Journal of Clinical Neuroscience xxx (2014) xxx–xxx
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Neuroradiology Report
Spontaneous regression of an epidermoid cyst of the cavernous sinus Vijay Yanamadala a,b, Ning Lin b,c, Brian P. Walcott a,b,⇑, Lissa C. Baird d, Edward R. Smith b,c a
Department of Neurosurgery, Massachusetts General Hospital, 55 Fruit Street, White Building Room 502, Boston, MA 02114, USA Harvard Medical School, Boston, MA, USA c Department of Neurosurgery, Children’s Hospital Boston, Boston, MA, USA d Department of Neurosurgery, Oregon Health & Science University, Portland, OR, USA b
a r t i c l e
i n f o
Article history: Received 3 October 2013 Accepted 13 November 2013 Available online xxxx Keywords: Cavernous sinus Epidermoid cyst Neuroradiology Spontaneous regression Surgery
a b s t r a c t Epidermoid cysts are rare lesions in the pediatric population. The natural history of epidermoids is usually that of slow growth, although rupture and cases of malignant transformation have been reported. Spontaneous regression of an intracranial epidermoid cyst has not previously been described to our knowledge. We present a 3-year-old boy who presented with severe vertigo. MRI was performed which revealed a 2 cm non-enhancing lesion in the right cavernous sinus. The lesion was T1-hypoinsense, T2-hyperintense, and with evidence of restricted diffusion, consistent with an epidermoid cyst. The patient was followed with annual MRI studies over the next 3 years, demonstrating progressive reduction in the size of the lesion over time, with complete resolution after 3 years. The child’s symptoms also resolved during this period. Long-term follow-up imaging at 5 years showed no evident lesion. To our knowledge, this is the first report documenting spontaneous regression of an intracranial epidermoid cyst. While isolated, this finding demonstrates the potential for involution of epidermoids and lends support to the clinical practice of careful observation of these lesions, especially when located in areas associated with high potential surgical morbidity. Importantly, the novelty of this observation suggests a need for further study to better elucidate the underlying mechanism of this regression. Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction Epidermoid cysts are generally benign cysts representing approximately 1% of all intracranial tumors [1]. They are thought to arise from rests of ectodermal remnants that fail to undergo regression after the completion of neural embryogenesis at the fifth week of gestation [2]. The most common intracranial location for epidermoid cysts is the cerebellopontine angle [3], although they have also been reported in the cavernous sinus [4,5], Meckel’s cave [6], middle ear [7], sphenoid sinus [8], calvarial bones [9], as well as various extracranial sites. The MRI characteristics of epidermoid cysts, including T1-hypointensity and T2-hyperintensity with areas of restricted diffusion, make them distinct from other intracranial tumors and cysts [10]. The natural history of epidermoid cysts is usually that of slow growth [11], with a median age at presentation of 40 years, although rupture [12,13] and malignant transformation [14] have been reported. Here we present a rare case of an epidermoid cyst of the cavernous sinus in a pediatric patient, which spontaneously resolved on serial imaging without
⇑ Corresponding author. Tel.: +1 617 726 2000; fax: +1 617 643 4113. E-mail address: [email protected] (B.P. Walcott).
intervention over a 3 year period. To our knowledge, this is the first report of spontaneous resolution of an intracranial epidermoid cyst in the literature. 2. Clinical case A 3-year-old boy presented with recurrent vertigo. He had no other neurological symptoms and his neurological examination was intact. His past medical history was notable only for an episode of immune thrombocytopenic purpura at age 2 requiring hospitalization, and mild asthma. The patient had no family history of intracranial tumors or cysts, neurofibromatosis, or other phakomatoses. Initial MRI revealed a 2.0 1.0 cm mass within the right cavernous sinus that was hypointense on T1-weighted imaging, hyperintense on T2-weighted imaging, did not enhance with gadolinium contrast, and demonstrated areas of restricted diffusion (Fig. 1). These MRI findings were highly suggestive of an epidermoid cyst. Given the absence of other neurological symptoms and the potential morbidity associated with surgery in this location, the decision was made not to intervene, and the patient was followed with annual MRI studies. Subsequent imaging demonstrated progressive decrease in the size of the lesion over time, with complete resolution 3 years after
http://dx.doi.org/10.1016/j.jocn.2013.11.054 0967-5868/Ó 2014 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Yanamadala V et al. Spontaneous regression of an epidermoid cyst of the cavernous sinus. J Clin Neurosci (2014), http:// dx.doi.org/10.1016/j.jocn.2013.11.054
2
V. Yanamadala et al. / Journal of Clinical Neuroscience xxx (2014) xxx–xxx
Fig. 1. Axial MRI of the brain at presentation. A mass lesion was identified at the right cavernous sinus, which was bright on T2-weighted imaging (A) and diffusion weighted imaging (B), dark on T1-weighted imaging (C, D), and showed no enhancement with contrast (D).
Fig. 2. Axial T2-weighted (A) diffusion weighted (B), T1-weighted (C), and T1-weighted contrast enhanced (D) MRI of the brain 3 years after presentation. The mass lesion at the right cavernous sinus was no longer visible.
its discovery (Fig. 2). The child’s symptoms also resolved during this period. Latest follow-up imaging at 5 years following initial diagnosis demonstrated an area of scar tissue or mineralization adjacent to the right cavernous sinus, with no evidence of residual or recurrent epidermoid cyst (Fig. 3).
3. Discussion Intracranial epidermoid cysts are rare and account for approximately 1% of all brain tumors [1]. Because they have a distinct bright diffusion signal compared to other cystic lesions, such as arachnoid cysts, epidermoids can usually be diagnosed with a high degree of certainty on MRI images [15]. The natural history of epidermoid cysts is derived from adult series and is generally considered benign with low growth rate, although cyst rupture can sometimes occur, resulting in aseptic meningitis, ventriculitis, granulomatous arachnoiditis, and even aqueductal stenosis [13,16]. In extremely rare occasions, epidermoid cysts can undergo malignant transformation and degenerate into squamous cell carcinoma with invasion of brain parenchyma [14,17]. The natural history of epidermoids in children is unclear. Few cases of epidermoid cysts in the pediatric population have been reported in the literature [18,19]. Caldarelli et al. reviewed a series of 19 children who were surgically treated for intracranial inclusion cysts, three of whom had epidermoids [18]. The authors found that gross total resection was achieved in two children, and the third child underwent subtotal resection initially and required additional surgery subsequently for recurrence. Ahmed et al. reported a larger series of seven patients with surgically treated intracranial epidermoid cysts [19]. The authors showed that complete resection could be performed in two patients, and that one subtotally resected lesion recurred and required additional
Fig. 3. Axial T2-weighted (A) and T1-weighted (B) MRI of the brain 5 years after presentation at the latest follow-up showing no evidence of residual or recurrent epidermoid cyst.
operation. These results were largely consistent with those reported in adult patients, for whom total resection was achievable in 50–80% of cases [20]. We present an epidermoid cyst of the cavernous sinus in a child that spontaneously regressed over a 3 year period without intervention. To our knowledge, this is the first report documenting spontaneous resolution of an intracranial epidermoid cyst. While unique, this finding demonstrates the potential for involution of epidermoids and lends support to the clinical practice of careful observation of these lesions, especially when located in areas associated with high potential surgical morbidity and when the patient is mildly symptomatic or asymptomatic. The novelty of this observation also suggests a need for further study to better elucidate the underlying mechanism of this cyst regression. In considering possible mechanisms, it is worthwhile
Please cite this article in press as: Yanamadala V et al. Spontaneous regression of an epidermoid cyst of the cavernous sinus. J Clin Neurosci (2014), http:// dx.doi.org/10.1016/j.jocn.2013.11.054
V. Yanamadala et al. / Journal of Clinical Neuroscience xxx (2014) xxx–xxx
to consider the embryological origin of epidermoid cysts. Epidermoid cysts originate from rests of embryonic epidermal tissue that abnormally proliferate, with cyst formation occurring as central cells undergo necrosis and slough [21]. Given the embryological origin of epidermoid tumors, this spontaneous regression may be the result of delayed apoptosis, cyst resorption, or even immunological control. Alternatively, cyst rupture with subsequent resorption of the contents is also possible, although the highly inflammatory nature of the cholesterol-laden fluid contained within the epidermoid make this less likely without signs of meningismus. Distinguishing between these various possibilities may become possible as more cases of this nature are described in the future. In conclusion, spontaneous regression may be the natural history of a proportion of epidermoid cysts. Watchful waiting may be a reasonable treatment option in the case of asymptomatic or mildly symptomatic epidermoids, particularly in the pediatric population and especially when located close to vital structures or in difficult to access intracranial locations. Conflicts of Interest/Disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. References [1] Guidetti B, Gagliardi FM. Epidermoid and dermoid cysts. Clinical evaluation and late surgical results. J Neurosurg 1977;47:12–8. [2] Netsky MG. Epidermoid tumors. Review of the literature. Surg Neurol 1988;29:477–83. [3] Obrador S, Lopez-Zafra JJ. Clinical features of the epidermoids of the basal cisterns of the brain. J Neurol Neurosurg Psychiatry 1969;32:450–4. [4] Gharabaghi A, Koerbel A, Samii A, et al. Epidermoid cysts of the cavernous sinus. Surg Neurol 2005;64:428–33 [discussion 433].
3
[5] Tatagiba M, Iaconetta G, Samii M. Epidermoid cyst of the cavernous sinus: clinical features, pathogenesis and treatment. Br J Neurosurg 2000;14:571–5. [6] Ohta H, Ottomo M, Nakamura T, et al. A case of epidermoid tumor inside the Meckel’s cave. No Shinkei Geka 1997;25:943–7. [7] Michaels L. Origin of congenital cholesteatoma from a normally occurring epidermoid rest in the developing middle ear. Int J Pediatr Otorhinolaryngol 1988;15:51–65. [8] Ohta S, Nishizawa S, Ryu H, et al. Epidermoid tumor in the sphenoid sinus–case report. Neurol Med Chir (Tokyo) 1997;37:350–3. [9] Holthusen W, Lassrich MA, Steiner C. Epidermoids and dermoids of the calvarian bones in early childhood: their behaviour in the growing skull. Pediatr Radiol 1983;13:189–94. [10] Steffey DJ, De Filipp GJ, Spera T, et al. MR imaging of primary epidermoid tumors. J Comput Assist Tomogr 1988;12:438–40. [11] Alvord Jr EC. Growth rates of epidermoid tumors. Ann Neurol 1977;2:367–70. [12] Wang J, Chang M, Luo S. Spontaneously ruptured pineal epidermoid cyst associated with a thalamic germinoma. Neurosurgery 1989;24:933–6. [13] Schwartz JF, Balentine JD. Recurrent meningitis due to an intracranial epidermoid. Neurology 1978;28:124–9. [14] Link MJ, Cohen PL, Breneman JC, et al. Malignant squamous degeneration of a cerebellopontine angle epidermoid tumor. Case report. J Neurosurg 2002;97:1237–43. [15] Vion-Dury J, Vincentelli F, Jiddane M, et al. MR imaging of epidermoid cysts. Neuroradiology 1987;29:333–8. [16] Abramson RC, Morawetz RB, Schlitt M. Multiple complications from an intracranial epidermoid cyst: case report and literature review. Neurosurgery 1989;24:574–8. [17] Agarwal S, Rishi A, Suri V, et al. Primary intracranial squamous cell carcinoma arising in an epidermoid cyst–a case report and review of literature. Clin Neurol Neurosurg 2007;109:888–91. [18] Caldarelli M, Massimi L, Kondageski C, et al. Intracranial midline dermoid and epidermoid cysts in children. J Neurosurg 2004;100:473–80. [19] Ahmed I, Auguste KI, Vachhrajani S, et al. Neurosurgical management of intracranial epidermoid tumors in children. Clinical article. J Neurosurg Pediatr 2009;4:91–6. [20] Samii M, Tatagiba M, Piquer J, et al. Surgical treatment of epidermoid cysts of the cerebellopontine angle. J Neurosurg 1996;84:14–9. [21] Persaud R, Liang J, Upile T, et al. Epidermoid formation: the potential precursor of congenital cholesteatomas. Am J Otolaryngol 2006;27:71–2 [author reply 72].
Please cite this article in press as: Yanamadala V et al. Spontaneous regression of an epidermoid cyst of the cavernous sinus. J Clin Neurosci (2014), http:// dx.doi.org/10.1016/j.jocn.2013.11.054
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Neuroradiology Report
Spontaneous regression of an epidermoid cyst of the cavernous sinus Vijay Yanamadala a,b, Ning Lin b,c, Brian P. Walcott a,b,⇑, Lissa C. Baird d, Edward R. Smith b,c a
Department of Neurosurgery, Massachusetts General Hospital, 55 Fruit Street, White Building Room 502, Boston, MA 02114, USA Harvard Medical School, Boston, MA, USA c Department of Neurosurgery, Children’s Hospital Boston, Boston, MA, USA d Department of Neurosurgery, Oregon Health & Science University, Portland, OR, USA b
a r t i c l e
i n f o
Article history: Received 3 October 2013 Accepted 13 November 2013 Available online xxxx Keywords: Cavernous sinus Epidermoid cyst Neuroradiology Spontaneous regression Surgery
a b s t r a c t Epidermoid cysts are rare lesions in the pediatric population. The natural history of epidermoids is usually that of slow growth, although rupture and cases of malignant transformation have been reported. Spontaneous regression of an intracranial epidermoid cyst has not previously been described to our knowledge. We present a 3-year-old boy who presented with severe vertigo. MRI was performed which revealed a 2 cm non-enhancing lesion in the right cavernous sinus. The lesion was T1-hypoinsense, T2-hyperintense, and with evidence of restricted diffusion, consistent with an epidermoid cyst. The patient was followed with annual MRI studies over the next 3 years, demonstrating progressive reduction in the size of the lesion over time, with complete resolution after 3 years. The child’s symptoms also resolved during this period. Long-term follow-up imaging at 5 years showed no evident lesion. To our knowledge, this is the first report documenting spontaneous regression of an intracranial epidermoid cyst. While isolated, this finding demonstrates the potential for involution of epidermoids and lends support to the clinical practice of careful observation of these lesions, especially when located in areas associated with high potential surgical morbidity. Importantly, the novelty of this observation suggests a need for further study to better elucidate the underlying mechanism of this regression. Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction Epidermoid cysts are generally benign cysts representing approximately 1% of all intracranial tumors [1]. They are thought to arise from rests of ectodermal remnants that fail to undergo regression after the completion of neural embryogenesis at the fifth week of gestation [2]. The most common intracranial location for epidermoid cysts is the cerebellopontine angle [3], although they have also been reported in the cavernous sinus [4,5], Meckel’s cave [6], middle ear [7], sphenoid sinus [8], calvarial bones [9], as well as various extracranial sites. The MRI characteristics of epidermoid cysts, including T1-hypointensity and T2-hyperintensity with areas of restricted diffusion, make them distinct from other intracranial tumors and cysts [10]. The natural history of epidermoid cysts is usually that of slow growth [11], with a median age at presentation of 40 years, although rupture [12,13] and malignant transformation [14] have been reported. Here we present a rare case of an epidermoid cyst of the cavernous sinus in a pediatric patient, which spontaneously resolved on serial imaging without
⇑ Corresponding author. Tel.: +1 617 726 2000; fax: +1 617 643 4113. E-mail address: [email protected] (B.P. Walcott).
intervention over a 3 year period. To our knowledge, this is the first report of spontaneous resolution of an intracranial epidermoid cyst in the literature. 2. Clinical case A 3-year-old boy presented with recurrent vertigo. He had no other neurological symptoms and his neurological examination was intact. His past medical history was notable only for an episode of immune thrombocytopenic purpura at age 2 requiring hospitalization, and mild asthma. The patient had no family history of intracranial tumors or cysts, neurofibromatosis, or other phakomatoses. Initial MRI revealed a 2.0 1.0 cm mass within the right cavernous sinus that was hypointense on T1-weighted imaging, hyperintense on T2-weighted imaging, did not enhance with gadolinium contrast, and demonstrated areas of restricted diffusion (Fig. 1). These MRI findings were highly suggestive of an epidermoid cyst. Given the absence of other neurological symptoms and the potential morbidity associated with surgery in this location, the decision was made not to intervene, and the patient was followed with annual MRI studies. Subsequent imaging demonstrated progressive decrease in the size of the lesion over time, with complete resolution 3 years after
http://dx.doi.org/10.1016/j.jocn.2013.11.054 0967-5868/Ó 2014 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Yanamadala V et al. Spontaneous regression of an epidermoid cyst of the cavernous sinus. J Clin Neurosci (2014), http:// dx.doi.org/10.1016/j.jocn.2013.11.054
2
V. Yanamadala et al. / Journal of Clinical Neuroscience xxx (2014) xxx–xxx
Fig. 1. Axial MRI of the brain at presentation. A mass lesion was identified at the right cavernous sinus, which was bright on T2-weighted imaging (A) and diffusion weighted imaging (B), dark on T1-weighted imaging (C, D), and showed no enhancement with contrast (D).
Fig. 2. Axial T2-weighted (A) diffusion weighted (B), T1-weighted (C), and T1-weighted contrast enhanced (D) MRI of the brain 3 years after presentation. The mass lesion at the right cavernous sinus was no longer visible.
its discovery (Fig. 2). The child’s symptoms also resolved during this period. Latest follow-up imaging at 5 years following initial diagnosis demonstrated an area of scar tissue or mineralization adjacent to the right cavernous sinus, with no evidence of residual or recurrent epidermoid cyst (Fig. 3).
3. Discussion Intracranial epidermoid cysts are rare and account for approximately 1% of all brain tumors [1]. Because they have a distinct bright diffusion signal compared to other cystic lesions, such as arachnoid cysts, epidermoids can usually be diagnosed with a high degree of certainty on MRI images [15]. The natural history of epidermoid cysts is derived from adult series and is generally considered benign with low growth rate, although cyst rupture can sometimes occur, resulting in aseptic meningitis, ventriculitis, granulomatous arachnoiditis, and even aqueductal stenosis [13,16]. In extremely rare occasions, epidermoid cysts can undergo malignant transformation and degenerate into squamous cell carcinoma with invasion of brain parenchyma [14,17]. The natural history of epidermoids in children is unclear. Few cases of epidermoid cysts in the pediatric population have been reported in the literature [18,19]. Caldarelli et al. reviewed a series of 19 children who were surgically treated for intracranial inclusion cysts, three of whom had epidermoids [18]. The authors found that gross total resection was achieved in two children, and the third child underwent subtotal resection initially and required additional surgery subsequently for recurrence. Ahmed et al. reported a larger series of seven patients with surgically treated intracranial epidermoid cysts [19]. The authors showed that complete resection could be performed in two patients, and that one subtotally resected lesion recurred and required additional
Fig. 3. Axial T2-weighted (A) and T1-weighted (B) MRI of the brain 5 years after presentation at the latest follow-up showing no evidence of residual or recurrent epidermoid cyst.
operation. These results were largely consistent with those reported in adult patients, for whom total resection was achievable in 50–80% of cases [20]. We present an epidermoid cyst of the cavernous sinus in a child that spontaneously regressed over a 3 year period without intervention. To our knowledge, this is the first report documenting spontaneous resolution of an intracranial epidermoid cyst. While unique, this finding demonstrates the potential for involution of epidermoids and lends support to the clinical practice of careful observation of these lesions, especially when located in areas associated with high potential surgical morbidity and when the patient is mildly symptomatic or asymptomatic. The novelty of this observation also suggests a need for further study to better elucidate the underlying mechanism of this cyst regression. In considering possible mechanisms, it is worthwhile
Please cite this article in press as: Yanamadala V et al. Spontaneous regression of an epidermoid cyst of the cavernous sinus. J Clin Neurosci (2014), http:// dx.doi.org/10.1016/j.jocn.2013.11.054
V. Yanamadala et al. / Journal of Clinical Neuroscience xxx (2014) xxx–xxx
to consider the embryological origin of epidermoid cysts. Epidermoid cysts originate from rests of embryonic epidermal tissue that abnormally proliferate, with cyst formation occurring as central cells undergo necrosis and slough [21]. Given the embryological origin of epidermoid tumors, this spontaneous regression may be the result of delayed apoptosis, cyst resorption, or even immunological control. Alternatively, cyst rupture with subsequent resorption of the contents is also possible, although the highly inflammatory nature of the cholesterol-laden fluid contained within the epidermoid make this less likely without signs of meningismus. Distinguishing between these various possibilities may become possible as more cases of this nature are described in the future. In conclusion, spontaneous regression may be the natural history of a proportion of epidermoid cysts. Watchful waiting may be a reasonable treatment option in the case of asymptomatic or mildly symptomatic epidermoids, particularly in the pediatric population and especially when located close to vital structures or in difficult to access intracranial locations. Conflicts of Interest/Disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. References [1] Guidetti B, Gagliardi FM. Epidermoid and dermoid cysts. Clinical evaluation and late surgical results. J Neurosurg 1977;47:12–8. [2] Netsky MG. Epidermoid tumors. Review of the literature. Surg Neurol 1988;29:477–83. [3] Obrador S, Lopez-Zafra JJ. Clinical features of the epidermoids of the basal cisterns of the brain. J Neurol Neurosurg Psychiatry 1969;32:450–4. [4] Gharabaghi A, Koerbel A, Samii A, et al. Epidermoid cysts of the cavernous sinus. Surg Neurol 2005;64:428–33 [discussion 433].
3
[5] Tatagiba M, Iaconetta G, Samii M. Epidermoid cyst of the cavernous sinus: clinical features, pathogenesis and treatment. Br J Neurosurg 2000;14:571–5. [6] Ohta H, Ottomo M, Nakamura T, et al. A case of epidermoid tumor inside the Meckel’s cave. No Shinkei Geka 1997;25:943–7. [7] Michaels L. Origin of congenital cholesteatoma from a normally occurring epidermoid rest in the developing middle ear. Int J Pediatr Otorhinolaryngol 1988;15:51–65. [8] Ohta S, Nishizawa S, Ryu H, et al. Epidermoid tumor in the sphenoid sinus–case report. Neurol Med Chir (Tokyo) 1997;37:350–3. [9] Holthusen W, Lassrich MA, Steiner C. Epidermoids and dermoids of the calvarian bones in early childhood: their behaviour in the growing skull. Pediatr Radiol 1983;13:189–94. [10] Steffey DJ, De Filipp GJ, Spera T, et al. MR imaging of primary epidermoid tumors. J Comput Assist Tomogr 1988;12:438–40. [11] Alvord Jr EC. Growth rates of epidermoid tumors. Ann Neurol 1977;2:367–70. [12] Wang J, Chang M, Luo S. Spontaneously ruptured pineal epidermoid cyst associated with a thalamic germinoma. Neurosurgery 1989;24:933–6. [13] Schwartz JF, Balentine JD. Recurrent meningitis due to an intracranial epidermoid. Neurology 1978;28:124–9. [14] Link MJ, Cohen PL, Breneman JC, et al. Malignant squamous degeneration of a cerebellopontine angle epidermoid tumor. Case report. J Neurosurg 2002;97:1237–43. [15] Vion-Dury J, Vincentelli F, Jiddane M, et al. MR imaging of epidermoid cysts. Neuroradiology 1987;29:333–8. [16] Abramson RC, Morawetz RB, Schlitt M. Multiple complications from an intracranial epidermoid cyst: case report and literature review. Neurosurgery 1989;24:574–8. [17] Agarwal S, Rishi A, Suri V, et al. Primary intracranial squamous cell carcinoma arising in an epidermoid cyst–a case report and review of literature. Clin Neurol Neurosurg 2007;109:888–91. [18] Caldarelli M, Massimi L, Kondageski C, et al. Intracranial midline dermoid and epidermoid cysts in children. J Neurosurg 2004;100:473–80. [19] Ahmed I, Auguste KI, Vachhrajani S, et al. Neurosurgical management of intracranial epidermoid tumors in children. Clinical article. J Neurosurg Pediatr 2009;4:91–6. [20] Samii M, Tatagiba M, Piquer J, et al. Surgical treatment of epidermoid cysts of the cerebellopontine angle. J Neurosurg 1996;84:14–9. [21] Persaud R, Liang J, Upile T, et al. Epidermoid formation: the potential precursor of congenital cholesteatomas. Am J Otolaryngol 2006;27:71–2 [author reply 72].
Please cite this article in press as: Yanamadala V et al. Spontaneous regression of an epidermoid cyst of the cavernous sinus. J Clin Neurosci (2014), http:// dx.doi.org/10.1016/j.jocn.2013.11.054
