1991, The British Journal of Radiology, 64, 847-849 Case reports KARLEN, J. R., PIVER, M. S. & BARLO, J. J., 1975. Melanoma of
the vulva. Obstetrics and Gynaecology, 45, 181-185. KOLSTAD, P., 1986. Melanoma of the vulva. In Clinical Gynaecologic Oncology—The Norwegian Experience, ed. by P. Kolstad (Norwegian University Press, Oslo), pp. 53-55. MORROW, C. P., 1981. Melanoma of the female genital tract. In Gynaecologic Oncology, ed. by M. Cooplesson (Churchill Livingstone, New York), pp. 784-794. MORROW, C. P. & DIASIA, P. J., 1976. Malignant melanoma of
OVERGAARD, J., 1980. Radiation treatment of malignant melanoma. International Journal of Radiation Oncology, Biology, Physics, 6, 41-44. PODRANTZ, K. C , 1983. Melanoma of the vulva—an update. Gynaecologic Oncology, 16, 153-160. STRAUSS, A., DRITISCHILO, A., NATHANSON, L. & PIRO, A. J.,
1981. Radiation therapy of malignant melanomas—an evaluation of clinically used fractionation regimens. Cancer, 47, 1262-1266.
the female genitalia—a clinical analysis. Obstetrical and Gynaecological Survey, 31, 223-271.
Malignant fibrous histiocytoma: an unusual presentation By P. M. Hughes, MRCP, FRCR, I. Zammit-Maempel, MRCP, FRCR, *M. Hughes, FRCS, FRCR and R. J. Johnson, MRCP, FRCR Department of Diagnostic Radiology, Christie Hospital and Holt Radium Institute, Wilmslow Road, Withington, Manchester M20 9BX, UK and *Hope Hospital, Eccles Old Road, Salford, UK {Received November 1990 and in revised form December 1990)
Keywords: Malignant fibrous histiocytoma, Intercranial, Computed tomography
Malignant fibrous histiocytoma (MFH) is the commonest type of adult soft tissue sarcoma (Weiss & Enzinger, 1978). Intracranial MFHs, however, are rare and unreported in children. We report a case of MFH presenting as a posterior fossa mass in a 9-year-old boy with homocystinuria (HCU). This is an unusual presentation and the computed tomography (CT)findingof localized skull vault destruction proved an important differentiating feature from primary posterior fossa tumours. Early diagnosis of MFH is important as primary wide excision of involved bone margins improves prognosis, irrespective of subsequent radiotherapy or adjuvant chemotherapy (Tracy et al, 1984).
and dilatation of the third and lateral ventricles. After intravenous contrast the mass demonstrated homogeneous enhancement and was shown to be well defined and bilobular (Fig. 1). The tumour had invaded and destroyed the adjacent occipital bone and there was extension into the superficial soft tissues (Fig. 2). Surgical exploration revealed a soft tissue mass protruding through the destroyed occipital bone. The posterior fossa
Case report A 9-year-old boy presented with a 4 week history of headaches and vomiting. He had a history of Pyridoxine resistant HCU diagnosed in the neonatal period and had been successfully managed with a low methionine, cystine supplemented diet. On examination there was right sided cerebellar ataxia, sustained nystagmus to rightward gaze but no cranial nerve palsies or papilloedema. The patient's intelligence was normal (IQ was 98), and there was no evidence of lens dislocation or any skeletal manifestations of homocystinuria. The full blood count, erythrocyte sedimentation rate and biochemical profile were normal. Cranial CT revealed an isodense mass in the right cerebellar region, with contralateral displacement of the fourth ventricle Author for correspondence: Dr P. M. Hughes, Department of Diagnostic Radiology, Christie Hospital and Holt Radium Institute. Vol. 64, No. 765
Figure 1. Post-contrast CT scan showing a well defined, bilobular enhancing mass in the right cerebellar region with dilatation of the third and lateral ventricles.
847
Case reports
Figure 3. H&E section showing mixture of histiocytes, fibroblasts and osteoclast type giant cells (object x 20). Figure 2. CT scan at bone settings showing destruction of the right occipital bone and extracranial tumour extension. tumour was well circumscribed and extended both intradurally and extradurally. The pia mater was intact and no cerebellar involvement could be identified. Microscopic examination showed a tumour composed of a random mixture of histiocytes, fibroblasts and osteoclast type giant cells with areas demonstrating a vague storiform (spoked-wheel) pattern (Fig. 3). The fibroblasts and histiocytes displayed some pleomorphism and mitotic activity. A piece of bone showed infiltration by tumour. A thin fibrous pseudo-capsule was present but in areas this appeared infiltrated by tumour. The tumour was considered to be meningeal in origin. The appearances were those of a giant cell tumour and were classified as a giant cell variant of MFH. CT scans of the thorax, abdomen and pelvis performed after histological diagnosis could identify no metastases or distant primary tumour. Following surgical excision localized cranial irradiation was performed and the patient remains well after 6 months. Discussion
Primary MFH is one of the commonest adult soft tissue sarcomas occurring most frequently in the seventh decade and involving the extremities in 70% (Weiss & Enzinger, 1978). Primary intracranial MFHs are rare with only 10 reported cases, all in adults and most occurring following cranial radiotherapy for either gliomas or pituitary tumours (Kepes et al, 1973; Gonzales-Vitale et al, 1976; Lam & Colah, 1979; Kalyanaram et al, 1981; Amendola et al, 1985; Sima et al, 1986). Primary intracranial MFHs occur during middle age, are usually supratentorial in site and invariably arise from the meninges. Cerebral metastases from peripheral MFHs are not uncommon (Espana et al, 1980), have a more varied intracranial distribution than primary tumours and are usually found in more elderly patients. This case is unusual because of the patient's age, the tumour site, its homogeneous enhancement and the presence of localized bony infiltration. Few reviews have considered MFH in children (Cozzutto et al, 1978; Karev, 1979; Tracy et al, 1984), 848
reflecting the paucity of tumours (1-2%) in this group. Several differences have been noted in extremity MFHs in children; girls were more commonly affected in contrast to the 2:1 male predominance in adults, and also the prognosis appeared better with a 100% survival at a median of 4 years (Tracy et al, 1984) in one limited study, compared with 60% 2 year survival in most larger adult series. The differential diagnosis of a paediatric posterior fossa mass most commonly includes medulloblastoma, astrocytoma, ependymoma or metastasis. No other lesion was identifiable in this case and the tumour exhibited features atypical of other primary intracranial tumours. With the exception of metastases, skull vault destruction is not a recognized feature in posterior fossa tumours, although bone erosion has been reported in adults with aggressive supratentorial gliomas. Feldman and Newman (1972) described bony involvement in association with MFH in 25% of cases, of which 75% were thought to represent localized infiltration. The remaining 25% were considered to have arisen primarily from bone. Localized skull base destruction has been documented secondary to a nasopharyngeal MFH (Feldman & Newman, 1972), but never from an intracranial tumour. Calvarial involvement is usually extensive, permeative and unifocal unlike other more common pathologies, such as myeloma and metastases which appear as multifocal well defined lytic foci (Feldman & Newman, 1972). There have been few descriptions of the CT appearances of intracranial MFH (Sima et al, 1986; Simpson et al, 1986; Schrader et al, 1989). The appearances were variable, being either solid or cystic with a nodular component, reflecting, it is thought, the degree of histological differentiation (pleomorphic, storiform, inflammatory, or myxoid) (Katenkamp, 1983). Homogeneous CT enhancement of the intracranial MFH in the present case emphasizes the varied enhancement characteristics of these tumours, as previous reports have only described heterogeneous tumour enhancement. The The British Journal of Radiology, September 1991
1991, The British Journal of Radiology, 64, 849-851 Case reports
suspected dural origin of the MFH in this case is consistent with the other reported cases of primary intracranial MFH. The presence of HCU in association with MFH is likely to be coincidental. HCU is, however, known to cause arterial and venous thrombosis which may lead to bone infarction and this has been associated with MFH (Stoker, 1986). In conclusion MFH is a common adult soft tissue sarcoma which is rarely found in children. Intracranial MFH can occur in children, may enhance homogeneously and should be considered in the differential diagnosis of any meningeal based tumour. Localized bone destruction may prove a helpful differentiating feature from other primary intracranial tumours.
GONZALES-VlTALE, J. C , SLAVIN, R . E. & McQUEEN, D . J.,
1976. Radiation induced intracranial malignant histiocytoma. Cancer, 37, 2960-2963.
fibrous
KALYANARAM, V. P., TARASKA, J. J., FIERER, J. A. & ELWOOD,
P. W., 1981. Malignant fibrous histiocytoma of meninges. Histological, ultrastructural and immuno-histiochemical studies. Journal of Neurosurgery, 55, 957-962. KAREV, A., 1979. Malignant histiocytoma of the arm in a four year old boy. The Hand, 11, 106-107. KATENKAMP, D., 1983. Das maligne fibrose Histiozytom des Weichgewebes. Deutsch. Gesundheitswes., 38, 1633-1640. KEPES, J. J., KEPES, M. & SLOWIK, F., 1973. Fibrous xanthomas
and xanthosarcomas of the meninges and the brain. Ada Neuropathologica, 23, 187-199. LAM, R. M. Y. & COLAH, S. A., 1979. Atypical fibrous histiocytoma with myxoid stroma. A rare lesion arising from dura mater of the brain. Cancer, 43, 237-245. SCHRADER, B., HOLLAND, B. R. & FREIDRICHSEN, C , 1989.
Acknowledgments We would like to thank Dr P. Morris-Jones for permission to report this case, Dr A. Kelsey for reviewing the histology and providing illustrations and Miss M. Robinson for her secretarial assistance. References
Rare case of a primary malignant fibrous histiocytoma of the brain. Neuroradiology, 31, 177-179. SIMA, A. A. F., Ross, R. T., HOAG, G., ROZDILSKY, B. &
DIOCEE, M., 1986. Malignant intracranial fibrous histiocytoma. Histological, ultrastructural and immunohistochemical studies of two cases. Canadian Journal of Neurological Sciences, 13, 138-145.
AMENDOLA, B. E., AMENDOLA, M. A. & MCCLATCHEY, K. D.,
SIMPSON, R. H. W., PHILLIPS, J. I., MILLER, P., HAGEN, D. &
1985. Radiation induced malignant fibrous histiocytoma: a report of five cases including two occurring post whole brain irradiation. Cancer Investigation, 3, 507-513.
ANDERSON, J. E. M., 1986. Intracerebral malignant fibrous histiocytoma: a light and electron microscopic study with immuno-comistochemistry. Clinical Neuropathology, 5, 185-189. STOKER, J. S., 1986. Bone Tumours (2), Malignant Lesions. Diagnostic Radiology, Eds. R. G. Grainger and D. J. Allison, (Churchill Livingstone, London), 1316-1317.
COZZUTTO,
C,
DEBENARDI,
B.
&
GUARINO,
M.,
1978.
Retroperitoneal fibrohistiocytic tumours in children: report of five cases. Cancer, 42, 1350-1363. ESPANA, P., CHANG, P. & WIERNICK, P. H., 1980. Increased
incidence of brain metatases in sarcoma patients. Cancer, 45, 377-379. FELDMAN, F. & NEWMAN, D., 1972. Intra and extraosseous
malignant -fibrous histiocytoma (Malignant Xanthoma). Radiology, 104, 497-508.
Fibrous
TRACY, T., NEIFIELD, J. P., DEMAY, R. M. & SALZBERG, A. M.,
1984. Malignant fibrous histiocytomas in children. Journal of Paediatric Surgery, 19 (1), 81-83. WEISS, S. W. & ENZINGER, F. M., 1978. Malignant fibrous
histiocytoma. Analysis of 200 cases. Cancer, 41, 2250-2266.
Ultrasonic diagnosis of dislocation of the radius in an infant with Down's syndrome By A. C. Lamont, FRCR and * J . J . Dias, M D , FRCS Leicester Royal Infirmary, Infirmary Square, Leicester LE1 5WW, UK and *Glenfield General Hospital, Leicester, UK {Received October 1990 and in revised form December 1990) Keywords: Radial head, Dislocation, Down's syndrome, Ultrasound
The alignment of the capitellum and the radial head is difficult to ascertain from standard radiography because they do not ossify before the age of 9 months. It may therefore not be possible to distinguish between radiohumeral dislocation and a supracondylar epiphyseal fracture in an infant (Dias et al, 1988). We report a case in which dynamic ultrasonic examination provided good definition of dislocation of the radius. Case report An 8-month-old infant with Down's syndrome was presented to the paediatrician when the parents noticed that the Vol. 64, No. 765
left elbow "looked funny" at the time when the child first began to crawl. On examination the elbow was painless and a definite click could be felt when the elbow was manipulated. The head of the radius was unstable and was felt to dislocate posteriorly. The remainder of the arm appeared normal and there was no evidence of a major peripheral nerve injury. Radiographs showed no ossification of either the capitellum or the radial head and revealed normal alignment. Some deformity of the radial neck with posterior "pointing" was present (Fig. 1). Ultrasonic examination of the elbow was performed using the 7.5 MHz curved linear array of an Aloka-630 diagnostic ultrasound machine. The elbow was scanned longitudinally
849
the vulva. Obstetrics and Gynaecology, 45, 181-185. KOLSTAD, P., 1986. Melanoma of the vulva. In Clinical Gynaecologic Oncology—The Norwegian Experience, ed. by P. Kolstad (Norwegian University Press, Oslo), pp. 53-55. MORROW, C. P., 1981. Melanoma of the female genital tract. In Gynaecologic Oncology, ed. by M. Cooplesson (Churchill Livingstone, New York), pp. 784-794. MORROW, C. P. & DIASIA, P. J., 1976. Malignant melanoma of
OVERGAARD, J., 1980. Radiation treatment of malignant melanoma. International Journal of Radiation Oncology, Biology, Physics, 6, 41-44. PODRANTZ, K. C , 1983. Melanoma of the vulva—an update. Gynaecologic Oncology, 16, 153-160. STRAUSS, A., DRITISCHILO, A., NATHANSON, L. & PIRO, A. J.,
1981. Radiation therapy of malignant melanomas—an evaluation of clinically used fractionation regimens. Cancer, 47, 1262-1266.
the female genitalia—a clinical analysis. Obstetrical and Gynaecological Survey, 31, 223-271.
Malignant fibrous histiocytoma: an unusual presentation By P. M. Hughes, MRCP, FRCR, I. Zammit-Maempel, MRCP, FRCR, *M. Hughes, FRCS, FRCR and R. J. Johnson, MRCP, FRCR Department of Diagnostic Radiology, Christie Hospital and Holt Radium Institute, Wilmslow Road, Withington, Manchester M20 9BX, UK and *Hope Hospital, Eccles Old Road, Salford, UK {Received November 1990 and in revised form December 1990)
Keywords: Malignant fibrous histiocytoma, Intercranial, Computed tomography
Malignant fibrous histiocytoma (MFH) is the commonest type of adult soft tissue sarcoma (Weiss & Enzinger, 1978). Intracranial MFHs, however, are rare and unreported in children. We report a case of MFH presenting as a posterior fossa mass in a 9-year-old boy with homocystinuria (HCU). This is an unusual presentation and the computed tomography (CT)findingof localized skull vault destruction proved an important differentiating feature from primary posterior fossa tumours. Early diagnosis of MFH is important as primary wide excision of involved bone margins improves prognosis, irrespective of subsequent radiotherapy or adjuvant chemotherapy (Tracy et al, 1984).
and dilatation of the third and lateral ventricles. After intravenous contrast the mass demonstrated homogeneous enhancement and was shown to be well defined and bilobular (Fig. 1). The tumour had invaded and destroyed the adjacent occipital bone and there was extension into the superficial soft tissues (Fig. 2). Surgical exploration revealed a soft tissue mass protruding through the destroyed occipital bone. The posterior fossa
Case report A 9-year-old boy presented with a 4 week history of headaches and vomiting. He had a history of Pyridoxine resistant HCU diagnosed in the neonatal period and had been successfully managed with a low methionine, cystine supplemented diet. On examination there was right sided cerebellar ataxia, sustained nystagmus to rightward gaze but no cranial nerve palsies or papilloedema. The patient's intelligence was normal (IQ was 98), and there was no evidence of lens dislocation or any skeletal manifestations of homocystinuria. The full blood count, erythrocyte sedimentation rate and biochemical profile were normal. Cranial CT revealed an isodense mass in the right cerebellar region, with contralateral displacement of the fourth ventricle Author for correspondence: Dr P. M. Hughes, Department of Diagnostic Radiology, Christie Hospital and Holt Radium Institute. Vol. 64, No. 765
Figure 1. Post-contrast CT scan showing a well defined, bilobular enhancing mass in the right cerebellar region with dilatation of the third and lateral ventricles.
847
Case reports
Figure 3. H&E section showing mixture of histiocytes, fibroblasts and osteoclast type giant cells (object x 20). Figure 2. CT scan at bone settings showing destruction of the right occipital bone and extracranial tumour extension. tumour was well circumscribed and extended both intradurally and extradurally. The pia mater was intact and no cerebellar involvement could be identified. Microscopic examination showed a tumour composed of a random mixture of histiocytes, fibroblasts and osteoclast type giant cells with areas demonstrating a vague storiform (spoked-wheel) pattern (Fig. 3). The fibroblasts and histiocytes displayed some pleomorphism and mitotic activity. A piece of bone showed infiltration by tumour. A thin fibrous pseudo-capsule was present but in areas this appeared infiltrated by tumour. The tumour was considered to be meningeal in origin. The appearances were those of a giant cell tumour and were classified as a giant cell variant of MFH. CT scans of the thorax, abdomen and pelvis performed after histological diagnosis could identify no metastases or distant primary tumour. Following surgical excision localized cranial irradiation was performed and the patient remains well after 6 months. Discussion
Primary MFH is one of the commonest adult soft tissue sarcomas occurring most frequently in the seventh decade and involving the extremities in 70% (Weiss & Enzinger, 1978). Primary intracranial MFHs are rare with only 10 reported cases, all in adults and most occurring following cranial radiotherapy for either gliomas or pituitary tumours (Kepes et al, 1973; Gonzales-Vitale et al, 1976; Lam & Colah, 1979; Kalyanaram et al, 1981; Amendola et al, 1985; Sima et al, 1986). Primary intracranial MFHs occur during middle age, are usually supratentorial in site and invariably arise from the meninges. Cerebral metastases from peripheral MFHs are not uncommon (Espana et al, 1980), have a more varied intracranial distribution than primary tumours and are usually found in more elderly patients. This case is unusual because of the patient's age, the tumour site, its homogeneous enhancement and the presence of localized bony infiltration. Few reviews have considered MFH in children (Cozzutto et al, 1978; Karev, 1979; Tracy et al, 1984), 848
reflecting the paucity of tumours (1-2%) in this group. Several differences have been noted in extremity MFHs in children; girls were more commonly affected in contrast to the 2:1 male predominance in adults, and also the prognosis appeared better with a 100% survival at a median of 4 years (Tracy et al, 1984) in one limited study, compared with 60% 2 year survival in most larger adult series. The differential diagnosis of a paediatric posterior fossa mass most commonly includes medulloblastoma, astrocytoma, ependymoma or metastasis. No other lesion was identifiable in this case and the tumour exhibited features atypical of other primary intracranial tumours. With the exception of metastases, skull vault destruction is not a recognized feature in posterior fossa tumours, although bone erosion has been reported in adults with aggressive supratentorial gliomas. Feldman and Newman (1972) described bony involvement in association with MFH in 25% of cases, of which 75% were thought to represent localized infiltration. The remaining 25% were considered to have arisen primarily from bone. Localized skull base destruction has been documented secondary to a nasopharyngeal MFH (Feldman & Newman, 1972), but never from an intracranial tumour. Calvarial involvement is usually extensive, permeative and unifocal unlike other more common pathologies, such as myeloma and metastases which appear as multifocal well defined lytic foci (Feldman & Newman, 1972). There have been few descriptions of the CT appearances of intracranial MFH (Sima et al, 1986; Simpson et al, 1986; Schrader et al, 1989). The appearances were variable, being either solid or cystic with a nodular component, reflecting, it is thought, the degree of histological differentiation (pleomorphic, storiform, inflammatory, or myxoid) (Katenkamp, 1983). Homogeneous CT enhancement of the intracranial MFH in the present case emphasizes the varied enhancement characteristics of these tumours, as previous reports have only described heterogeneous tumour enhancement. The The British Journal of Radiology, September 1991
1991, The British Journal of Radiology, 64, 849-851 Case reports
suspected dural origin of the MFH in this case is consistent with the other reported cases of primary intracranial MFH. The presence of HCU in association with MFH is likely to be coincidental. HCU is, however, known to cause arterial and venous thrombosis which may lead to bone infarction and this has been associated with MFH (Stoker, 1986). In conclusion MFH is a common adult soft tissue sarcoma which is rarely found in children. Intracranial MFH can occur in children, may enhance homogeneously and should be considered in the differential diagnosis of any meningeal based tumour. Localized bone destruction may prove a helpful differentiating feature from other primary intracranial tumours.
GONZALES-VlTALE, J. C , SLAVIN, R . E. & McQUEEN, D . J.,
1976. Radiation induced intracranial malignant histiocytoma. Cancer, 37, 2960-2963.
fibrous
KALYANARAM, V. P., TARASKA, J. J., FIERER, J. A. & ELWOOD,
P. W., 1981. Malignant fibrous histiocytoma of meninges. Histological, ultrastructural and immuno-histiochemical studies. Journal of Neurosurgery, 55, 957-962. KAREV, A., 1979. Malignant histiocytoma of the arm in a four year old boy. The Hand, 11, 106-107. KATENKAMP, D., 1983. Das maligne fibrose Histiozytom des Weichgewebes. Deutsch. Gesundheitswes., 38, 1633-1640. KEPES, J. J., KEPES, M. & SLOWIK, F., 1973. Fibrous xanthomas
and xanthosarcomas of the meninges and the brain. Ada Neuropathologica, 23, 187-199. LAM, R. M. Y. & COLAH, S. A., 1979. Atypical fibrous histiocytoma with myxoid stroma. A rare lesion arising from dura mater of the brain. Cancer, 43, 237-245. SCHRADER, B., HOLLAND, B. R. & FREIDRICHSEN, C , 1989.
Acknowledgments We would like to thank Dr P. Morris-Jones for permission to report this case, Dr A. Kelsey for reviewing the histology and providing illustrations and Miss M. Robinson for her secretarial assistance. References
Rare case of a primary malignant fibrous histiocytoma of the brain. Neuroradiology, 31, 177-179. SIMA, A. A. F., Ross, R. T., HOAG, G., ROZDILSKY, B. &
DIOCEE, M., 1986. Malignant intracranial fibrous histiocytoma. Histological, ultrastructural and immunohistochemical studies of two cases. Canadian Journal of Neurological Sciences, 13, 138-145.
AMENDOLA, B. E., AMENDOLA, M. A. & MCCLATCHEY, K. D.,
SIMPSON, R. H. W., PHILLIPS, J. I., MILLER, P., HAGEN, D. &
1985. Radiation induced malignant fibrous histiocytoma: a report of five cases including two occurring post whole brain irradiation. Cancer Investigation, 3, 507-513.
ANDERSON, J. E. M., 1986. Intracerebral malignant fibrous histiocytoma: a light and electron microscopic study with immuno-comistochemistry. Clinical Neuropathology, 5, 185-189. STOKER, J. S., 1986. Bone Tumours (2), Malignant Lesions. Diagnostic Radiology, Eds. R. G. Grainger and D. J. Allison, (Churchill Livingstone, London), 1316-1317.
COZZUTTO,
C,
DEBENARDI,
B.
&
GUARINO,
M.,
1978.
Retroperitoneal fibrohistiocytic tumours in children: report of five cases. Cancer, 42, 1350-1363. ESPANA, P., CHANG, P. & WIERNICK, P. H., 1980. Increased
incidence of brain metatases in sarcoma patients. Cancer, 45, 377-379. FELDMAN, F. & NEWMAN, D., 1972. Intra and extraosseous
malignant -fibrous histiocytoma (Malignant Xanthoma). Radiology, 104, 497-508.
Fibrous
TRACY, T., NEIFIELD, J. P., DEMAY, R. M. & SALZBERG, A. M.,
1984. Malignant fibrous histiocytomas in children. Journal of Paediatric Surgery, 19 (1), 81-83. WEISS, S. W. & ENZINGER, F. M., 1978. Malignant fibrous
histiocytoma. Analysis of 200 cases. Cancer, 41, 2250-2266.
Ultrasonic diagnosis of dislocation of the radius in an infant with Down's syndrome By A. C. Lamont, FRCR and * J . J . Dias, M D , FRCS Leicester Royal Infirmary, Infirmary Square, Leicester LE1 5WW, UK and *Glenfield General Hospital, Leicester, UK {Received October 1990 and in revised form December 1990) Keywords: Radial head, Dislocation, Down's syndrome, Ultrasound
The alignment of the capitellum and the radial head is difficult to ascertain from standard radiography because they do not ossify before the age of 9 months. It may therefore not be possible to distinguish between radiohumeral dislocation and a supracondylar epiphyseal fracture in an infant (Dias et al, 1988). We report a case in which dynamic ultrasonic examination provided good definition of dislocation of the radius. Case report An 8-month-old infant with Down's syndrome was presented to the paediatrician when the parents noticed that the Vol. 64, No. 765
left elbow "looked funny" at the time when the child first began to crawl. On examination the elbow was painless and a definite click could be felt when the elbow was manipulated. The head of the radius was unstable and was felt to dislocate posteriorly. The remainder of the arm appeared normal and there was no evidence of a major peripheral nerve injury. Radiographs showed no ossification of either the capitellum or the radial head and revealed normal alignment. Some deformity of the radial neck with posterior "pointing" was present (Fig. 1). Ultrasonic examination of the elbow was performed using the 7.5 MHz curved linear array of an Aloka-630 diagnostic ultrasound machine. The elbow was scanned longitudinally
849
