasia.
Orbital teratomas are rare, usually benign, congenital tumors. They have been divided into four different groups: (1) complete orbital fetus-in-fetu -- orbitopagus parasiticus, (2) incomplete second fetus including spine, (3) true orbital teratoma with all three germ layers, (4) dermoid tumor with only two germ cell lines. The presence of a spinal column and the presence of organized tissues confirm the diagnosis of fetus-in-fetu. Well-documented cases of orbital fetus-in-fetu (types 1 and 2) are very rare. Most cases of fetus-in-fetu are intra-abdominal, usually retroperitoneal. Other reported locations include cerebral ventricle, liver, scrotum and oropharynx. Most reported cases have been of type 4, dermoid cysts. True orbital teratomas, as in this case, are rare.
Orbital teratomas characteristically are massive and cause severe facial deformity and disfigurement including proptosis and eyelid stretching. They may enlarge the orbital to 2 or 3 times normal. Most orbital teratomas are benign and well differentiated histologically. Immature and malignant orbital teratomas are rare. At imaging, benign orbital teratomas are usually multiloculated, cystic masses with an admixture of tissues including calcification, fat and ossification. They are sharply circumscribed. The differential diagnosis of a cystic orbital mass in a neonate includes dermoid cyst, epidermoid inclusion cysts, hemangioma or lymphangioma and cephalocele. Dermoid cysts are unilocular and have a single fat-fluid level. Epidermoid inclusion cysts, probably because of their proteinaceous contents are usually similar in appearance to water or cerebral spinal fluid on CT. Lymphangiomas are multilocular, but do not contain fat or calcification. Cephaloceles contain cerebral spinal fluid, and generally have adjacent osseous abnormalities, but unlike teratomas and dermoids, cephaloceles do not contain lipid.
The treatment of orbital teratoma is surgical resection and usually exenteration. The goal of surgery is to allow normal orbitofacial development and maintain adequate cosmetic outcome. This was performed in this case with contouring of the boney orbit and placement of an orbital prosthesis.