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MR Imaging of Intramedullary Spinal Cysticercosis:A Report of Two Cases
Clinical Radiology (2000) 55, 311–325
Case Reports doi:10.1053/crad.1999.0080, available online at http://www.idealibrary.com on
MR Imaging of Intramedullary Spinal Cysticercosis: A Report of Two Cases V. GAUR, R. K. GUPT A, R . DE V, M. K. KAT HURIA, M. HUSAIN Department of Radiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences and Department of Neurosurgery, KG Medical College, Lucknow, India
Cysticercosis is the commonest parasitic disease to affect the central nervous system (CNS). Neurocysticercosis may be meningobasal (30%), parenchymal (20%), intraventricular (17%), intraspinal (1%) or mixed (23%) [1]. Parasitic infestation of the spinal cord may result in the formation of an intramedullary cyst. Magnetic resonance imaging (MRI) features of cranial cysticercosis are well documented and are characteristic of the disease [2,3]. Isolated intramedullary cysticercosis is rare. MRI features have been described in an occasional case of intramedullary cysticercosis [4]. We present MRI features in two cases of isolated intramedullary spinal cysticercosis and its resolution on serial studies with albendazole therapy.
METHODS
MRI of the spine was performed on a 2T super conducting system (Magnetom SP, Siemens, Erlangen, Germany) operating at 1.5 T, using an oval spine coil. T1-weighted (TR/TE/n ¼ 550/ 15/3), proton density (PD) and T2-weighted (TR/TE/n ¼ 2200/ 20,80/1) spin-echo (SE) images were obtained in the sagittal plane with a slice thickness of 3 mm, an interslice gap of 0.3 mm and a 256 × 256 matrix. Post-contrast T1-weighted images were obtained after injecting Gd-DTPA in the dose of 0.1 mmol/kg bodyweight in one patient. Brain MRI was performed using a circularly polarized head coil in both patients with T1 (TR/TE/ n ¼ 500/15/3), PD and T2-weighted (TR/TE/n ¼ 2200/20,80/1) SE images in the axial plane with a slice thickness of 5 mm, an interslice gap of 0.5 mm and a 192 × 256 matrix. CASE REPORTS
Case 1 A 22-year-old woman presented with paraparesis and urinary retention of gradual onset, for a period of 4 months. She was in good health prior to the onset of this illness. Motor system examination revealed a normal muscle Author for correspondence: Dr R.K. Gupta, Additional Professor, Department of Radiology, SGPIGMS, Lucknow 226 014, (UP) India. 0009-9260/00/040311+15 $35.00/0
bulk with grade zero power in both lower limbs. Knee and ankle jerks were exaggerated, with plantars being bilaterally upgoing. Pain, touch and temperature were lost below the T8 dermatome. Investigations revealed haemoglobin 11 gm%, total leucocytes count 12000/mm3. Differential leucocyte count showed presence of 18% eosinophils. Blood urea, serum creatinine and blood sugar were normal. Routine cerebrospinal fluid examination revealed three to four leukocytes with normal proteins and sugars. Cerebro-spinal fluid (CSF) culture for M tuberculosis was negative. CSF enzyme-linked immunosorbent assay (ELISA) for cysticercus antibodies was strongly positive. Chest radiography was normal and radiography of both the upper and lower limb muscles did not reveal any calcified lesion. MRI of the dorsal spine showed a small intramedullary hypointense cyst at the D8 level with a peripheral isointense rim on T1- and PD-weighted images. It appeared hyperintense with a peripheral isointense rim on T2weighted images. It was associated with extensive oedema of the spinal cord both, caudal and rostral to the lesion (Fig. 1). The brain did not show any focal or diffuse abnormality. The patient was subsequently kept on albendazole and steroid therapy for 8 days. She made a complete recovery following the 3 months of therapy and a repeat MR showed small residual lesion (Fig. 1d) which disappeared completely after another 2 months without any further treatment.
Case 2 A 27-year-old woman presented with tingling and burning sensations in the back for the last 5 months followed by sensation of numbness, starting in the right lower limb and then involving the left lower limb over a period of 3 months. There had been gradual progressive weakness in both lower limbs for the last 2 months. Subsequently, she lost control over the bladder and bowel functions. Neurological examination revealed increased muscle tone along with grade zero power in both lower limbs. Knee and ankle jerks were exaggerated and plantars were bilaterally upgoing. There was loss of pain, touch and temperature below the T6 spinal level. Haemogram and routine blood chemistry were normal. MRI revealed a well-defined intramedullary cyst opposite the D5 –D6 vertebral bodies. The cyst was hypointense on T1- and PD-weighted images. T2-weighted images showed the cyst to be hyperintense with a peripheral isointense rim. Post-contrast medium T1-weighted images showed peripheral rim enhancement. The cystic lesion was associated with rostral as well as caudal perifocal oedema (Fig. 2). Radiography of both upper limbs, lower limbs and chest did not reveal any calcified lesions. Routine CSF examination showed 1–2 leucocytes with normal sugar and proteins. CSF ELISA was positive for cysticercus antibodies. MRI of the brain was also performed and was normal. The patient was kept on albendazole and steroid therapy for 2 months and a repeat MRI after 6 months showed complete regression of the lesion. This regression was associated with almost complete clinical recovery. However, the bladder control was only partially regained. The patient was subsequently lost to follow-up. q 2000 The Royal College of Radiologists
312
CLINICAL RADIOLOGY
(a)
(b)
(c)
(d)
(e)
Fig. 1 – Patient 1: intramedullary cyst at the D8 vertebra. T2-weighted midsagittal image (a) shows a cyst with a hyperintense centre and isointense rim which, on PD- (b) and T1- (c) weighted images appears hypointense in the centre and isointense to the adjoining spinal cord in the periphery. Note the hyperintense oedema rostral and caudal to the lesion on the T2-weighted and PD-weighted images (a, b). (d) Repeat T2-weighted image after 3 months of specific treatment shows small residual lesion. (e) Repeat T2-weighted image after another 2 months shows no residual lesion.
313
CASE REPORTS
(a)
(b)
(c)
Fig. 2 – Patient 2: intramedullary cyst at the D5/D6 vertebrae. (a, b) T2weighted mid-sagittal image (a) shows a hyperintense cyst with small peripheral hypointensity in the spinal cord which appears hypointense with peripheral isointensity on T1-weighted images. (b) Perifocal oedema in the spinal cord is seen on T2-weighted images. (c) Post-contrast T1-weighted image shows enhancement around the cyst wall, and in the adjoining cord rostral and caudal to the cyst.
DISCUSSION
The pathognomonic MRI feature of neurocysticercosis is the presence of cyst with an eccentric mural nodule representing the scolex [2,3]. The cyst shows an intensity pattern identical to CSF, the mural nodule is hyper- to isointense on T1-weighted images and hypointense on T2-weighted images [2,3]. Cysticercus with the onset of degeneration most commonly presents
as encapsulated lesion with surrounding oedema. It is characterized on T2-weighted images by an iso- to hypointense rim with a hyperintense core and hyperintense perifocal oedema. The rim and core are iso- and hypointense on corresponding T1-weighted images [3,6,7]. Intracranial neurocysticercosis can also be generalized to spinal cord involvement [5]. An isolated case of intramedullary spinal cysticercosis, described by Castillo et al., demonstrated
314
CLINICAL RADIOLOGY
the cyst in the thoracic spine with no evidence of scolex. The scolex was subsequently not demonstrated on histopathology in the patient [4]. In both our cases of intramedullary spinal cysticercosis, a hyperintense core with an isointense rim associated with perifocal oedema were observed on T2-weighted images. The findings are similar to the features described in previous studies of cranial cysticercus lesions [6,7]. Approximately 50% of the cases reported in the literature were found to harbour parasites in other sites, primarily the brain (30%) and muscle tissues. Isolated involvement of the spinal cord is extremely rare. In our cases, the brain and muscles were normal on imaging, while isolated involvement of dorsal spinal cord was seen. Intramedullary spinal cysticercosis usually occurs as a single lesion and involves the dorsal cord in majority of cases, suggesting that haematogenous dissemination is a more probable mechanism for spread of the disease [8]. The differential diagnosis of intramedullary cysticercosis usually includes granulomas of other aetiology, most commonly of tuberculous origin. The findings of a purely cystic lesion with a CSF intensity pattern, a positive CSF ELISA for cysticercus antibodies and a response to albendazole therapy should help in differentiation of other granulomas from cysticercus granuloma.
In conclusion, we suggest that a differential diagnosis of cysticercosis should be considered in intramedullary cystic lesions, whether single or multiple, even in the absence of any lesion in the brain, especially in patients from endemic regions. REFERENCES 1 Rodacki MA, Detoni XA, Teixeira WR, Boer VH, Oliveira GG. CT features of cellulosae and racemosus neurocysticercosis. J Comput Assist Tomogr 1989;13:1013–1016. 2 Jena A, Sanchetee PC, Gupta RK, Khushu S, Chandra R, Lakshmipathi N. Cysticercosis of the brain shown by magnetic resonance imaging. Clin Radiol 1988;39:542–546. 3 Lotz J, Hewlett R, Alheit B, Bowen R. Neurocysticercosis: correlative pathomorphology and MR imaging. Neuroradiology 1988;30:35–41. 4 Castillo M, Quencer RM, Post MJD. MR of intramedullary spinal cysticercosis. Am J Neuroradiol 1988;9:393–395. 5 Jeffrey LC, John JA. Magnetic resonance imaging of neurocysticercosis. Topics Magn Res Imag 1994;6:59–68. 6 Zee CS, Segall HD, Boswel W, et al. MR imaging of neurocysticercosis. J Comput Assist Tomogr 1988;12:927–934. 7 Rajshekhar V, Chandy MJ. Comparative study of CT and MRI in patients with seizures and a solitary cerebral cysticercus granuloma. Neuroradiology 1996;38:542–546. 8 Souza LQ, Filho AP, Collegaro D, DeFaria LL. Intramedullary cystercerocsis case report, literature review and comments on pathogenesis. J Neurol Sci 1975;26:61–70.
doi:10.1053/crad.1999.0076, available online at http://www.idealibrary.com on
Metastases to the Liver from Extraskeletal Myxoid Chondrosarcoma and Successful Treatment with Percutaneous Ethanol Injection J. M . R Y A N * , D. E . DUPUY†, M. P IT MA N ‡ , G. W . B O LA N D * , P. F. H A H N * , P. R . MU E L L E R * Departments of *Abdominal and Interventional Radiology, †Musculoskeletal Radiology and ‡Cytology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, U.S.A.
Extraskeletal myxoid chondrosarcoma (EMC), is a rare soft tissue tumour associated with a more variable outcome than conventional chondrosarcoma of bone [1]. A patient with EMC who presented to our department with liver metastases was offered experimental treatment with percutaneous ethanol injection (PEI). We describe both the computed tomographic (CT) and magnetic resonance (MR) appearances of the metastases and their treatment with PEI. Response of the treated metastases 1 year after treatment is described. To the best of our knowledge, neither metastases to the liver from extraskeletal myxoid chondrosarcoma nor PEI therapy of this lesion have been previously described. This case is instructive in providing a new treatment option for patients with hepatic metastases or Author for correspondence: J. Mark Ryan MB, FRCR, FFRRCSI, Division of Abdominal and Interventional Radiology, White 220, Department of Radiology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, U.S.A.
inoperable primary tumour, not only from EMC but perhaps also for other myxoid or soft sarcomatous tumours.
CASE REPORT A 50-year-old man presented with an enlarging buttock mass over an 8-month period. An MR examination of the lesion showed a wellcircumscribed, heterogeneous mass involving the right gluteal region and hamstring compartment of the thigh. The mass was of low signal intensity on SE T1-weighted imaging, with heterogeneous appearances on SE T2 weighted imaging with predominant areas of high signal intensity (Fig. 1). The lesion demonstrated heterogeneous enhancement following administration of 40 ml intravenous gadolinium (Magnevist, Berlex Laboratories, NJ, U.S.A.). Percutaneous biopsy of the buttock lesion revealed a highly cellular, myxoid sarcoma composed of small stellate cells resembling immature chondroblasts. Immunohistochemical stains demonstrated an unusual staining pattern positive for keratin, epithelial membrane antigen, actin and desmin, in addition to the typical vimentin and S100 positivity. Electron q 2000 The Royal College of Radiologists
Case Reports doi:10.1053/crad.1999.0080, available online at http://www.idealibrary.com on
MR Imaging of Intramedullary Spinal Cysticercosis: A Report of Two Cases V. GAUR, R. K. GUPT A, R . DE V, M. K. KAT HURIA, M. HUSAIN Department of Radiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences and Department of Neurosurgery, KG Medical College, Lucknow, India
Cysticercosis is the commonest parasitic disease to affect the central nervous system (CNS). Neurocysticercosis may be meningobasal (30%), parenchymal (20%), intraventricular (17%), intraspinal (1%) or mixed (23%) [1]. Parasitic infestation of the spinal cord may result in the formation of an intramedullary cyst. Magnetic resonance imaging (MRI) features of cranial cysticercosis are well documented and are characteristic of the disease [2,3]. Isolated intramedullary cysticercosis is rare. MRI features have been described in an occasional case of intramedullary cysticercosis [4]. We present MRI features in two cases of isolated intramedullary spinal cysticercosis and its resolution on serial studies with albendazole therapy.
METHODS
MRI of the spine was performed on a 2T super conducting system (Magnetom SP, Siemens, Erlangen, Germany) operating at 1.5 T, using an oval spine coil. T1-weighted (TR/TE/n ¼ 550/ 15/3), proton density (PD) and T2-weighted (TR/TE/n ¼ 2200/ 20,80/1) spin-echo (SE) images were obtained in the sagittal plane with a slice thickness of 3 mm, an interslice gap of 0.3 mm and a 256 × 256 matrix. Post-contrast T1-weighted images were obtained after injecting Gd-DTPA in the dose of 0.1 mmol/kg bodyweight in one patient. Brain MRI was performed using a circularly polarized head coil in both patients with T1 (TR/TE/ n ¼ 500/15/3), PD and T2-weighted (TR/TE/n ¼ 2200/20,80/1) SE images in the axial plane with a slice thickness of 5 mm, an interslice gap of 0.5 mm and a 192 × 256 matrix. CASE REPORTS
Case 1 A 22-year-old woman presented with paraparesis and urinary retention of gradual onset, for a period of 4 months. She was in good health prior to the onset of this illness. Motor system examination revealed a normal muscle Author for correspondence: Dr R.K. Gupta, Additional Professor, Department of Radiology, SGPIGMS, Lucknow 226 014, (UP) India. 0009-9260/00/040311+15 $35.00/0
bulk with grade zero power in both lower limbs. Knee and ankle jerks were exaggerated, with plantars being bilaterally upgoing. Pain, touch and temperature were lost below the T8 dermatome. Investigations revealed haemoglobin 11 gm%, total leucocytes count 12000/mm3. Differential leucocyte count showed presence of 18% eosinophils. Blood urea, serum creatinine and blood sugar were normal. Routine cerebrospinal fluid examination revealed three to four leukocytes with normal proteins and sugars. Cerebro-spinal fluid (CSF) culture for M tuberculosis was negative. CSF enzyme-linked immunosorbent assay (ELISA) for cysticercus antibodies was strongly positive. Chest radiography was normal and radiography of both the upper and lower limb muscles did not reveal any calcified lesion. MRI of the dorsal spine showed a small intramedullary hypointense cyst at the D8 level with a peripheral isointense rim on T1- and PD-weighted images. It appeared hyperintense with a peripheral isointense rim on T2weighted images. It was associated with extensive oedema of the spinal cord both, caudal and rostral to the lesion (Fig. 1). The brain did not show any focal or diffuse abnormality. The patient was subsequently kept on albendazole and steroid therapy for 8 days. She made a complete recovery following the 3 months of therapy and a repeat MR showed small residual lesion (Fig. 1d) which disappeared completely after another 2 months without any further treatment.
Case 2 A 27-year-old woman presented with tingling and burning sensations in the back for the last 5 months followed by sensation of numbness, starting in the right lower limb and then involving the left lower limb over a period of 3 months. There had been gradual progressive weakness in both lower limbs for the last 2 months. Subsequently, she lost control over the bladder and bowel functions. Neurological examination revealed increased muscle tone along with grade zero power in both lower limbs. Knee and ankle jerks were exaggerated and plantars were bilaterally upgoing. There was loss of pain, touch and temperature below the T6 spinal level. Haemogram and routine blood chemistry were normal. MRI revealed a well-defined intramedullary cyst opposite the D5 –D6 vertebral bodies. The cyst was hypointense on T1- and PD-weighted images. T2-weighted images showed the cyst to be hyperintense with a peripheral isointense rim. Post-contrast medium T1-weighted images showed peripheral rim enhancement. The cystic lesion was associated with rostral as well as caudal perifocal oedema (Fig. 2). Radiography of both upper limbs, lower limbs and chest did not reveal any calcified lesions. Routine CSF examination showed 1–2 leucocytes with normal sugar and proteins. CSF ELISA was positive for cysticercus antibodies. MRI of the brain was also performed and was normal. The patient was kept on albendazole and steroid therapy for 2 months and a repeat MRI after 6 months showed complete regression of the lesion. This regression was associated with almost complete clinical recovery. However, the bladder control was only partially regained. The patient was subsequently lost to follow-up. q 2000 The Royal College of Radiologists
312
CLINICAL RADIOLOGY
(a)
(b)
(c)
(d)
(e)
Fig. 1 – Patient 1: intramedullary cyst at the D8 vertebra. T2-weighted midsagittal image (a) shows a cyst with a hyperintense centre and isointense rim which, on PD- (b) and T1- (c) weighted images appears hypointense in the centre and isointense to the adjoining spinal cord in the periphery. Note the hyperintense oedema rostral and caudal to the lesion on the T2-weighted and PD-weighted images (a, b). (d) Repeat T2-weighted image after 3 months of specific treatment shows small residual lesion. (e) Repeat T2-weighted image after another 2 months shows no residual lesion.
313
CASE REPORTS
(a)
(b)
(c)
Fig. 2 – Patient 2: intramedullary cyst at the D5/D6 vertebrae. (a, b) T2weighted mid-sagittal image (a) shows a hyperintense cyst with small peripheral hypointensity in the spinal cord which appears hypointense with peripheral isointensity on T1-weighted images. (b) Perifocal oedema in the spinal cord is seen on T2-weighted images. (c) Post-contrast T1-weighted image shows enhancement around the cyst wall, and in the adjoining cord rostral and caudal to the cyst.
DISCUSSION
The pathognomonic MRI feature of neurocysticercosis is the presence of cyst with an eccentric mural nodule representing the scolex [2,3]. The cyst shows an intensity pattern identical to CSF, the mural nodule is hyper- to isointense on T1-weighted images and hypointense on T2-weighted images [2,3]. Cysticercus with the onset of degeneration most commonly presents
as encapsulated lesion with surrounding oedema. It is characterized on T2-weighted images by an iso- to hypointense rim with a hyperintense core and hyperintense perifocal oedema. The rim and core are iso- and hypointense on corresponding T1-weighted images [3,6,7]. Intracranial neurocysticercosis can also be generalized to spinal cord involvement [5]. An isolated case of intramedullary spinal cysticercosis, described by Castillo et al., demonstrated
314
CLINICAL RADIOLOGY
the cyst in the thoracic spine with no evidence of scolex. The scolex was subsequently not demonstrated on histopathology in the patient [4]. In both our cases of intramedullary spinal cysticercosis, a hyperintense core with an isointense rim associated with perifocal oedema were observed on T2-weighted images. The findings are similar to the features described in previous studies of cranial cysticercus lesions [6,7]. Approximately 50% of the cases reported in the literature were found to harbour parasites in other sites, primarily the brain (30%) and muscle tissues. Isolated involvement of the spinal cord is extremely rare. In our cases, the brain and muscles were normal on imaging, while isolated involvement of dorsal spinal cord was seen. Intramedullary spinal cysticercosis usually occurs as a single lesion and involves the dorsal cord in majority of cases, suggesting that haematogenous dissemination is a more probable mechanism for spread of the disease [8]. The differential diagnosis of intramedullary cysticercosis usually includes granulomas of other aetiology, most commonly of tuberculous origin. The findings of a purely cystic lesion with a CSF intensity pattern, a positive CSF ELISA for cysticercus antibodies and a response to albendazole therapy should help in differentiation of other granulomas from cysticercus granuloma.
In conclusion, we suggest that a differential diagnosis of cysticercosis should be considered in intramedullary cystic lesions, whether single or multiple, even in the absence of any lesion in the brain, especially in patients from endemic regions. REFERENCES 1 Rodacki MA, Detoni XA, Teixeira WR, Boer VH, Oliveira GG. CT features of cellulosae and racemosus neurocysticercosis. J Comput Assist Tomogr 1989;13:1013–1016. 2 Jena A, Sanchetee PC, Gupta RK, Khushu S, Chandra R, Lakshmipathi N. Cysticercosis of the brain shown by magnetic resonance imaging. Clin Radiol 1988;39:542–546. 3 Lotz J, Hewlett R, Alheit B, Bowen R. Neurocysticercosis: correlative pathomorphology and MR imaging. Neuroradiology 1988;30:35–41. 4 Castillo M, Quencer RM, Post MJD. MR of intramedullary spinal cysticercosis. Am J Neuroradiol 1988;9:393–395. 5 Jeffrey LC, John JA. Magnetic resonance imaging of neurocysticercosis. Topics Magn Res Imag 1994;6:59–68. 6 Zee CS, Segall HD, Boswel W, et al. MR imaging of neurocysticercosis. J Comput Assist Tomogr 1988;12:927–934. 7 Rajshekhar V, Chandy MJ. Comparative study of CT and MRI in patients with seizures and a solitary cerebral cysticercus granuloma. Neuroradiology 1996;38:542–546. 8 Souza LQ, Filho AP, Collegaro D, DeFaria LL. Intramedullary cystercerocsis case report, literature review and comments on pathogenesis. J Neurol Sci 1975;26:61–70.
doi:10.1053/crad.1999.0076, available online at http://www.idealibrary.com on
Metastases to the Liver from Extraskeletal Myxoid Chondrosarcoma and Successful Treatment with Percutaneous Ethanol Injection J. M . R Y A N * , D. E . DUPUY†, M. P IT MA N ‡ , G. W . B O LA N D * , P. F. H A H N * , P. R . MU E L L E R * Departments of *Abdominal and Interventional Radiology, †Musculoskeletal Radiology and ‡Cytology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, U.S.A.
Extraskeletal myxoid chondrosarcoma (EMC), is a rare soft tissue tumour associated with a more variable outcome than conventional chondrosarcoma of bone [1]. A patient with EMC who presented to our department with liver metastases was offered experimental treatment with percutaneous ethanol injection (PEI). We describe both the computed tomographic (CT) and magnetic resonance (MR) appearances of the metastases and their treatment with PEI. Response of the treated metastases 1 year after treatment is described. To the best of our knowledge, neither metastases to the liver from extraskeletal myxoid chondrosarcoma nor PEI therapy of this lesion have been previously described. This case is instructive in providing a new treatment option for patients with hepatic metastases or Author for correspondence: J. Mark Ryan MB, FRCR, FFRRCSI, Division of Abdominal and Interventional Radiology, White 220, Department of Radiology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, U.S.A.
inoperable primary tumour, not only from EMC but perhaps also for other myxoid or soft sarcomatous tumours.
CASE REPORT A 50-year-old man presented with an enlarging buttock mass over an 8-month period. An MR examination of the lesion showed a wellcircumscribed, heterogeneous mass involving the right gluteal region and hamstring compartment of the thigh. The mass was of low signal intensity on SE T1-weighted imaging, with heterogeneous appearances on SE T2 weighted imaging with predominant areas of high signal intensity (Fig. 1). The lesion demonstrated heterogeneous enhancement following administration of 40 ml intravenous gadolinium (Magnevist, Berlex Laboratories, NJ, U.S.A.). Percutaneous biopsy of the buttock lesion revealed a highly cellular, myxoid sarcoma composed of small stellate cells resembling immature chondroblasts. Immunohistochemical stains demonstrated an unusual staining pattern positive for keratin, epithelial membrane antigen, actin and desmin, in addition to the typical vimentin and S100 positivity. Electron q 2000 The Royal College of Radiologists