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British Journal of Neurosurgery Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/ibjn20
Calcifying pseudoneoplasm of the foramen magnum—Case report and review of the literature a
b
a
b
Karol Wiśniewski , Karolina Janczar , Krzysztof Tybor , Wielisław Papierz & Dariusz J. a
Jaskólski a
Department of Neurosurgery and Neurooncology, Medical University of Lodz, Barlicki University Hospital, Lodz, Poland b
Department of Pathomorphology, Medical University of Lodz, Lodz, Poland Published online: 30 Jun 2015.
To cite this article: Karol Wiśniewski, Karolina Janczar, Krzysztof Tybor, Wielisław Papierz & Dariusz J. Jaskólski (2015): Calcifying pseudoneoplasm of the foramen magnum—Case report and review of the literature, British Journal of Neurosurgery To link to this article: http://dx.doi.org/10.3109/02688697.2015.1039491
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
British Journal of Neurosurgery, 2015; Early Online: 1–3 © 2015 The Neurosurgical Foundation ISSN: 0268-8697 print / ISSN 1360-046X online DOI: 10.3109/02688697.2015.1039491
SHORT REPORT
Calcifying pseudoneoplasm of the foramen magnum—Case report and review of the literature Karol Wiśniewski1, Karolina Janczar2, Krzysztof Tybor1, Wielisław Papierz2 & Dariusz J. Jaskólski1 1Department of Neurosurgery and Neurooncology, Medical University of Lodz, Barlicki University Hospital, Lodz, Poland and
Downloaded by [University of Otago] at 14:47 11 July 2015
2Department of Pathomorphology, Medical University of Lodz, Lodz, Poland
department. Special emphasis is put on the neuroradiological, histopathological, and intraoperative features of the lesion.
Abstract We present a case of a 29-year-old male with a calcifying pseudoneoplasm of the neuraxis (CAPNON) located in the region of the foramen magnum, treated successfully by complete resection. After a 2-year follow-up the patient remains recurrence free. Clinical and histopathological characterization of CAPNON is provided with special emphasis on the intraoperative and neuroradiological features of the lesion.
Case description The patient, currently a male aged 29 years, had been referred to the outpatients neurology service due to severe headaches and impeded rotation of the head to the left in 2010 at the age of 24. Neurological examination was otherwise unremarkable. Computerized tomography (CT) performed at the time revealed a strongly calcified lesion of about 2 cm in diameter on the right side of the cervical spine, close to the foramen magnum. Subsequently, magnetic resonance imaging (MRI) demonstrated a demarcated, irregular focal lesion, 20 ⫻ 15 ⫻ 13 mm, located in the right part of the foramen magnum. The lesion was hypointense in T1-weighted image and iso-/hypointense in T2-weighted sequences, and was strong, heterogeneous in gadolinium contrast enhancement (Fig. 1A, B and C). At that time, the patient was operated on in another neurosurgical center and the lesion was partially resected via a far lateral approach (as indicated by the diagnostic imaging) (Fig. 1D). The histological examination of the material revealed features of an inflammatory process confined mainly to the bone, with focal necrosis and nonspecific granulation. Special stainings excluded tuberculosis and fungosis, and the diagnosis of a pseudo-inflammatory tumor was established. The patient was followed up by a neurosurgeon on an outpatient basis. In 2012, the patient was admitted to our department due to severe headache and limited head rotation to the left. MRI showed a single, well-demarcated, 21 ⫻ 17 ⫻ 15 mm lesion next to the foramen magnum on the right side. The lesion was hypointensive in T1- and T2-weighted sequences and
Keywords: calcifying pseudoneoplasm of the neuraxis; CAPNON as benign brain lesion; CAPNON clinical manifestation; CAPNON MRI
Introduction A calcifying pseudoneoplasm of the neuraxis (CAPNON) is an uncommon lesion localized more frequently in the extremities than within the central nervous system (CNS). Little is known about the etiology and the natural history of a CAPNON as the vast majority of literature publications so far are single case reports. Since its first description by Rhodos and Davis in 1978, only 45 cases located in the CNS have been reported in literature. A CAPNON is regarded as a benign, reactive process with morbidities related to its local effects. The clinical symptoms are due to mass effect and perifocal edema rather than intrinsic features of the lesion.1 As a CAPNON is a rare entity characterized by an excellent prognosis, the optimal time for surgical intervention is not well established. It is suggested that increasing size of the lesion is associated with surgical complications. Here, we present a patient with a CAPNON in the region of the foramen magnum who was operated on at our
Correspondence: Karol Wiśniewski, Department of Neurosurgery and Neurooncology, Kopcińskiego 22, 90-153 Lodz, Poland. Tel: ⫹(48) 42-677-67-70. Fax: ⫹(48) 42-677-67-81. E-mail: [email protected] (Received for publication 4 February 2015; accepted 30 March 2015)
1
Downloaded by [University of Otago] at 14:47 11 July 2015
2
K. Wiśniewski et al.
Fig. 1. (A) MRI before the first surgery shows lesion located at the level of foramen magnum. The lesion is well demarcated. T1-weighted image of the lesion is hypointense. (B) T1-weighted image (after administration of gadolinium) where the lesion has two hyper- and isointense components. (C) T2-weighted image where the lesion is heterogeneous and consists of two iso- and hypointense parts. (D) CT scans performed 1 month after the first operation (far lateral approach was performed) shows that the lesion was comparable to that before the surgery.
showed a peripheral contrast enhancement (Fig. 2A). The lesion was surgically removed fully via a far lateral approach. Intraoperatively it was found to be well demarcated, firm, and homogenous (Fig. 2B). Histopathological examination revealed multiple round-to-oval microcalcifications surrounded by spindles and epithelioid cells (Fig. 2C). In some areas, the cells were arranged in a palisade manner. Some of these cells revealed immunoexpression of epithelial membrane antigen (EMA) (Fig. 2D), while the reactions with antibody against S-100 protein, smooth muscle actin, and CD-68 were negative. The lesion contained some thin-walled blood vessels, and several bone trabeculae were also seen. Mitotic figures were absent. Proliferative index, calculated on the basis of Ki-67 immunohistochemical reaction, was 0%. On the basis of the microscopic picture and results of immunohistochemical reaction diagnosis, a diagnosis of CAPNON was established.
Discussion In the presented case, magnetic resonance examination was strongly suggestive toward a CAPNON. While the MRI might be indicative of a CAPNON, microscopic examination is mandatory for diagnosis. The histopathological examination of a CAPNON reveals areas of extensive calcifications. Within the lesion, variable amounts of fibrous stroma with areas of extensive calcification and nodules of chondromyxoid matrix surrounded by cells with morphology spectrum from spindle to epithelioid are observed. Areas of osseous
metaplasia, foreign body giant cells, and psammoma bodies may be identified. The presence of histopathological features other than the calcifications is highly variable in each lesion. Mitotic activity is virtually absent. CAPNON is a rare lesion with male predominance (1.92:1),1 the incidence of which is inestimable. According to the literature there is no clear age predominance; CAPNONs were described both in children as well as adults. The age of patients ranged from 6 to 83 years.2 Among 45 cases of CNS CAPNONs described in literature, 33 were located intracranially and 12 in the spinal canal, mainly in the epidural space. The etiology of the lesion is unknown; however, it is suggested that it derives from arachnoid cells, fibroblasts, or other cell types of mesenchymal phenotype. The clinical presentation of a CAPNON depends on the anatomical location and the size of the lesion. Symptoms are related to local compression. The most common symptoms in patients with intracranial localization are headaches and seizures. In cases of spinal CAPNON, the clinical presentation is most commonly neck or lumbar pain, depending on the lesion location. In this particular case, headaches and movement restriction of the patient’s head were the only symptoms noticeable at presentation. The neuroradiological features of intracranial CAPNON are calcifications in CT and T1- as well as T2-hypointensity with peripheral gadolinium enhancement, usually without features of edema in MRI. These should therefore be considered in the differential diagnosis of intracranial tumors
Downloaded by [University of Otago] at 14:47 11 July 2015
CAPNON
3
Fig. 2. (A) MRI before the second surgery. T2-weighted image where the lesion is hypointense. (B) Intraoperatively the tumor was well demarcated, firm, and homogenous. (C) Cellular, calcified areas surrounded by spindle to epithelioid cells. Hematoxylin and eosin staining. Original magnification 200⫻. (D) EMA expression in some of the spindle and epithelioid cells. Peroxidase immunohistochemistry. Original magnification 200⫻.
presenting with radiographic characteristics consistent with a fibro-osseous lesion. CAPNON may at times be suspected intraoperatively based on the macroscopical examination. In this case, the lesion was well demarcated, very firm, homogenous, and grayish yellow in color. It is necessary to stress that an accurate final diagnosis should be based on histopathological examination. The prognosis in cases of a CAPNON is excellent. Total surgical resection (or endoscopic resection—in select patients with sinonasal extension) of the lesion is curable, and so far no relapses were reported even after suboptimal removal, though deaths following the resection of skullbased CAPNONs were reported.3
Conclusions A CAPNON is a benign lesion, reactive in nature, of a yet unknown origin. Clinical treatment should be considered in case of a strongly calcified lesion visible on CT, while a T1- as well as a T2-hypointensive signal is encountered
during MRI, usually without features of edema in magnetic resonance. An intraoperatively well-demarcated, firm, and homogenous lesion should raise suspicion of a CAPNON. Only a histopathological examination may provide a correct diagnosis, preventing the patient from having to undergo aggressive adjuvant therapy. Declaration of interest: The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.
References 1. Stienen MN, Abdulazim A , Gautschi OP, et al. Calcifying pseudoneoplasms of the neuraxis (CAPNON): Clinical features and therapeutic options. Acta Neurochir (Wien) 2013;155:9–17. 2. Hodges TR, Karikari IO, Nimjee SM, et al. Calcifying pseudoneoplasm of the cerebellopontine angle: Case report. Neurosurgery 2011;69:onsE117–E120. 3. Fletcher AM, Greenlee JJ, Chang KE, et al. Endoscopic resection of calcifying pseudoneoplasm of the neuraxis (CAPNON) of the anterior skull base with sinonasal extension. J Clin Neurosci 2012;19:1048–9.
British Journal of Neurosurgery Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/ibjn20
Calcifying pseudoneoplasm of the foramen magnum—Case report and review of the literature a
b
a
b
Karol Wiśniewski , Karolina Janczar , Krzysztof Tybor , Wielisław Papierz & Dariusz J. a
Jaskólski a
Department of Neurosurgery and Neurooncology, Medical University of Lodz, Barlicki University Hospital, Lodz, Poland b
Department of Pathomorphology, Medical University of Lodz, Lodz, Poland Published online: 30 Jun 2015.
To cite this article: Karol Wiśniewski, Karolina Janczar, Krzysztof Tybor, Wielisław Papierz & Dariusz J. Jaskólski (2015): Calcifying pseudoneoplasm of the foramen magnum—Case report and review of the literature, British Journal of Neurosurgery To link to this article: http://dx.doi.org/10.3109/02688697.2015.1039491
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
British Journal of Neurosurgery, 2015; Early Online: 1–3 © 2015 The Neurosurgical Foundation ISSN: 0268-8697 print / ISSN 1360-046X online DOI: 10.3109/02688697.2015.1039491
SHORT REPORT
Calcifying pseudoneoplasm of the foramen magnum—Case report and review of the literature Karol Wiśniewski1, Karolina Janczar2, Krzysztof Tybor1, Wielisław Papierz2 & Dariusz J. Jaskólski1 1Department of Neurosurgery and Neurooncology, Medical University of Lodz, Barlicki University Hospital, Lodz, Poland and
Downloaded by [University of Otago] at 14:47 11 July 2015
2Department of Pathomorphology, Medical University of Lodz, Lodz, Poland
department. Special emphasis is put on the neuroradiological, histopathological, and intraoperative features of the lesion.
Abstract We present a case of a 29-year-old male with a calcifying pseudoneoplasm of the neuraxis (CAPNON) located in the region of the foramen magnum, treated successfully by complete resection. After a 2-year follow-up the patient remains recurrence free. Clinical and histopathological characterization of CAPNON is provided with special emphasis on the intraoperative and neuroradiological features of the lesion.
Case description The patient, currently a male aged 29 years, had been referred to the outpatients neurology service due to severe headaches and impeded rotation of the head to the left in 2010 at the age of 24. Neurological examination was otherwise unremarkable. Computerized tomography (CT) performed at the time revealed a strongly calcified lesion of about 2 cm in diameter on the right side of the cervical spine, close to the foramen magnum. Subsequently, magnetic resonance imaging (MRI) demonstrated a demarcated, irregular focal lesion, 20 ⫻ 15 ⫻ 13 mm, located in the right part of the foramen magnum. The lesion was hypointense in T1-weighted image and iso-/hypointense in T2-weighted sequences, and was strong, heterogeneous in gadolinium contrast enhancement (Fig. 1A, B and C). At that time, the patient was operated on in another neurosurgical center and the lesion was partially resected via a far lateral approach (as indicated by the diagnostic imaging) (Fig. 1D). The histological examination of the material revealed features of an inflammatory process confined mainly to the bone, with focal necrosis and nonspecific granulation. Special stainings excluded tuberculosis and fungosis, and the diagnosis of a pseudo-inflammatory tumor was established. The patient was followed up by a neurosurgeon on an outpatient basis. In 2012, the patient was admitted to our department due to severe headache and limited head rotation to the left. MRI showed a single, well-demarcated, 21 ⫻ 17 ⫻ 15 mm lesion next to the foramen magnum on the right side. The lesion was hypointensive in T1- and T2-weighted sequences and
Keywords: calcifying pseudoneoplasm of the neuraxis; CAPNON as benign brain lesion; CAPNON clinical manifestation; CAPNON MRI
Introduction A calcifying pseudoneoplasm of the neuraxis (CAPNON) is an uncommon lesion localized more frequently in the extremities than within the central nervous system (CNS). Little is known about the etiology and the natural history of a CAPNON as the vast majority of literature publications so far are single case reports. Since its first description by Rhodos and Davis in 1978, only 45 cases located in the CNS have been reported in literature. A CAPNON is regarded as a benign, reactive process with morbidities related to its local effects. The clinical symptoms are due to mass effect and perifocal edema rather than intrinsic features of the lesion.1 As a CAPNON is a rare entity characterized by an excellent prognosis, the optimal time for surgical intervention is not well established. It is suggested that increasing size of the lesion is associated with surgical complications. Here, we present a patient with a CAPNON in the region of the foramen magnum who was operated on at our
Correspondence: Karol Wiśniewski, Department of Neurosurgery and Neurooncology, Kopcińskiego 22, 90-153 Lodz, Poland. Tel: ⫹(48) 42-677-67-70. Fax: ⫹(48) 42-677-67-81. E-mail: [email protected] (Received for publication 4 February 2015; accepted 30 March 2015)
1
Downloaded by [University of Otago] at 14:47 11 July 2015
2
K. Wiśniewski et al.
Fig. 1. (A) MRI before the first surgery shows lesion located at the level of foramen magnum. The lesion is well demarcated. T1-weighted image of the lesion is hypointense. (B) T1-weighted image (after administration of gadolinium) where the lesion has two hyper- and isointense components. (C) T2-weighted image where the lesion is heterogeneous and consists of two iso- and hypointense parts. (D) CT scans performed 1 month after the first operation (far lateral approach was performed) shows that the lesion was comparable to that before the surgery.
showed a peripheral contrast enhancement (Fig. 2A). The lesion was surgically removed fully via a far lateral approach. Intraoperatively it was found to be well demarcated, firm, and homogenous (Fig. 2B). Histopathological examination revealed multiple round-to-oval microcalcifications surrounded by spindles and epithelioid cells (Fig. 2C). In some areas, the cells were arranged in a palisade manner. Some of these cells revealed immunoexpression of epithelial membrane antigen (EMA) (Fig. 2D), while the reactions with antibody against S-100 protein, smooth muscle actin, and CD-68 were negative. The lesion contained some thin-walled blood vessels, and several bone trabeculae were also seen. Mitotic figures were absent. Proliferative index, calculated on the basis of Ki-67 immunohistochemical reaction, was 0%. On the basis of the microscopic picture and results of immunohistochemical reaction diagnosis, a diagnosis of CAPNON was established.
Discussion In the presented case, magnetic resonance examination was strongly suggestive toward a CAPNON. While the MRI might be indicative of a CAPNON, microscopic examination is mandatory for diagnosis. The histopathological examination of a CAPNON reveals areas of extensive calcifications. Within the lesion, variable amounts of fibrous stroma with areas of extensive calcification and nodules of chondromyxoid matrix surrounded by cells with morphology spectrum from spindle to epithelioid are observed. Areas of osseous
metaplasia, foreign body giant cells, and psammoma bodies may be identified. The presence of histopathological features other than the calcifications is highly variable in each lesion. Mitotic activity is virtually absent. CAPNON is a rare lesion with male predominance (1.92:1),1 the incidence of which is inestimable. According to the literature there is no clear age predominance; CAPNONs were described both in children as well as adults. The age of patients ranged from 6 to 83 years.2 Among 45 cases of CNS CAPNONs described in literature, 33 were located intracranially and 12 in the spinal canal, mainly in the epidural space. The etiology of the lesion is unknown; however, it is suggested that it derives from arachnoid cells, fibroblasts, or other cell types of mesenchymal phenotype. The clinical presentation of a CAPNON depends on the anatomical location and the size of the lesion. Symptoms are related to local compression. The most common symptoms in patients with intracranial localization are headaches and seizures. In cases of spinal CAPNON, the clinical presentation is most commonly neck or lumbar pain, depending on the lesion location. In this particular case, headaches and movement restriction of the patient’s head were the only symptoms noticeable at presentation. The neuroradiological features of intracranial CAPNON are calcifications in CT and T1- as well as T2-hypointensity with peripheral gadolinium enhancement, usually without features of edema in MRI. These should therefore be considered in the differential diagnosis of intracranial tumors
Downloaded by [University of Otago] at 14:47 11 July 2015
CAPNON
3
Fig. 2. (A) MRI before the second surgery. T2-weighted image where the lesion is hypointense. (B) Intraoperatively the tumor was well demarcated, firm, and homogenous. (C) Cellular, calcified areas surrounded by spindle to epithelioid cells. Hematoxylin and eosin staining. Original magnification 200⫻. (D) EMA expression in some of the spindle and epithelioid cells. Peroxidase immunohistochemistry. Original magnification 200⫻.
presenting with radiographic characteristics consistent with a fibro-osseous lesion. CAPNON may at times be suspected intraoperatively based on the macroscopical examination. In this case, the lesion was well demarcated, very firm, homogenous, and grayish yellow in color. It is necessary to stress that an accurate final diagnosis should be based on histopathological examination. The prognosis in cases of a CAPNON is excellent. Total surgical resection (or endoscopic resection—in select patients with sinonasal extension) of the lesion is curable, and so far no relapses were reported even after suboptimal removal, though deaths following the resection of skullbased CAPNONs were reported.3
Conclusions A CAPNON is a benign lesion, reactive in nature, of a yet unknown origin. Clinical treatment should be considered in case of a strongly calcified lesion visible on CT, while a T1- as well as a T2-hypointensive signal is encountered
during MRI, usually without features of edema in magnetic resonance. An intraoperatively well-demarcated, firm, and homogenous lesion should raise suspicion of a CAPNON. Only a histopathological examination may provide a correct diagnosis, preventing the patient from having to undergo aggressive adjuvant therapy. Declaration of interest: The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.
References 1. Stienen MN, Abdulazim A , Gautschi OP, et al. Calcifying pseudoneoplasms of the neuraxis (CAPNON): Clinical features and therapeutic options. Acta Neurochir (Wien) 2013;155:9–17. 2. Hodges TR, Karikari IO, Nimjee SM, et al. Calcifying pseudoneoplasm of the cerebellopontine angle: Case report. Neurosurgery 2011;69:onsE117–E120. 3. Fletcher AM, Greenlee JJ, Chang KE, et al. Endoscopic resection of calcifying pseudoneoplasm of the neuraxis (CAPNON) of the anterior skull base with sinonasal extension. J Clin Neurosci 2012;19:1048–9.
