Case Reports

Primary Orbital Malignant Teratoma - A Case Report

Grace F D’costa*, Meenal S Hastak*, Yoganand V Patil**

Abstract
Orbital teratomas are uncommon and account for only 1% of orbital tumours in childhood, though their existence was noted a century ago. Malignant teratomas are extremely rare and limited to case reports. We report such a rare case in a one year old male child who presented with gradually increasing proptosis of the left eye, since six months of age. CT Scan and USG revealed a soft tissue mass in the inferomedial aspect of the left orbit, with intracranial extension but without intraocular extension. AFP levels were high. A left eye orbitotomy with excision of the tumour mass in toto was done.

Introduction

Orbital teratomas are rare tumours and
their histogenesis is the survival and proliferation of ectopic pleuripotent germ cells deposited during embryogenesis. They are more commonly seen in females M:F=5:14, the left eye is more commonly involved compared to the right eye and they usually exhibit abundance of tissues from the ectoderm and mesoderm but endodermal tissues are scanty. Histological evidence of malignancy is extremely rare. Our case was a one year old male child who presented with gradually increasing proptosis and high AFP levels. The tumour was excised in toto and revealed mature tissues from all the three germ cell layers with a component of endodermal sinus tumour, qualifying for a diagnosis of malignant teratoma.

Case Report

A one year old male presented with gradually increasing proptosis since 6 months of age, with watering and sanguinous discharge of the left eye. On examination there was conjunctival chemosis, discharge was present, the pupils were reacting to light, the lens was normal. The extraocular muscles showed restricted movement medially. The fundus, showed disc hyperaemia and blurred margins. The macula was oedematous with tortuosity of veins. A CT Scan showed a heterogeneously enhancing soft tissue mass in the left orbit, causing pressure erosion, with intracranial but no intraocular extension. A USG showed evidence of a large hypoechoic mass in the inferomedial aspect of the left eye, the posterior segment was normal and the optic nerve was pushed laterally. A left eye, orbitotomy with complete excision of the tumour was done, there was extrusion of cheesy material at surgery. The eye ball was repositioned in the orbital cavity.

Pathological Findings

FNAC : Malignant small round cell tumour.
Gross : Multiple bits of tumour tissue with muscle totally measuring 2.5 x 2.5 x 2.5 cms.

Histopathology

It showed mature tissue from all three germ cell layers, endoderm, mesoderm and ectoderm i.e. respiratory and small intestinal epithelium, fibrous and skeletal muscle tissue and skin with horn cysts. In addition there was a component of endodermal sinus tumour.

Fig. 1 : Photograph showing left eye orbitotomy.	Fig. 2 : Photomicrograph showing intenstional tissue of endodermal origin (H&E, x 100)	Fig. 3 : Photomicrograph showing keratinous cyst of ectodermal origin (H&E, x 100)
Fig. 4 : Photomicrograph showing respiratory epithelium of endodermal origin and fibrous and muscle tissue of mesodermal origin (H & E, x100)	Fig. 5 : Photomicrograph showing endodermal sinus compartment (H&E, x 100)

Discussion

Orbital teratomas are uncommon tumours and account for only 1% of orbital tumours in childhood.1 Their histogenesis is the survival and proliferation of ectopic pleuripotent germs cells deposited during embryogenesis.2 They are more commonly seen in females1 M:F=5:14, our case however was a male. The left eye is more commonly involved,3 as was our case.

Most of the presentations are at birth,1,4 a 27 week foetus has also been described,5 our case presented at six months of age but was diagnosed at the age of one year. Mahesh et al3 also described a case presenting at the age of ten months.

Many of the cases had intracranial extension,4-6 in our case also there was intracranial extension but not intraocular extension, as reported by Kivela et al.6

Histology reveals the presence of tissues from all the three germ cell layers, with abundance of tissues from the ectoderm and mesoderm. In our case however the tumour showed tissue from all the three germ cell lines in equal proportion. Malignant transformation in an orbital teratoma is rare. There are few reports in the literature3,5,6,8,9 the malignant component often constitutes, endodermal sinus tumour5,8 as was seen in our case.

References

1. Spinelli HM, Criscuolo GR, Tripps M, Buckley PJ.Massive orbital teratoma in the newborn. Ann Plast Surg 1993; 31 (5) : 453-8.
2. Smirniotopoulos JG, Chiechi MV Teratomas, dermoids, and epidermoids of the head and neck. Radiographics 1995; 15 (6) : 1437-55.
3. Prause JU, Borgesen SE, Carstensen H, et al. Cranio-orbital teratoma. Acta Ophthalmol Scand Suppl.1996; 219 : 53-6.
4. Lee JC, Jung SM, Chao AS, Hsueh C. Congenital mixed malignant germ cell tumor involving cerebrum and orbit. J Perinat Med 2003; 31 (3) : 261-5.
5. Garden JW, McManis JC. Congenital orbital-intracranial teratoma with subsequent malignancy: case report. Br J Ophthalmol 1986;70 (2) : 111-3.
6. Kivela T, Tarkkanen A. Orbital germ cell tumors revisited: a clinicopathological approach to classification. Surv Ophthalmol 1994; 38 (6) : 541-54.
7. Kusumakumari P, Geetha N, Chellam VG, Nair MK. Endodermal sinus tumors in the head and neck region. Med Pediatr Oncol 1997; 29 (4) : 303-7.
8. Saradarian : Malignant teratoma of the orbit. Arch Ophthalmol 1947; 37 : 253.