Novel Insights from Clinical Practice Pediatr Neurosurg 2014–15;50:53–55 DOI: 10.1159/000369936
Received: September 29, 2014 Accepted: November 9, 2014 Published online: January 21, 2015
Occipital Post-Traumatic Intradiploic Arachnoid Cyst Converted to Pseudomeningocele after Re-Trauma: A Rare Complication of Rare Pathology Manish Jaiswal Ashok Gandhi Achal Sharma R.S. Mittal Department of Neurosurgery, SMS Medical College and Hospital, JLN Marg, Jaipur, India
Established Facts • Post-traumatic intradiploic arachnoid cyst (PTIAC), a variant of growing skull fracture, is an extremely rare entity. • It is usually asymptomatic, presenting with only a hard swelling or a mild headache.
Novel Insights • PTIAC may rupture with trivial trauma and convert into pseudomeningocele. • En masse removal with dural-defect repair is the treatment of choice in this situation.
Abstract Background: Growing skull fracture (GSF)/pseudomeningocele is a rare complication of head injury in children. Posttraumatic intradiploic arachnoid cyst (PTIAC) is a variant but it is extremely rare. PTIACs are usually asymptomatic or with mild symptoms like headache. The rupture of PTIAC due to re-trauma leading to pseudomeningocele formation has not been seen or reported before. Patient and Method: We present a case of occipital PTIAC where pseudomeningocele developed after re-trauma, and discuss the pathogenesis and management. Result: En masse removal of the ruptured
© 2015 S. Karger AG, Basel 1016–2291/15/0501–0053$39.50/0 E-Mail [email protected] www.karger.com/pne
PTIAC was performed along with dural-defect repair. The post-operative recovery was good. Conclusion: PTIAC is an extremely rare occurrence as a variant of GSF. It is usually asymptomatic, but it may rupture with trivial trauma due to a thinned-out outer table and then converts into pseudomengocele. En masse excision with dural-defect repair gives good results in cases of ruptured PTIAC due to re-trauma. © 2015 S. Karger AG, Basel
Introduction
Growing skull fracture (GSF)/pseudomeningocele is a rare osteolytic lesion involving the cranium. It mainly occurs in childhood and contributes to an incidence of 0.05–1.6% of paediatric skull fractures [1, 2]. Rarely, an Manish Jaiswal A 33/48 A 2 Omkareshwar, Varanasi 221001 Uttar Pradesh (India) E-Mail manishmlnmc @ gmail.com
Downloaded by: University of Pittsburgh 198.143.32.65 - 8/14/2015 5:24:55 AM
Key Words Post-traumatic intradiploic arachnoid cyst · Growing skull fracture · Pseudomeningocele
Color version available online
Fig. 1. Occipital region swellings of a ruptured PTIAC.
Fig. 2. Computed tomography scan of the head showing a PTIAC
with fracture of both the inner and outer tables due to re-trauma.
Color version available online
intradiploic cyst is formed as a variant of GSF. The occipital bone is an uncommon location for GSF/peudomeningocele [3–5]. Post-traumatic intradiploic arachnoid cyst (PTIAC), a variant of GSF, is a rare entity and only a few case reports on this topic are available in the literature. PTIAC is usually asymptomatic. Rupture or fracture of PTIAC has not been reported or seen before. We report on a case of PTIAC in a child who presented with fluctuating swelling in the occipital region due to retrauma, which led to the conversion of PTIAC into pseudomeningocele.
Case Report
54
Pediatr Neurosurg 2014–15;50:53–55 DOI: 10.1159/000369936
Fig. 3. En masse-removed specimen of a PTIAC showing a fractured outer table.
cerebrospinal fluid (CSF) was flowing into the cyst. The fractured occipital bone was removed en masse (fig. 3) and the dural defect was closed. The post-operative period was uneventful and patient’s neurological status had improved at the time of discharge.
Discussion
GSF is commonly seen in the parietal bone as opposed to in the temporal or occipital bone, probably because of the protection afforded by the overlying musculature [6]. PTIAC is a rare complication of skull fracture. It has been Jaiswal/Gandhi/Sharma/Mittal
Downloaded by: University of Pittsburgh 198.143.32.65 - 8/14/2015 5:24:55 AM
A 4-year-old child presented with altered consciousness and occipital region swelling. There was a recent history of falling after slipping in the bathroom 1 month previously. Since then, the shape of his head had been abnormal, with 2 cystic swellings in the occipital region. On examination, a cross-fluctuation was present between the 2 swellings (fig. 1). Neurologically, the patient was drowsy, with the presence of bilateral cerebellar signs. His grandfather informed us that he had had a previous head injury about 2 years before. At that time, he had been unconscious for 2 days and was treated at a local hospital. Since then, the occipital region of his head had been gradually increasing in size and was hard in consistency. The cystic swellings had appeared recently, after the second episode of head injury. He also had a history of repeated falls while walking in the last few months. A computed tomography scan showed a widening of the intradiploic space of the occipital bone, with multiple fractures of both the tables. The fourth ventricle was compressed (fig. 2). In surgery, the diploic space of the occipital bone was found to be widened and lined with arachnoid. The inner table of occipital bone was defective with an underlying dural defect through which
reported after head injury in the first decade of childhood [5]. It is rarely seen in the occipital bone; we could find only a few case reports in the available literature [1–10]. The pathogenesis of PTIAC appears to be due to a linear fracture in the inner table of the bone with an intact outer table, and a dural tear through which the arachnoid prolapses through the fracture line into the intradiploic space. The basic difference between a GSF and a PTIAC concerns the fracture of the outer and inner tables of the skull bone. In GSF, both the tables fracture along with a dural tear, but in PTIAC, there is fracture only of the inner table along with dural tear. The usual thickness of the inner table of the skull is 0.5 mm and that of the outer table is 1.5 mm. In the squamous part of the occipital bone, the diploe is less developed. This might also favour the development of the cyst due to less resistance being offered by the inner table and diploe. The outer table is not breached and remains intact since it is thicker and buttressed with the sub-occipital muscles. The constant pulsations of the CSF further propagate the arachnoid and CSF into the fracture line, leading to expansion of the intradiploic space [10]. In most cases, the occipital intradiploic arachnoid cyst is not seen spreading anteriorly towards the foramen magnum as the occipital bone develops from two distinct parts: the upper squamous part develops as a membranous bone and the lower basal part as a cartilaginous bone which is thicker at the occipital condyles [11]. An intradiploic cyst differs from a GSF in terms of the absence of seizures or hemiparesis and it is usually asymptomatic. On MRI, evidence of a porencephalic cyst, encephalitis or any other brain injury is commonly seen in cases of GSF, and these are caused by the prolapse of
brain matter along with the arachnoid through the fracture line. However, in PTIAC, these are usually not seen. In our case, the patient had a definite history of trauma 2 years previously. Since then, his head had been growing disproportionally in the occipital region and he had developed cerebellar signs in the form of an ataxic gait in the last few months. Following the second injury, there were multiple fractures in the thinned-out outer table, leading to collection of CSF under the scalp, making for a rare type of presentation. The surgical management of PTIAC is dural-defect repair and reconstruction of the inner-table defect with the use of outer-table bone. However, in this particular case, there were also multiple fractures of the outer table due to re-trauma, so we did not have the option of using the outer table as reconstruction material. We therefore planned to excise the PTIAC en masse and perform dural repair. This resulted in a good outcome.
Conclusion
PTIAC is an extremely rare occurrence as a variant of GSF. It is usually asymptomatic, but it may rupture with trivial trauma due to a thinned-out outer table and converts into pseudomengocele. En masse excision with dural-defect repair gives good results in cases of ruptured PTIAC due to re-trauma.
Disclosure Statement No disclosures.
References
Ruptured PTIAC
5 Martinez–Lage JF, Martinez PM, Domingo R, Poza M: Post-traumatic arachnoid cyst of the posterior fossa. Childs Nerv Syst 1997; 13: 293–296. 6 Tizzard S, Gleave J, Antoun W, Macfarlane R: Occipito clival intradiploic meningocele following skull fracture in infancy. Br J Neurosurg 2001;15:188–190. 7 Hamamcioglu MK, Hicdonmez T, Kilincer C, Cobanoglu S: Large intradiploic growing skull fracture of the posterior fossa. Pediatr Radiol 2006;36:1. 8 Seo BR, Lee JK, Jeong IH, Moon SJ, Joo SP, Kim TS, Kim JH, Kim SH: Posttraumatic intradiploic leptomeningeal cyst of the posterior fossa in an adult. J Clin Neurosci 2009; 16: 1367–1369.
9 Turgut M, Ozcan OE, Karaman CZ: Posttraumatic intraosseous pseudomeningocele of the occipital bone. Australas Radiol 1997; 42:262–263. 10 Taveras JM, Rosenhoff J: Leptomeningeal cysts of the brain following trauma with erosion of the skull. A study of seven cases treated by surgery. J Neurosurg 1953; 233– 241. 11 Wickenhauser J, Hochberg O: Development anomalies of the occiput. Pediatr Radiol 1974; 2:217–220.
Pediatr Neurosurg 2014–15;50:53–55 DOI: 10.1159/000369936
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1 Açikgöz B, Tekkök IH: Post-traumatic intradiploic leptomeningeal fistula and cyst. J Clin Neurosci 2002;9:468–473. 2 Ersahin Y, Gulmen V, Palali I, Mutluer Sl: Growing skull fractures (craniocerebral erosion). Neurosurg Rev 2000;23:139–144. 3 Gorgulu A, Albayrak BS: Giant intradiploic leptomeningeal cyst of the posterior fossa. Acta Neurochir (Wien) 2006;148:923–924. 4 Lunardi P, Missori P, Artico M, Fortuna A: Posttraumatic intradiploic leptomeningeal cyst in an adult: case report. Surg Neurol 1991; 35:475–477.
Received: September 29, 2014 Accepted: November 9, 2014 Published online: January 21, 2015
Occipital Post-Traumatic Intradiploic Arachnoid Cyst Converted to Pseudomeningocele after Re-Trauma: A Rare Complication of Rare Pathology Manish Jaiswal Ashok Gandhi Achal Sharma R.S. Mittal Department of Neurosurgery, SMS Medical College and Hospital, JLN Marg, Jaipur, India
Established Facts • Post-traumatic intradiploic arachnoid cyst (PTIAC), a variant of growing skull fracture, is an extremely rare entity. • It is usually asymptomatic, presenting with only a hard swelling or a mild headache.
Novel Insights • PTIAC may rupture with trivial trauma and convert into pseudomeningocele. • En masse removal with dural-defect repair is the treatment of choice in this situation.
Abstract Background: Growing skull fracture (GSF)/pseudomeningocele is a rare complication of head injury in children. Posttraumatic intradiploic arachnoid cyst (PTIAC) is a variant but it is extremely rare. PTIACs are usually asymptomatic or with mild symptoms like headache. The rupture of PTIAC due to re-trauma leading to pseudomeningocele formation has not been seen or reported before. Patient and Method: We present a case of occipital PTIAC where pseudomeningocele developed after re-trauma, and discuss the pathogenesis and management. Result: En masse removal of the ruptured
© 2015 S. Karger AG, Basel 1016–2291/15/0501–0053$39.50/0 E-Mail [email protected] www.karger.com/pne
PTIAC was performed along with dural-defect repair. The post-operative recovery was good. Conclusion: PTIAC is an extremely rare occurrence as a variant of GSF. It is usually asymptomatic, but it may rupture with trivial trauma due to a thinned-out outer table and then converts into pseudomengocele. En masse excision with dural-defect repair gives good results in cases of ruptured PTIAC due to re-trauma. © 2015 S. Karger AG, Basel
Introduction
Growing skull fracture (GSF)/pseudomeningocele is a rare osteolytic lesion involving the cranium. It mainly occurs in childhood and contributes to an incidence of 0.05–1.6% of paediatric skull fractures [1, 2]. Rarely, an Manish Jaiswal A 33/48 A 2 Omkareshwar, Varanasi 221001 Uttar Pradesh (India) E-Mail manishmlnmc @ gmail.com
Downloaded by: University of Pittsburgh 198.143.32.65 - 8/14/2015 5:24:55 AM
Key Words Post-traumatic intradiploic arachnoid cyst · Growing skull fracture · Pseudomeningocele
Color version available online
Fig. 1. Occipital region swellings of a ruptured PTIAC.
Fig. 2. Computed tomography scan of the head showing a PTIAC
with fracture of both the inner and outer tables due to re-trauma.
Color version available online
intradiploic cyst is formed as a variant of GSF. The occipital bone is an uncommon location for GSF/peudomeningocele [3–5]. Post-traumatic intradiploic arachnoid cyst (PTIAC), a variant of GSF, is a rare entity and only a few case reports on this topic are available in the literature. PTIAC is usually asymptomatic. Rupture or fracture of PTIAC has not been reported or seen before. We report on a case of PTIAC in a child who presented with fluctuating swelling in the occipital region due to retrauma, which led to the conversion of PTIAC into pseudomeningocele.
Case Report
54
Pediatr Neurosurg 2014–15;50:53–55 DOI: 10.1159/000369936
Fig. 3. En masse-removed specimen of a PTIAC showing a fractured outer table.
cerebrospinal fluid (CSF) was flowing into the cyst. The fractured occipital bone was removed en masse (fig. 3) and the dural defect was closed. The post-operative period was uneventful and patient’s neurological status had improved at the time of discharge.
Discussion
GSF is commonly seen in the parietal bone as opposed to in the temporal or occipital bone, probably because of the protection afforded by the overlying musculature [6]. PTIAC is a rare complication of skull fracture. It has been Jaiswal/Gandhi/Sharma/Mittal
Downloaded by: University of Pittsburgh 198.143.32.65 - 8/14/2015 5:24:55 AM
A 4-year-old child presented with altered consciousness and occipital region swelling. There was a recent history of falling after slipping in the bathroom 1 month previously. Since then, the shape of his head had been abnormal, with 2 cystic swellings in the occipital region. On examination, a cross-fluctuation was present between the 2 swellings (fig. 1). Neurologically, the patient was drowsy, with the presence of bilateral cerebellar signs. His grandfather informed us that he had had a previous head injury about 2 years before. At that time, he had been unconscious for 2 days and was treated at a local hospital. Since then, the occipital region of his head had been gradually increasing in size and was hard in consistency. The cystic swellings had appeared recently, after the second episode of head injury. He also had a history of repeated falls while walking in the last few months. A computed tomography scan showed a widening of the intradiploic space of the occipital bone, with multiple fractures of both the tables. The fourth ventricle was compressed (fig. 2). In surgery, the diploic space of the occipital bone was found to be widened and lined with arachnoid. The inner table of occipital bone was defective with an underlying dural defect through which
reported after head injury in the first decade of childhood [5]. It is rarely seen in the occipital bone; we could find only a few case reports in the available literature [1–10]. The pathogenesis of PTIAC appears to be due to a linear fracture in the inner table of the bone with an intact outer table, and a dural tear through which the arachnoid prolapses through the fracture line into the intradiploic space. The basic difference between a GSF and a PTIAC concerns the fracture of the outer and inner tables of the skull bone. In GSF, both the tables fracture along with a dural tear, but in PTIAC, there is fracture only of the inner table along with dural tear. The usual thickness of the inner table of the skull is 0.5 mm and that of the outer table is 1.5 mm. In the squamous part of the occipital bone, the diploe is less developed. This might also favour the development of the cyst due to less resistance being offered by the inner table and diploe. The outer table is not breached and remains intact since it is thicker and buttressed with the sub-occipital muscles. The constant pulsations of the CSF further propagate the arachnoid and CSF into the fracture line, leading to expansion of the intradiploic space [10]. In most cases, the occipital intradiploic arachnoid cyst is not seen spreading anteriorly towards the foramen magnum as the occipital bone develops from two distinct parts: the upper squamous part develops as a membranous bone and the lower basal part as a cartilaginous bone which is thicker at the occipital condyles [11]. An intradiploic cyst differs from a GSF in terms of the absence of seizures or hemiparesis and it is usually asymptomatic. On MRI, evidence of a porencephalic cyst, encephalitis or any other brain injury is commonly seen in cases of GSF, and these are caused by the prolapse of
brain matter along with the arachnoid through the fracture line. However, in PTIAC, these are usually not seen. In our case, the patient had a definite history of trauma 2 years previously. Since then, his head had been growing disproportionally in the occipital region and he had developed cerebellar signs in the form of an ataxic gait in the last few months. Following the second injury, there were multiple fractures in the thinned-out outer table, leading to collection of CSF under the scalp, making for a rare type of presentation. The surgical management of PTIAC is dural-defect repair and reconstruction of the inner-table defect with the use of outer-table bone. However, in this particular case, there were also multiple fractures of the outer table due to re-trauma, so we did not have the option of using the outer table as reconstruction material. We therefore planned to excise the PTIAC en masse and perform dural repair. This resulted in a good outcome.
Conclusion
PTIAC is an extremely rare occurrence as a variant of GSF. It is usually asymptomatic, but it may rupture with trivial trauma due to a thinned-out outer table and converts into pseudomengocele. En masse excision with dural-defect repair gives good results in cases of ruptured PTIAC due to re-trauma.
Disclosure Statement No disclosures.
References
Ruptured PTIAC
5 Martinez–Lage JF, Martinez PM, Domingo R, Poza M: Post-traumatic arachnoid cyst of the posterior fossa. Childs Nerv Syst 1997; 13: 293–296. 6 Tizzard S, Gleave J, Antoun W, Macfarlane R: Occipito clival intradiploic meningocele following skull fracture in infancy. Br J Neurosurg 2001;15:188–190. 7 Hamamcioglu MK, Hicdonmez T, Kilincer C, Cobanoglu S: Large intradiploic growing skull fracture of the posterior fossa. Pediatr Radiol 2006;36:1. 8 Seo BR, Lee JK, Jeong IH, Moon SJ, Joo SP, Kim TS, Kim JH, Kim SH: Posttraumatic intradiploic leptomeningeal cyst of the posterior fossa in an adult. J Clin Neurosci 2009; 16: 1367–1369.
9 Turgut M, Ozcan OE, Karaman CZ: Posttraumatic intraosseous pseudomeningocele of the occipital bone. Australas Radiol 1997; 42:262–263. 10 Taveras JM, Rosenhoff J: Leptomeningeal cysts of the brain following trauma with erosion of the skull. A study of seven cases treated by surgery. J Neurosurg 1953; 233– 241. 11 Wickenhauser J, Hochberg O: Development anomalies of the occiput. Pediatr Radiol 1974; 2:217–220.
Pediatr Neurosurg 2014–15;50:53–55 DOI: 10.1159/000369936
55
Downloaded by: University of Pittsburgh 198.143.32.65 - 8/14/2015 5:24:55 AM
1 Açikgöz B, Tekkök IH: Post-traumatic intradiploic leptomeningeal fistula and cyst. J Clin Neurosci 2002;9:468–473. 2 Ersahin Y, Gulmen V, Palali I, Mutluer Sl: Growing skull fractures (craniocerebral erosion). Neurosurg Rev 2000;23:139–144. 3 Gorgulu A, Albayrak BS: Giant intradiploic leptomeningeal cyst of the posterior fossa. Acta Neurochir (Wien) 2006;148:923–924. 4 Lunardi P, Missori P, Artico M, Fortuna A: Posttraumatic intradiploic leptomeningeal cyst in an adult: case report. Surg Neurol 1991; 35:475–477.
