Cli~.Radiol. (1979) 30, 435-440
The Computerised Tomographic Findings in paediatric Orbital Tumours ttlLTON I. PRICE and ALLAN DANZIGER
From the Department of Diagnostic Radiology, Johannesburg General Hospital, and University of Witwatersrand Medical School Forty-two patients with histologically proven orbital tumours are presented. CT is of value in the pretreatment assessment and in delineating the extent of the orbital tumour. The surrounding bony destruction and intracranial extension are easily assessed. Post-treatment follow-up can be closely monitored using CT.
Computerised tomography (CT) has made a great impact on the diagnosis and management of orbital disease. Small lesions may be readily detected due to the natural radiographic contrast provided by the orbital fat and to the high resolution of the CT scanner. Orbital tumours in the paediatric age group are not uncommon, and the value of CT cannot be overemphasised as it is non-invasive, accurate and rapidly performed. MATERIALS AND METHODS Forty-two paediatric patients with orbital turnouts were scanned using an EMI Mark I head scanner with a 160 x 160 matrix. The scans were performed using an 8 mm Collimator with the patient's head positioned so that the scanning plane was parallel to the course of the optic nerves (Ambrose et al., 1974). Intravenous iodinated contrast medium was used on a l cc/kg basis as a routine. The histological diagnoses are presented in Table 1.
Retinoblastoma This is the most common intraocular malignant condition of childhood (Nicholson and Green, 1975) which, if diagnosed early, can be successfully treated. The incidence is quoted at between one case in Table 1
Diagnosis
Number of. patients
Retinoblastoma Rhabdomyosarcoma Optic nerve glioma Optic chiasmal glioma Leukaemia Secondary neuroblastoma
33 5 1 1 1 1
Total
42
17 0 0 0 - 3 4 0 0 0 live births (Nicholson and ~Green, 1975); however, in South Africa, the incidence is higher (Friedman and Goldberg 1976). The diagnosis is most frequently made between the ages of 1½ 2 years. Most cases occur sporadically; however, in approximately 6% o f cases there is a familial tendency (Nicholson and Green, 1975). Multiple sites of origin in the same or fellow eye, are common. Dissemination may occur within the globe, along the optic nerve into the subarachnoid space or intracranial cavity, or via the vascular choroid to distant sites. The clinical findings include leukokoria, strabismus, a painful red eye with glaucoma, and poor vision. The prognosis depends on the extent of the disease at the time of diagnosis. The earlier manifestation on CT is a high density intraocular lesion which does not enhance significantly following intravenous iodinated contrast medium (Fig. 1). Areas of calcification are often present within the mass. The globe is usually not grossly enlarged until late in the disease. Spread of tumour beyond the confines of the globe may be manifest by thickening of the optic nerve of continuity with the intraocular mass (Fig. 2). There may be a large retro-orbital mass obscuring or involving the optic nerve (Fig. 3). CT easily demonstrates intracranial extension of the tumour (Fig. 4a, b). In the absence of calcification, the CT findings are not usually specific, and a biopsy is still required to establish the final diagnosis. CT is very useful in detecting the presence of a tumour, and in assessing its degree of local spread. It is very useful in following the patient after treatment and will identify a recurrence in the same or opposite orbit, at an early stage.
Rhabdomyosarcoma This is the most common primary orbital malignant condition o f childhood (Frayer and Enterline, 1959;
436
CLINICAL RADIOLOGY
k ~k~'
A
!
J
lJ
y"
Fig. 1 (top left) - Retinoblastoma which is confined to the right globe. Note the calcification within the t u m o u r bulk, The globe is b o t h enlarged and proptotic. There is a second smaller retinoblastoma in t h e medial aspect of the left globe,
Fig. 2 (top right) A large retinoblastoma which has involved the right optic nerve and caused a proptosis.
Fig. 3 (bottom left) - A large retinoblastoma that has extended to involve the retro-orbital space. Only the most proximal part of the optic nerve can be identified.
Fig. 4 - Intracranial extension of a retinoblastoma seen before (a, left) and after (b, right) intravenous iodinated contrast m e d i u m .
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unilateral proptosis. There is usually a ptosis and a palpable orbital or lid mass. The prognosis depends on the cell type, extent of the disease at the time o f diagnosis and the type of therapy. Metastases to the brain and lungs are common. The CT findings are a mass extending inside and outside the muscle cone of the orbit. The orbital wall is usually infiltrated (Hilal and Trokel, 1977) (Fig. 5). The lesion is usually distinct from the globe and causes a significant degree of proptosis. In one patient, there was a marked degree of enhancement after administration o f iodinated contrast medium (Fig. 6a, b). CT offers an accurate and rapid means of following the progress after treatment (Fig. 7).
Leukaemia and Lymphoma Fig. 5 -- A seven-year-old child with a rhabodomyosarcoma. Note a large retro-orbital mass influencing the adjacent bony structures. The optic nerve is visualised. Porterfield and Zimmerman, 1962). It occurs predominantly in Caucasians in the frst decade of life (average age seven years). It is rare over the age of 20 years, and over 90% of cases occur below 16 years of age (Nicholson and Green, 1975). There are three histologic types: embryonal rhabdomyosarcoma (commonest), alveolar rhabdornyosarcoma (second most common), and the differentiated rhabdomyosarcoma (least common). Clinically they present with a rapidly progressive
Orbital involvement in leukaemia may be due to soft tissue infiltration by leukaemic cells, orbital extramedullary haematopoiesis or orbital haernorrhage. Leukaemia accounts for only 1.9% of orbital tumours in children (Nicholson and Green, 1975). The orbital bones and soft tissues are usually infiltrated with malignant cells. The histological differentiation between lymphoma and leukaemia may be difficult. However, the clinical, haematological and radiological findings will usually help establish the final diagnosis (Porterfield and Zimmerman, 1962). Lymphomas other than Burkitt's rarely cause orbital infiltration early in the disease. It tends to arise in front of the orbital septum and outside the
Fig. 6 - A two-year-old child with a rapidly increasing left sided proptosis (a, left). Marked enhancement of the retroorbital rhabdomyosarcorna is seen to be distinct from the globe (b, right).
438
CLINICAL RADIOLOGY
Fig. 7 - Same patient as in Fig. 5, following radiotherapy. There is a marked reduction in the turnout size.
Fig. 8 - Three-year-old child with acute leukaemia showing infiltration of the left optic nerve.
muscle cone because there is no lymphoid tissue behind the anterior orbital septum (Hilal and Trokel, 1977). The CT findings in our patient with leukaemia was a thickened optic nerve which showed no change with contrast medium. There was a slight proptosis (Fig. 8).
larity of the optic nerve. Occasionally an area of calcific density involving a small segment of the optic nerve may be detected (Hilal and Trokel, 1977). Usually the optic nerve cannot be separated from the tumour. The enhancement of the tumour following intravenous iodinated contrast medium is variable and usually only moderate (Hilal and Trokel, 1977). It is important in all patients with optic nerve glioma to search for intracranial extension of the neoplasm. The chiasm must be examined with intravenous contrast in all patients. The tumour mass itself may be visible as well as distortion of the basal cisterns and the lower portion of the third ventricle. In Fig. 9a, a large bulbous optic nerve glioma with intracranial extension involving the optic chiasm is noted. Moderate enhancement of the lesion was observed following the administration of intravenous iodinated contrast medium (Fig. 9b). Fig. 10a, b shows an optic chiasmal glioma in a five-year-old boy. On the precontrast scan (Fig. 10a), there is a large area of low density with peripheral calcification. This lesion caused marked hydrocephalus of the lateral and third ventricles, and after intravenous contrast medium (Fig. 10b) there was marked homogeneous enhancement of the tumour.
Gliomas of the Optic Nerve and Optic Chiasm Optic nerve gliomas constitute 3% of childhood orbital turnouts (Nicholson and Green, 1975)and are most frequently diagnosed between 4 and 10 years of age. The majority are benign astrocytomas and are slow growing and do not metastasise. The morbidity and mortality are due to local enlargement and compression of adjacent neural structures. Evidence of Von Recklinghausen's disease is present in approximately 11% of cases (Porterfield and Zimmerman, 1962). There is typically bulbous enlargement of the orbital portion of the optic nerve and the meninges are markedly thickened. The tumour may extend peripherally towards the eye or centrally towards the brain. The tumour mass is encapsulated within the muscle cone and the globe is displaced axially. Clinically, intraorbital optic nerve gliomas present with proptosis and loss of vision. The intracranial gliomas of the orbital pathway present with loss of vision and signs of raised intracranial pressure. The CT findings include thickening and irregu-
Metastatic Orbital Tumours Orbital metastases in children have been described most frequently in association with neuroblastoma and less frequently with Ewing's sarcoma (Albert et al., 1967)_
THE
COMPUTERISED
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FINDINGS
IN PAEDIATRIC
ORBITAL
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439
Fig. 9 (a, left, b, right) Four-year-old child with a left optic nerve glioma showing extensive intracranial extension. Note the marked enhancement in b.
Fig. 10 - Marked homogeneous enhancement in an optic chiasmatic glioma in a three-year-old child (b, right). In the precontrast scan (a, left) there is an area of low density with peripheral calcification in the optic chiasm region. Note the obstructive hydrocephalus.
Orbital metastases generally occur late in the course of neuroblastoma. Initial orbital involvement occurs in less than 5% of cases (Nicholson and Green, 1975). Orbital metastases may however precede detection o f the primary site of tumour origin by as long as nine months (Nicholson and Green, 1975). The metastases may be unilateral or bilateral. Neuroblastomas which most frequently metastasise to the
orbit, arise in the abdomen or pelvis and less frequently in the chest (Albert et aL, 1967). Clinical features of metastatic neuroblastoma to the orbit include spontaneous lid ecchymosis, palpable swelling (often fluctuant) of the adjacent zygomatic bone due to bony metastasis, radiographic evidence o f bone destruction. The CT findings in our patient were of a small high
440 density mass situated behind the significant change after contrast.
CLINICAL RADIOLOGY globe with no
CONCLUSION CT does n o t allow for an absolute histological diagnosis in paediatric orbital turnouts; however, it is of considerable value in the p r e t r e a t m e n t assessm e n t o f the e x t e n t of the tumour. The retro-erbital and intracranial e x t e n s i o n of the t u m o u r are readily assessed, as well as i n v o l v e m e n t o f the b o n y orbit. CT offers a rapid, accurate and non-invasive assessm e n t of the orbit postsurgery and or radiotherapy.
REFERENCES
Mbert, D. M., Rubenstein, R. A. & Scheie, H. G. (1967). Tumour metastases to the eye. Part II. Clinical study in infants and Children. American Journal c~f Ophthalmology, 63, 727. Ambrose, J. A. E., Lloyd, G, A. S. &Wright, J. E. (1974). A
preliminary evaluation of fine matrix computerised axial tomography (EMI scan) in the diagnosis of orbital space occupying lesions. British Journal o f Radiology, 47 (563) 747 -751. Frayer, W. C. & Enterline, H. T. (1959). EmbrYonal rhabdomyosarcomas of the orbit m children and Young adults. Archives of Ophthalmology, 62, 203-210. Friedman, J. & Goldberg, L. (1976). Incidence of retino. blastoma in Bantu of South Africa. British JoUrnal of Ophthalmology, 60, 655. Hilal Sadek, K. & Trokel, Stephen L. (1977). Computerised tomography of the orbit using thin sections. Seminars in Roentgenology, 12 (2), 137 -147. Nicholson, Don H. & Green, Richard W. (1975). Paediatric Ophthalmology, (ed. Robinson, D. Harley), Chap. 33, pp. 923, 930-933, 1023, 1032, 1033, 1039, W. 13. Saunders Co. Porterfield, J. F. & Zimmerman, L. E. (1962). Orbital rhabdomyosarcomas. A clinicopathologic study of 55 cases. Virchows Archiv fiir pathologische Anatomic, 335, 329_ Porterfield, John, F. (1962). Orbital turnouts in children: a report of 214 cases. International Ophthalmology Clin&s: Turnouts of the eye and Adnexa (ed. Zimmerman, Lorenz E.), Vol. 2, No. 2, pp. 319-335.
The Computerised Tomographic Findings in paediatric Orbital Tumours ttlLTON I. PRICE and ALLAN DANZIGER
From the Department of Diagnostic Radiology, Johannesburg General Hospital, and University of Witwatersrand Medical School Forty-two patients with histologically proven orbital tumours are presented. CT is of value in the pretreatment assessment and in delineating the extent of the orbital tumour. The surrounding bony destruction and intracranial extension are easily assessed. Post-treatment follow-up can be closely monitored using CT.
Computerised tomography (CT) has made a great impact on the diagnosis and management of orbital disease. Small lesions may be readily detected due to the natural radiographic contrast provided by the orbital fat and to the high resolution of the CT scanner. Orbital tumours in the paediatric age group are not uncommon, and the value of CT cannot be overemphasised as it is non-invasive, accurate and rapidly performed. MATERIALS AND METHODS Forty-two paediatric patients with orbital turnouts were scanned using an EMI Mark I head scanner with a 160 x 160 matrix. The scans were performed using an 8 mm Collimator with the patient's head positioned so that the scanning plane was parallel to the course of the optic nerves (Ambrose et al., 1974). Intravenous iodinated contrast medium was used on a l cc/kg basis as a routine. The histological diagnoses are presented in Table 1.
Retinoblastoma This is the most common intraocular malignant condition of childhood (Nicholson and Green, 1975) which, if diagnosed early, can be successfully treated. The incidence is quoted at between one case in Table 1
Diagnosis
Number of. patients
Retinoblastoma Rhabdomyosarcoma Optic nerve glioma Optic chiasmal glioma Leukaemia Secondary neuroblastoma
33 5 1 1 1 1
Total
42
17 0 0 0 - 3 4 0 0 0 live births (Nicholson and ~Green, 1975); however, in South Africa, the incidence is higher (Friedman and Goldberg 1976). The diagnosis is most frequently made between the ages of 1½ 2 years. Most cases occur sporadically; however, in approximately 6% o f cases there is a familial tendency (Nicholson and Green, 1975). Multiple sites of origin in the same or fellow eye, are common. Dissemination may occur within the globe, along the optic nerve into the subarachnoid space or intracranial cavity, or via the vascular choroid to distant sites. The clinical findings include leukokoria, strabismus, a painful red eye with glaucoma, and poor vision. The prognosis depends on the extent of the disease at the time of diagnosis. The earlier manifestation on CT is a high density intraocular lesion which does not enhance significantly following intravenous iodinated contrast medium (Fig. 1). Areas of calcification are often present within the mass. The globe is usually not grossly enlarged until late in the disease. Spread of tumour beyond the confines of the globe may be manifest by thickening of the optic nerve of continuity with the intraocular mass (Fig. 2). There may be a large retro-orbital mass obscuring or involving the optic nerve (Fig. 3). CT easily demonstrates intracranial extension of the tumour (Fig. 4a, b). In the absence of calcification, the CT findings are not usually specific, and a biopsy is still required to establish the final diagnosis. CT is very useful in detecting the presence of a tumour, and in assessing its degree of local spread. It is very useful in following the patient after treatment and will identify a recurrence in the same or opposite orbit, at an early stage.
Rhabdomyosarcoma This is the most common primary orbital malignant condition o f childhood (Frayer and Enterline, 1959;
436
CLINICAL RADIOLOGY
k ~k~'
A
!
J
lJ
y"
Fig. 1 (top left) - Retinoblastoma which is confined to the right globe. Note the calcification within the t u m o u r bulk, The globe is b o t h enlarged and proptotic. There is a second smaller retinoblastoma in t h e medial aspect of the left globe,
Fig. 2 (top right) A large retinoblastoma which has involved the right optic nerve and caused a proptosis.
Fig. 3 (bottom left) - A large retinoblastoma that has extended to involve the retro-orbital space. Only the most proximal part of the optic nerve can be identified.
Fig. 4 - Intracranial extension of a retinoblastoma seen before (a, left) and after (b, right) intravenous iodinated contrast m e d i u m .
THE COMPUTERISED
TOMOGRAPHIC
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437
unilateral proptosis. There is usually a ptosis and a palpable orbital or lid mass. The prognosis depends on the cell type, extent of the disease at the time o f diagnosis and the type of therapy. Metastases to the brain and lungs are common. The CT findings are a mass extending inside and outside the muscle cone of the orbit. The orbital wall is usually infiltrated (Hilal and Trokel, 1977) (Fig. 5). The lesion is usually distinct from the globe and causes a significant degree of proptosis. In one patient, there was a marked degree of enhancement after administration o f iodinated contrast medium (Fig. 6a, b). CT offers an accurate and rapid means of following the progress after treatment (Fig. 7).
Leukaemia and Lymphoma Fig. 5 -- A seven-year-old child with a rhabodomyosarcoma. Note a large retro-orbital mass influencing the adjacent bony structures. The optic nerve is visualised. Porterfield and Zimmerman, 1962). It occurs predominantly in Caucasians in the frst decade of life (average age seven years). It is rare over the age of 20 years, and over 90% of cases occur below 16 years of age (Nicholson and Green, 1975). There are three histologic types: embryonal rhabdomyosarcoma (commonest), alveolar rhabdornyosarcoma (second most common), and the differentiated rhabdomyosarcoma (least common). Clinically they present with a rapidly progressive
Orbital involvement in leukaemia may be due to soft tissue infiltration by leukaemic cells, orbital extramedullary haematopoiesis or orbital haernorrhage. Leukaemia accounts for only 1.9% of orbital tumours in children (Nicholson and Green, 1975). The orbital bones and soft tissues are usually infiltrated with malignant cells. The histological differentiation between lymphoma and leukaemia may be difficult. However, the clinical, haematological and radiological findings will usually help establish the final diagnosis (Porterfield and Zimmerman, 1962). Lymphomas other than Burkitt's rarely cause orbital infiltration early in the disease. It tends to arise in front of the orbital septum and outside the
Fig. 6 - A two-year-old child with a rapidly increasing left sided proptosis (a, left). Marked enhancement of the retroorbital rhabdomyosarcorna is seen to be distinct from the globe (b, right).
438
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Fig. 7 - Same patient as in Fig. 5, following radiotherapy. There is a marked reduction in the turnout size.
Fig. 8 - Three-year-old child with acute leukaemia showing infiltration of the left optic nerve.
muscle cone because there is no lymphoid tissue behind the anterior orbital septum (Hilal and Trokel, 1977). The CT findings in our patient with leukaemia was a thickened optic nerve which showed no change with contrast medium. There was a slight proptosis (Fig. 8).
larity of the optic nerve. Occasionally an area of calcific density involving a small segment of the optic nerve may be detected (Hilal and Trokel, 1977). Usually the optic nerve cannot be separated from the tumour. The enhancement of the tumour following intravenous iodinated contrast medium is variable and usually only moderate (Hilal and Trokel, 1977). It is important in all patients with optic nerve glioma to search for intracranial extension of the neoplasm. The chiasm must be examined with intravenous contrast in all patients. The tumour mass itself may be visible as well as distortion of the basal cisterns and the lower portion of the third ventricle. In Fig. 9a, a large bulbous optic nerve glioma with intracranial extension involving the optic chiasm is noted. Moderate enhancement of the lesion was observed following the administration of intravenous iodinated contrast medium (Fig. 9b). Fig. 10a, b shows an optic chiasmal glioma in a five-year-old boy. On the precontrast scan (Fig. 10a), there is a large area of low density with peripheral calcification. This lesion caused marked hydrocephalus of the lateral and third ventricles, and after intravenous contrast medium (Fig. 10b) there was marked homogeneous enhancement of the tumour.
Gliomas of the Optic Nerve and Optic Chiasm Optic nerve gliomas constitute 3% of childhood orbital turnouts (Nicholson and Green, 1975)and are most frequently diagnosed between 4 and 10 years of age. The majority are benign astrocytomas and are slow growing and do not metastasise. The morbidity and mortality are due to local enlargement and compression of adjacent neural structures. Evidence of Von Recklinghausen's disease is present in approximately 11% of cases (Porterfield and Zimmerman, 1962). There is typically bulbous enlargement of the orbital portion of the optic nerve and the meninges are markedly thickened. The tumour may extend peripherally towards the eye or centrally towards the brain. The tumour mass is encapsulated within the muscle cone and the globe is displaced axially. Clinically, intraorbital optic nerve gliomas present with proptosis and loss of vision. The intracranial gliomas of the orbital pathway present with loss of vision and signs of raised intracranial pressure. The CT findings include thickening and irregu-
Metastatic Orbital Tumours Orbital metastases in children have been described most frequently in association with neuroblastoma and less frequently with Ewing's sarcoma (Albert et al., 1967)_
THE
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IN PAEDIATRIC
ORBITAL
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439
Fig. 9 (a, left, b, right) Four-year-old child with a left optic nerve glioma showing extensive intracranial extension. Note the marked enhancement in b.
Fig. 10 - Marked homogeneous enhancement in an optic chiasmatic glioma in a three-year-old child (b, right). In the precontrast scan (a, left) there is an area of low density with peripheral calcification in the optic chiasm region. Note the obstructive hydrocephalus.
Orbital metastases generally occur late in the course of neuroblastoma. Initial orbital involvement occurs in less than 5% of cases (Nicholson and Green, 1975). Orbital metastases may however precede detection o f the primary site of tumour origin by as long as nine months (Nicholson and Green, 1975). The metastases may be unilateral or bilateral. Neuroblastomas which most frequently metastasise to the
orbit, arise in the abdomen or pelvis and less frequently in the chest (Albert et aL, 1967). Clinical features of metastatic neuroblastoma to the orbit include spontaneous lid ecchymosis, palpable swelling (often fluctuant) of the adjacent zygomatic bone due to bony metastasis, radiographic evidence o f bone destruction. The CT findings in our patient were of a small high
440 density mass situated behind the significant change after contrast.
CLINICAL RADIOLOGY globe with no
CONCLUSION CT does n o t allow for an absolute histological diagnosis in paediatric orbital turnouts; however, it is of considerable value in the p r e t r e a t m e n t assessm e n t o f the e x t e n t of the tumour. The retro-erbital and intracranial e x t e n s i o n of the t u m o u r are readily assessed, as well as i n v o l v e m e n t o f the b o n y orbit. CT offers a rapid, accurate and non-invasive assessm e n t of the orbit postsurgery and or radiotherapy.
REFERENCES
Mbert, D. M., Rubenstein, R. A. & Scheie, H. G. (1967). Tumour metastases to the eye. Part II. Clinical study in infants and Children. American Journal c~f Ophthalmology, 63, 727. Ambrose, J. A. E., Lloyd, G, A. S. &Wright, J. E. (1974). A
preliminary evaluation of fine matrix computerised axial tomography (EMI scan) in the diagnosis of orbital space occupying lesions. British Journal o f Radiology, 47 (563) 747 -751. Frayer, W. C. & Enterline, H. T. (1959). EmbrYonal rhabdomyosarcomas of the orbit m children and Young adults. Archives of Ophthalmology, 62, 203-210. Friedman, J. & Goldberg, L. (1976). Incidence of retino. blastoma in Bantu of South Africa. British JoUrnal of Ophthalmology, 60, 655. Hilal Sadek, K. & Trokel, Stephen L. (1977). Computerised tomography of the orbit using thin sections. Seminars in Roentgenology, 12 (2), 137 -147. Nicholson, Don H. & Green, Richard W. (1975). Paediatric Ophthalmology, (ed. Robinson, D. Harley), Chap. 33, pp. 923, 930-933, 1023, 1032, 1033, 1039, W. 13. Saunders Co. Porterfield, J. F. & Zimmerman, L. E. (1962). Orbital rhabdomyosarcomas. A clinicopathologic study of 55 cases. Virchows Archiv fiir pathologische Anatomic, 335, 329_ Porterfield, John, F. (1962). Orbital turnouts in children: a report of 214 cases. International Ophthalmology Clin&s: Turnouts of the eye and Adnexa (ed. Zimmerman, Lorenz E.), Vol. 2, No. 2, pp. 319-335.
