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Giant sacral perineurial cyst a case report
Giant sacral perineurial cyst A case report
Lucia Stella, Arturo
Gambardelia,
and Francesco
Maiuri.
Introduction Summary The perineurial cysts are CSF cysts occurring at the level of the meningeal root sheaths, mainly in the lumbosacral region. They differ from other CSF cysts, because they arise between the perineurium and endoneurium, and their wall typically includes neural elements. Besides, they are often visualized later and incompletely on the myelography, because of their very narrow communication with the subarachnoid space. The perineurial cysts have often been described in autoptic studies and clinical reports’.‘. They are usually small, often multiple, and asymptomatic, and may frequently be observed as an accidental finding on the myelography. They become very rarely large, causing symptoms and signs of nerve root involvement7-24. We report in this paper a rare case of a giant symptomatic sacral perineurial cyst, causing sciatic pain and marked bone erosion of the sacrum. Case report A 44-year-old woman was observed because of a two-month history of lumbar and left sciatic pain. Neurological examination only showed a positive Las?gue sign on the left leg. X-ray of the lumbosacral spine (Fig. 1) re-
Institutes of Neurosurgery
and Radiological
Address for correspondence 5, 80133 Napoli, Italia. Accepted
A rare case of giant sacral perineurial cyst, causing sciatic pain, explored by myelography and computerized tomography, is reported. The cyst, associated with large erosion of the sacrum, was poorly visualized on the myelography, because of its large size, whereas it was better defined on CT scan. Sacral perineurial cysts are usually small and asymptomatic and rarely cause radicular symptoms. The radiological diagnosis and the treatment of these nerve root cysts are briefly discussed. Key words: berineurial cyst, sciatic pain, myefography, computerized tomography.
vealed a large osteolytic area with sclerotic margins in the left half of the sacrum. Computerized tomography (Fig. 2) showed, in the left half of the sacral canal, a large area of CSF density with marked bony erosion, suggesting a CSF cyst. At the water-soluble myelography (Fig. 3) the cyst was found to be very large and incompletely opacified also in the late phase. Because of the late and incomplete opacification, a perineurial cyst was diagnosed. The patient refused operation, because of the triviality of the painful symptomatology. Medical treatment resulted in temporary improvement of the sciatic pain.
Sciences (2ndj, 2nd School of Medicine,
University
of Naples,
ltaiy.
and reprint requests: Francesco Maiuri, lstituto di Neuroc~irurg~a 2” Facoftd di Medicina,
via Punsini
161.89
Clin Neural Neurosurg
1989. Vol. 91-4
343
Fig. 1. Radiogram of the lumbosacral spine in anteroposterior view: large osteolytic area with sclerotic margins in the left half of the sacrum. Fig. 3. Radiculosaccography in anteroposterior view: the CSF cyst demonstrated by CT scan is incompletely opacified even in the late phase.
Fig. 2. Spinal computerized tomography: in the left half of the spinal canal, presence of a large area of CSF density with marked bony erosion (CSF cyst).
Discussion The diagnosis of perineurial cyst in our case has been made on the basis of the very large size of the cyst and its late and incomplete opacification. Because of their very narrow pedicle, the perineurial cysts fill very slowly during myelography; besides, the CSF leaves the cyst with difficulty and therefore it may often reach a very large size by valve mechanism. The neurological troubles due to sacral perineurial cysts include lumbar and sciatic pain, often associated with hypoesthesia and paresthesiae in the region of the involved root. A positive Lasbgue sign, decreased ankle reflex and hypoesthesia of the foot may be observed at neurological examination. This clinical picture is similar to that observed in patients with a lumbar discal hernia; besides, it may sometimes be associated with the cyst. Perineurial cysts slowly and progressively enlarge during life, because of the CSF pressure and a valve mechanism; thus, they produce enlargement of the corresponding intervertebral foramen. Cysts of very large size may rarely cause marked erosion of the sacrum (Fig. 1). With radiculosaccography it is very well possible to visualize the small perineurial cysts; large cysts however are often incompletely visualized, as the contrast medium dilutes in the CSF collection and provides an insufficient opacification of the cyst and a poor definition of its outline. With computerized tomography it is possible to define even very large cysts well, which appear as large low-density areas at the level of the involved root, associated with enlargement of the intervertebral foramen. The lesion becomes highly hyperdense after intrathecal administration of water-soluble contrast24. Thus the CT myelography defines the size of the cyst, its spatial relationship and communication with the subarachnoid space, the displacement of the dural sac. However, these findings are not specific, as other root cysts, extradural or intradural meningeal cysts or diverticula may show similar features’4-26. Magnetic resonance shows the cyst as a mass with low intensity on T,-weighted images and with high intensity on T,-weighted images, similar to the CSF23127.The advantages of magnetic
resonance, including a better resolution of the tissue density, absence of bony interference, and better resolution of reconstructed images in any plane, improve the diagnostic accuracy in the field of the root cysts. Large symptomatic perineurial cysts must be operated on, as they tend to enlarge. Our patient refused temporarily the operation, because of the trivial symptomatology consisting in slight radicular pain; the surgical treatment will be considered in the future, if the periodical clinical follow-up will show the appearance of objective signs of root involvement. The treatment of choice consists in complete removal of the cyst with the involved root; dissection between the cyst and the nervous structures of the root is impossible, because of their close anatomical connection. Alternately, a more limited resection of the cyst wall may be performed, without sacrificing the nerve root and ganglion. The treatment usually results in complete remission or considerably relief of the pain, with regression or improvement of the other disturbances due to root involvement*‘. References VERGA P. Di alcune formazioni pseudocistiche dei net-vi radicolari e dei gangli spinali. Riv Pat Ment 1927; 32~732-829. TARLOV IM. Perineuriaf cysts of the spinal nerve roots. Arch Nemo1 Psychiat 1938; 40:1067-74. TARLOV IM. Cysts (perineurial) of the sacral roots. Another cause (removable) of the sciatic pain. JAMA 1948; 138:740-4. REXED BA, WENNSTROM KG. Arachnoidal proliferation and cyst formation in the spinal nerve root pouches in man. J Neurosurg 19.59; 16:73-84. DICKENMAN RC,CHASONJL. Cysts ofdorsalrootgangha. Report of 29 cases and review of the literature. Arch Path 1964; 77~377-9. LA TORRE E, BINI A, GAGLIARDI FM. Cistispinale extradurale associata a cisti peirneuriah omosegmentarie: profilo clinicoradiologico e considerazioni eziopatogenetiche. Riv Neural 1966; 36:443-54. TARLOV IM. Spinal perineurial and meningeal cysts. J Neural Neurosurg Psychiatry 1970; 33:833-43. WEIFORD EC. Sacral perineurial cyst with case report. Cleveland Clin Quart 1950; 17:106-11. MEREI IT. Mit klinischen Symptomen einhergehende Zysten der Caudawurzeln. Zbl Neurochir 1953; 13:212-g. ~~~07-r KH, RETTER RH, LEIMBACH WH. The role of perineurial sacral cysts in the sciatic and sacrococcygeal syndromes. A review of the literature and report of 9 cases. J Neurosurg 1957; 14:5-21. DAUM s, BILLET R. Deux cas de kystes des racines satrees. Neurochirurgie 1962; 8:111-3. LOMBARDIG,MORELLOG. Congenitafcystsofthe Spinal
345
”
I4
r5 I6
” ‘s
I9 .?a
*i
membranes and roots. Br J Radio1 1963; 36:197-205. Cisti perineurali (Rilievi eziopatogenetici ed illustrazione di un case). Arch Ortop (Milano) 1965; 78:337-44. BERAUD M, MELOCHE BR, LEBLANS P. Les kystes sac& perineuraux de Tarlov. 2 cas. Un Med Can 1967; 96:30-4. RICHTER HS. Sakrale Wurzelzysten als Ursache von Lumbago und Is&as. Acta Neurochir 1967; 16:173. BASAURI L, HUDSON H, BARDALES A. Diverticuliofthe nerve root sheaths. Case report J. Neurosurg 1969; 31:680-2. CLARKE GR. Sciatica caused by sacral nerve-root cysts. Lancet 1970; 2:1135. ROTHMAN RH,JACOBS SR, APPLEMAN w. Spinal extradural cysts. A report of five cases. Clin Orthop 1970; 71:186-92. BRAHAM J. Sacral nerve-root cysts and sciatica. Lancet 1971; 1:45. CARMON A, FEINSOD M. unusual cerebral and spinal symptoms in extradural sacral cysts. Eur Neurol 1971; 5~165-70. BENINI A. Lumbale und sakrale wurseltashendivertikel als ursache Ischiasahulicher Beschwerden. Neurochirurgia 1973; 16:10-8.
”
BIANCHI M.
346
23
24 25
26
”
Z
mubmw
JH, B~bmuI AK, PRAKASH B. Congenital spinal extradural cysts, anterior sacral meningocele and intraspinal root cysts. Different manifestations of the same conditions. Report of seven cases. Acta Neurochir 1973: 29: 177-93. aoozmw~cz w, KAUFMAN B, SPETZLER RF. Diagnosis of sacral perineurial cysts by nuclear magnetic resonance. Surg Neurol 1984; 22:50-2. NI~HIURA I,K~YAMA T, HANDA I.Intrasacral perineurial cysts. Surg Neurol 1985; 23:265-9. YANGWC,RUDANSKYMC,STILLERJ,SHANZERS.VR~Ue Of me&amide CT in the demonstration of spinal arachnoid cysts. Am J Neuroradiol 1983; 4:115-8. SIQUIERA EB, SCHAFFZR L, KRAUSLER W, GAU 'T.CT characteristics of sacral perineurial cysts. Report of two cases. J Neurosurg 1984; 61:5%-8. NABORSMW,PAITTG,BYRDEB~~~~. Update aSSeSSment and current classification of spinal meningeal cysts. J Neurosurg 1988; 68:366-77. WILKINS RH, 0~0~ GL. Spinal extradural cysts. In: Vinken PJ, Rruyn GW (eds): Handbook of Clinical Neurology. vol. 20, 146~54,1976.
Lucia Stella, Arturo
Gambardelia,
and Francesco
Maiuri.
Introduction Summary The perineurial cysts are CSF cysts occurring at the level of the meningeal root sheaths, mainly in the lumbosacral region. They differ from other CSF cysts, because they arise between the perineurium and endoneurium, and their wall typically includes neural elements. Besides, they are often visualized later and incompletely on the myelography, because of their very narrow communication with the subarachnoid space. The perineurial cysts have often been described in autoptic studies and clinical reports’.‘. They are usually small, often multiple, and asymptomatic, and may frequently be observed as an accidental finding on the myelography. They become very rarely large, causing symptoms and signs of nerve root involvement7-24. We report in this paper a rare case of a giant symptomatic sacral perineurial cyst, causing sciatic pain and marked bone erosion of the sacrum. Case report A 44-year-old woman was observed because of a two-month history of lumbar and left sciatic pain. Neurological examination only showed a positive Las?gue sign on the left leg. X-ray of the lumbosacral spine (Fig. 1) re-
Institutes of Neurosurgery
and Radiological
Address for correspondence 5, 80133 Napoli, Italia. Accepted
A rare case of giant sacral perineurial cyst, causing sciatic pain, explored by myelography and computerized tomography, is reported. The cyst, associated with large erosion of the sacrum, was poorly visualized on the myelography, because of its large size, whereas it was better defined on CT scan. Sacral perineurial cysts are usually small and asymptomatic and rarely cause radicular symptoms. The radiological diagnosis and the treatment of these nerve root cysts are briefly discussed. Key words: berineurial cyst, sciatic pain, myefography, computerized tomography.
vealed a large osteolytic area with sclerotic margins in the left half of the sacrum. Computerized tomography (Fig. 2) showed, in the left half of the sacral canal, a large area of CSF density with marked bony erosion, suggesting a CSF cyst. At the water-soluble myelography (Fig. 3) the cyst was found to be very large and incompletely opacified also in the late phase. Because of the late and incomplete opacification, a perineurial cyst was diagnosed. The patient refused operation, because of the triviality of the painful symptomatology. Medical treatment resulted in temporary improvement of the sciatic pain.
Sciences (2ndj, 2nd School of Medicine,
University
of Naples,
ltaiy.
and reprint requests: Francesco Maiuri, lstituto di Neuroc~irurg~a 2” Facoftd di Medicina,
via Punsini
161.89
Clin Neural Neurosurg
1989. Vol. 91-4
343
Fig. 1. Radiogram of the lumbosacral spine in anteroposterior view: large osteolytic area with sclerotic margins in the left half of the sacrum. Fig. 3. Radiculosaccography in anteroposterior view: the CSF cyst demonstrated by CT scan is incompletely opacified even in the late phase.
Fig. 2. Spinal computerized tomography: in the left half of the spinal canal, presence of a large area of CSF density with marked bony erosion (CSF cyst).
Discussion The diagnosis of perineurial cyst in our case has been made on the basis of the very large size of the cyst and its late and incomplete opacification. Because of their very narrow pedicle, the perineurial cysts fill very slowly during myelography; besides, the CSF leaves the cyst with difficulty and therefore it may often reach a very large size by valve mechanism. The neurological troubles due to sacral perineurial cysts include lumbar and sciatic pain, often associated with hypoesthesia and paresthesiae in the region of the involved root. A positive Lasbgue sign, decreased ankle reflex and hypoesthesia of the foot may be observed at neurological examination. This clinical picture is similar to that observed in patients with a lumbar discal hernia; besides, it may sometimes be associated with the cyst. Perineurial cysts slowly and progressively enlarge during life, because of the CSF pressure and a valve mechanism; thus, they produce enlargement of the corresponding intervertebral foramen. Cysts of very large size may rarely cause marked erosion of the sacrum (Fig. 1). With radiculosaccography it is very well possible to visualize the small perineurial cysts; large cysts however are often incompletely visualized, as the contrast medium dilutes in the CSF collection and provides an insufficient opacification of the cyst and a poor definition of its outline. With computerized tomography it is possible to define even very large cysts well, which appear as large low-density areas at the level of the involved root, associated with enlargement of the intervertebral foramen. The lesion becomes highly hyperdense after intrathecal administration of water-soluble contrast24. Thus the CT myelography defines the size of the cyst, its spatial relationship and communication with the subarachnoid space, the displacement of the dural sac. However, these findings are not specific, as other root cysts, extradural or intradural meningeal cysts or diverticula may show similar features’4-26. Magnetic resonance shows the cyst as a mass with low intensity on T,-weighted images and with high intensity on T,-weighted images, similar to the CSF23127.The advantages of magnetic
resonance, including a better resolution of the tissue density, absence of bony interference, and better resolution of reconstructed images in any plane, improve the diagnostic accuracy in the field of the root cysts. Large symptomatic perineurial cysts must be operated on, as they tend to enlarge. Our patient refused temporarily the operation, because of the trivial symptomatology consisting in slight radicular pain; the surgical treatment will be considered in the future, if the periodical clinical follow-up will show the appearance of objective signs of root involvement. The treatment of choice consists in complete removal of the cyst with the involved root; dissection between the cyst and the nervous structures of the root is impossible, because of their close anatomical connection. Alternately, a more limited resection of the cyst wall may be performed, without sacrificing the nerve root and ganglion. The treatment usually results in complete remission or considerably relief of the pain, with regression or improvement of the other disturbances due to root involvement*‘. References VERGA P. Di alcune formazioni pseudocistiche dei net-vi radicolari e dei gangli spinali. Riv Pat Ment 1927; 32~732-829. TARLOV IM. Perineuriaf cysts of the spinal nerve roots. Arch Nemo1 Psychiat 1938; 40:1067-74. TARLOV IM. Cysts (perineurial) of the sacral roots. Another cause (removable) of the sciatic pain. JAMA 1948; 138:740-4. REXED BA, WENNSTROM KG. Arachnoidal proliferation and cyst formation in the spinal nerve root pouches in man. J Neurosurg 19.59; 16:73-84. DICKENMAN RC,CHASONJL. Cysts ofdorsalrootgangha. Report of 29 cases and review of the literature. Arch Path 1964; 77~377-9. LA TORRE E, BINI A, GAGLIARDI FM. Cistispinale extradurale associata a cisti peirneuriah omosegmentarie: profilo clinicoradiologico e considerazioni eziopatogenetiche. Riv Neural 1966; 36:443-54. TARLOV IM. Spinal perineurial and meningeal cysts. J Neural Neurosurg Psychiatry 1970; 33:833-43. WEIFORD EC. Sacral perineurial cyst with case report. Cleveland Clin Quart 1950; 17:106-11. MEREI IT. Mit klinischen Symptomen einhergehende Zysten der Caudawurzeln. Zbl Neurochir 1953; 13:212-g. ~~~07-r KH, RETTER RH, LEIMBACH WH. The role of perineurial sacral cysts in the sciatic and sacrococcygeal syndromes. A review of the literature and report of 9 cases. J Neurosurg 1957; 14:5-21. DAUM s, BILLET R. Deux cas de kystes des racines satrees. Neurochirurgie 1962; 8:111-3. LOMBARDIG,MORELLOG. Congenitafcystsofthe Spinal
345
”
I4
r5 I6
” ‘s
I9 .?a
*i
membranes and roots. Br J Radio1 1963; 36:197-205. Cisti perineurali (Rilievi eziopatogenetici ed illustrazione di un case). Arch Ortop (Milano) 1965; 78:337-44. BERAUD M, MELOCHE BR, LEBLANS P. Les kystes sac& perineuraux de Tarlov. 2 cas. Un Med Can 1967; 96:30-4. RICHTER HS. Sakrale Wurzelzysten als Ursache von Lumbago und Is&as. Acta Neurochir 1967; 16:173. BASAURI L, HUDSON H, BARDALES A. Diverticuliofthe nerve root sheaths. Case report J. Neurosurg 1969; 31:680-2. CLARKE GR. Sciatica caused by sacral nerve-root cysts. Lancet 1970; 2:1135. ROTHMAN RH,JACOBS SR, APPLEMAN w. Spinal extradural cysts. A report of five cases. Clin Orthop 1970; 71:186-92. BRAHAM J. Sacral nerve-root cysts and sciatica. Lancet 1971; 1:45. CARMON A, FEINSOD M. unusual cerebral and spinal symptoms in extradural sacral cysts. Eur Neurol 1971; 5~165-70. BENINI A. Lumbale und sakrale wurseltashendivertikel als ursache Ischiasahulicher Beschwerden. Neurochirurgia 1973; 16:10-8.
”
BIANCHI M.
346
23
24 25
26
”
Z
mubmw
JH, B~bmuI AK, PRAKASH B. Congenital spinal extradural cysts, anterior sacral meningocele and intraspinal root cysts. Different manifestations of the same conditions. Report of seven cases. Acta Neurochir 1973: 29: 177-93. aoozmw~cz w, KAUFMAN B, SPETZLER RF. Diagnosis of sacral perineurial cysts by nuclear magnetic resonance. Surg Neurol 1984; 22:50-2. NI~HIURA I,K~YAMA T, HANDA I.Intrasacral perineurial cysts. Surg Neurol 1985; 23:265-9. YANGWC,RUDANSKYMC,STILLERJ,SHANZERS.VR~Ue Of me&amide CT in the demonstration of spinal arachnoid cysts. Am J Neuroradiol 1983; 4:115-8. SIQUIERA EB, SCHAFFZR L, KRAUSLER W, GAU 'T.CT characteristics of sacral perineurial cysts. Report of two cases. J Neurosurg 1984; 61:5%-8. NABORSMW,PAITTG,BYRDEB~~~~. Update aSSeSSment and current classification of spinal meningeal cysts. J Neurosurg 1988; 68:366-77. WILKINS RH, 0~0~ GL. Spinal extradural cysts. In: Vinken PJ, Rruyn GW (eds): Handbook of Clinical Neurology. vol. 20, 146~54,1976.