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Mature teratoma arising from the middle cranial fossa
RADIOLOGIC-PATHOLOGIC CORRELATION
Mature Teratoma Arising From the Middle Cranial Fossa Rahul S. Phadke, MD, Asha S. Shenoy, MD, Anjana Hosangadi, MD, and Trimurti D. Nadkarni, MS A 25-year-old man presented with a sudden spurt in size of a bony swelling around the external ear, which was present since birth. This was associated with a painful swelling of the right half of the face and pain, redness, and decreased vision in the right eye. Neurologic examination showed decreased visual acuity in the right eye and paresis of the fifth, seventh, and eighth cranial nerves. Neuroimaging showed an extra-axial, partly cystic tumor of mixed density, located entirely within the middle cranial fossa scalloping the temporal bone and extending into the right infratemporal fossa and the right middle ear and impinging on the ipsilateral cavernous sinus. The right temporal lobe was elevated and compressed. Histopathologic examination confirmed a mature teratoma. Ann Diagn Pathol 8: 28-31, 2004. © 2004 Elsevier Inc. All rights reserved. Index Words: Mature teratoma, middle cranial fossa, extra axial, cavernous sinus
A
25-year-old man presented with a history of a bony swelling around the right external ear and drooping of the right eyelid since birth. Recently, he had noticed an increase in the size of the swelling over the past few days. This was coupled with swelling of the right half of the face and pain, redness, and decreased vision in the right eye. Neurologic examination showed decreased visual acuity in the right eye and a corneal opacity. Fundoscopy showed a markedly congested optic disc with absent venous pulsations. There was paresis of the fifth, seventh, and eighth cranial nerves. The lower cranial nerves were normal. There was no motor deficit or any cerebellar signs. Computerized tomography of the brain showed an extra-axial, well-defined, low-attenuated, hypodense, lobulated, and partly cystic tumor within the middle cranial fossa, with a central calcified component and peripheral fat density (Fig 1). The tumor produced scalloping of the petrous and squamous portions of the temporal bone. Anteriorly, it extended up to the cavernous sinus and the foramen lacerum. The right temporal lobe was
From the Departments of Pathology and Neurosurgery, Seth G.S. Medical College and K.E.M. Hospital, Mumbai. Address reprint requests to Rahul S. Phadke, MD, Department of Histopathology, St Thomas’ Hospital, 2nd Floor, North Wing, Lambeth Palace Road, London SE1 7EH UK. © 2004 Elsevier Inc. All rights reserved. 1092-9134/04/0801-0005$30.00/0 doi:10.1016/j.anndiagpath.2003.11.003
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elevated and compressed. Magnetic resonance imaging of the brain showed a large, partly cystic tumor of mixed density, with areas of calcification. The right internal carotid artery and the right middle cerebral artery were stretched out with compression of the ipsilateral cavernous sinus (Fig 2). The tumor extended into the right infratemporal fossa and the right middle ear. There was no extension into the brain parenchyma. A right temporo-basal craniectomy with subtotal excision of a partly cystic tumor was performed. The postoperative course was uneventful. There was persistent fifth, seventh, and eighth nerve paresis. The lower cranial nerves were normal. Subsequent follow-up data were unavailable. The tumor was received as multiple soft tissue bits aggregating five cm. Most bits were grayish and soft. Some bits had a gritty consistency. A few membranous bits were noted. Some tissue bits had a hemorrhagic appearance. Histopathologic examination of multiple tissue sections showed most tissue bits to be composed of mature glial tissue, with widespread calcification within (Fig 3). Some of the larger calcific deposits resembled calcospherules. The deposits were mainly perivascular in location. Some tissue bits were lined by flattened to cuboidal epithelial cells, some of which contained a melanin-like pigment. Glandular spaces lined by similar epithelium were embedded within the glial tissue. Also seen were tissue bits lined by tall columnar gastric-type epithelium beneath which were mature adipose tissue (Fig 4), salivary type sero-
Annals of Diagnostic Pathology, Vol 8, No 1 (February), 2004: pp 28-31
Teratoma Arising From the Middle Cranial Fossa
Figure 1. Computed tomography shows an extra-axial tumor of mixed density, with central calcification (arrow), arising within the right middle cranial fossa.
mucinous acini (Fig 5), glandular spaces lined by flattened to cuboidal epithelium, and mature glial tissue were closely juxtaposed in an organoid fashion. There were no immature elements or any malignant component. Fibrocollagenous bits, possibly representing dura, were seen. These histopathologic features suggested a mature teratoma.
29
poral bone and extending into the middle ear, the initial radiologic diagnoses considered were aneurysmal bone cyst, giant cell tumor, or epidermoid cyst. The clinical impression was that of a choleasteatoma. Histopathologic examination ruled out these possibilities. The main differential diagnoses considered were glial heterotopia/encephalocoele versus teratoma. Pathologically, there are no significant differences between neuroglial heterotopia and encephalocoele in the middle ear region. Both are characterized by varying proportions of neurons and glia, with associated chronic inflammation and gliosis.10 Depending on the presence or absence of a central nervous system connection, either heterotopia or encephalocoele may be the appropriate terms for these lesions. The absence of any parenchymal connection ruled out an encephalocoele in the present case. Most middle ear heterotopias/encephalocoeles are characterized by presence of flattened to cuboidal epithelium and glandular elements most likely representing entrapped tympanic cavity or eustachian tube epithelium and need to be differentiated from teratomatous elements.10 The presence of tumor bits composed of gastric-type epithelium, adipose tis-
Discussion Teratomas may be classified as mature or immature depending on the degree of differentiation of their component tissues. Mature teratomas are identified by the presence of fully differentiated elements derived from all three germinal layers. Intracranial teratomas are rare, comprising 0.5% of all intracranial neoplasms.1 Most examples occur in a midline location in the pineal region followed by the suprasellar/hypothalamic region.1,2 Non-midline cases are rare, and occasional cases are reported to occur in the basal ganglia, lateral ventricle, fourth ventricle, Sylvian fissure, cavernous sinus, sella, and the temporal bone.3-9 Such rare cases can present considerable diagnostic challenge, and a thorough reappraisal of the clinical presentation, radiologic features, and histopathology is essential to arrive at an accurate diagnosis. In the present case, with an extra-axial, partly cystic middle cranial fossa lesion partly eroding the tem-
Figure 2. Magnetic resonance imaging of the brain shows an extra-axial tumor of mixed density stretching out the right internal carotid artery (arrow) and impinging on the ipsilateral cavernous sinus.
30
Phadke et al
Figure 3. Section from the tumor shows heavily calcified, mature glial tissue. (High-power magnification.)
sue, salivary type serous acini (elements unrelated to normal anatomic structures in the middle ear region), glandular spaces, and mature glial tissue arranged in an organoid fashion confirmed the diagnosis of mature teratoma in our case. At this stage, a radiologic review confirmed the features of a teratoma as well. The understanding of the natural history of intracranial teratomas is still incomplete partly because of the low incidence.11,12 However these are not merely quiescent malformations, but display a degree of progressive disorganized growth and are
Figure 4. Section from the tumor shows tall columnar epithelium, mature adipose tissue, and mature glial tissue closely juxtaposed in an organoid fashion. (Medium power magnification.)
capable of invading adjacent normal tissue as a result of their increasing size.9 In the present case, although the patient was symptomatic since birth, he experienced accelerated symptoms over a relatively short period of a few days, in early adulthood. This could be ascribed to the tumor growing steadily over a period of several years and producing dramatic symptoms, once it impinged on and compressed the ipsilateral cavernous sinus. Teratomas may secondarily extend into the middle cranial fossa. Cases of the tumor have arisen in the petrous apex9 or the cavernous sinus7 and
Teratoma Arising From the Middle Cranial Fossa
31
Figure 5. Section from the tumor shows salivary type serous acini (arrow) and mature glial tissue in close juxtaposition. (Scanning magnification.)
subsequently extended into the middle cranial fossa. In the present case, the tumor mostly occupied the middle cranial fossa, although it extended up to the cavernous sinus and the foramen lacerum and also produced scalloping of the temporal bone with extension into the infratemporal fossa and the middle ear. However, when the tumor attains a large size within the cranial cavity, as in the present case, the precise anatomic site of origin might be impossible to ascertain. A tumor arising within the middle cranial fossa is located in a relatively inaccessible area within the skull and a complete extirpation might not be possible. In such cases, the surgical procedure must achieve adequate decompression and ensure tissue for the histopathologic diagnosis. A definitive histopathologic diagnosis would avoid potential overtreatment or under-treatment. Mature teratomas are benign and usually radioresistant.13 Radical excision is advocated despite the benign nature because the long-term outcome is excellent after such treatment. In the present case, surgical decompression was achieved following sub-total excision of the tumor given its relatively inaccessible location and large size. The long-term prognosis for intracranial mature teratomas is excellent, with the 10-year survival being as high as 93% in one large series.14 References 1. Nishioka H, Ito H, Haraoka J, et al: Immature teratoma originating from the pituitary gland. Case Report. Neurosurgery 1999;44:644-647
2. Merchut MP, Biller J, Ghobrial M, et al: Adult intrasellar teratoid tumor. J Clin Neuroophthalmol 1986;6:175-180 3. Ng HK, Poon WS, Chan YL: Basal ganglia teratomas: Report of three cases. Aust N Z Surg 1992;62:436-440 4. Selcuki M, Attar A, Yuceer N, et al: Mature teratoma of the lateral ventricle: Report of two cases. Acta Neurochir 1998; 140:171-174 5. Drapkin AJ, Rose WS, Pellmar MB: Mature teratoma in the fourth ventricle of an adult. Neurosurgery 1987;21:404410 6. Nishigaya K, Uneo T, Satou E, et al: Mature teratoma incidentally found in the sylvian fissure: A report of an autopsy case. Noshuyo Byori 1994;11:131-134 7. Tobias S, Valarezo J, Meir K, et al: Giant cavernous sinus teratoma: A clinical example of a rare entity: Case report. Neurosurgery 2001;48:1370-1371 8. Muzumdar D, Goel A, Desai K, et al: Mature teratoma arising from the sella. Case Report. Neurol Med Chir 2001;41: 356-359 9. Behnke EE, Schindler R: Dermoid of the petrous apex. Laryngoscope 1984;94:779-783 10. Gyure KA, Thompson LDR, Morrison AL: A clinicopathological study of 15 patients with neuroglial heterotopias and encephalocoeles of the middle ear and mastoid region. Laryngoscope 2000;110:1731-1735 11. Takei Y, Pearl GS: Ultrastructural study of intracranial yolk sac tumor: With special reference to the oncogenic phylogeny of germ cell tumors. Cancer 1981;48:2038-2046 12. Teilum G: Classification of endodermal sinus tumor (mesoblastoma vitellinum) and so called “embryonal carcinoma” of the ovary. Acta Pathol Microbiol Scand 1965;64:407429 13. Matsutani M, Sano K, Takakura K, et al: Primary intracranial germ cell tumors. A clinical analysis of 153 histologically verified cases. J Neurosurg 1997;86:446-455 14. Sano K: Pathogenesis of intracranial germ cell tumors reconsidered. J Neurosurg 1999;90:258-264
Mature Teratoma Arising From the Middle Cranial Fossa Rahul S. Phadke, MD, Asha S. Shenoy, MD, Anjana Hosangadi, MD, and Trimurti D. Nadkarni, MS A 25-year-old man presented with a sudden spurt in size of a bony swelling around the external ear, which was present since birth. This was associated with a painful swelling of the right half of the face and pain, redness, and decreased vision in the right eye. Neurologic examination showed decreased visual acuity in the right eye and paresis of the fifth, seventh, and eighth cranial nerves. Neuroimaging showed an extra-axial, partly cystic tumor of mixed density, located entirely within the middle cranial fossa scalloping the temporal bone and extending into the right infratemporal fossa and the right middle ear and impinging on the ipsilateral cavernous sinus. The right temporal lobe was elevated and compressed. Histopathologic examination confirmed a mature teratoma. Ann Diagn Pathol 8: 28-31, 2004. © 2004 Elsevier Inc. All rights reserved. Index Words: Mature teratoma, middle cranial fossa, extra axial, cavernous sinus
A
25-year-old man presented with a history of a bony swelling around the right external ear and drooping of the right eyelid since birth. Recently, he had noticed an increase in the size of the swelling over the past few days. This was coupled with swelling of the right half of the face and pain, redness, and decreased vision in the right eye. Neurologic examination showed decreased visual acuity in the right eye and a corneal opacity. Fundoscopy showed a markedly congested optic disc with absent venous pulsations. There was paresis of the fifth, seventh, and eighth cranial nerves. The lower cranial nerves were normal. There was no motor deficit or any cerebellar signs. Computerized tomography of the brain showed an extra-axial, well-defined, low-attenuated, hypodense, lobulated, and partly cystic tumor within the middle cranial fossa, with a central calcified component and peripheral fat density (Fig 1). The tumor produced scalloping of the petrous and squamous portions of the temporal bone. Anteriorly, it extended up to the cavernous sinus and the foramen lacerum. The right temporal lobe was
From the Departments of Pathology and Neurosurgery, Seth G.S. Medical College and K.E.M. Hospital, Mumbai. Address reprint requests to Rahul S. Phadke, MD, Department of Histopathology, St Thomas’ Hospital, 2nd Floor, North Wing, Lambeth Palace Road, London SE1 7EH UK. © 2004 Elsevier Inc. All rights reserved. 1092-9134/04/0801-0005$30.00/0 doi:10.1016/j.anndiagpath.2003.11.003
28
elevated and compressed. Magnetic resonance imaging of the brain showed a large, partly cystic tumor of mixed density, with areas of calcification. The right internal carotid artery and the right middle cerebral artery were stretched out with compression of the ipsilateral cavernous sinus (Fig 2). The tumor extended into the right infratemporal fossa and the right middle ear. There was no extension into the brain parenchyma. A right temporo-basal craniectomy with subtotal excision of a partly cystic tumor was performed. The postoperative course was uneventful. There was persistent fifth, seventh, and eighth nerve paresis. The lower cranial nerves were normal. Subsequent follow-up data were unavailable. The tumor was received as multiple soft tissue bits aggregating five cm. Most bits were grayish and soft. Some bits had a gritty consistency. A few membranous bits were noted. Some tissue bits had a hemorrhagic appearance. Histopathologic examination of multiple tissue sections showed most tissue bits to be composed of mature glial tissue, with widespread calcification within (Fig 3). Some of the larger calcific deposits resembled calcospherules. The deposits were mainly perivascular in location. Some tissue bits were lined by flattened to cuboidal epithelial cells, some of which contained a melanin-like pigment. Glandular spaces lined by similar epithelium were embedded within the glial tissue. Also seen were tissue bits lined by tall columnar gastric-type epithelium beneath which were mature adipose tissue (Fig 4), salivary type sero-
Annals of Diagnostic Pathology, Vol 8, No 1 (February), 2004: pp 28-31
Teratoma Arising From the Middle Cranial Fossa
Figure 1. Computed tomography shows an extra-axial tumor of mixed density, with central calcification (arrow), arising within the right middle cranial fossa.
mucinous acini (Fig 5), glandular spaces lined by flattened to cuboidal epithelium, and mature glial tissue were closely juxtaposed in an organoid fashion. There were no immature elements or any malignant component. Fibrocollagenous bits, possibly representing dura, were seen. These histopathologic features suggested a mature teratoma.
29
poral bone and extending into the middle ear, the initial radiologic diagnoses considered were aneurysmal bone cyst, giant cell tumor, or epidermoid cyst. The clinical impression was that of a choleasteatoma. Histopathologic examination ruled out these possibilities. The main differential diagnoses considered were glial heterotopia/encephalocoele versus teratoma. Pathologically, there are no significant differences between neuroglial heterotopia and encephalocoele in the middle ear region. Both are characterized by varying proportions of neurons and glia, with associated chronic inflammation and gliosis.10 Depending on the presence or absence of a central nervous system connection, either heterotopia or encephalocoele may be the appropriate terms for these lesions. The absence of any parenchymal connection ruled out an encephalocoele in the present case. Most middle ear heterotopias/encephalocoeles are characterized by presence of flattened to cuboidal epithelium and glandular elements most likely representing entrapped tympanic cavity or eustachian tube epithelium and need to be differentiated from teratomatous elements.10 The presence of tumor bits composed of gastric-type epithelium, adipose tis-
Discussion Teratomas may be classified as mature or immature depending on the degree of differentiation of their component tissues. Mature teratomas are identified by the presence of fully differentiated elements derived from all three germinal layers. Intracranial teratomas are rare, comprising 0.5% of all intracranial neoplasms.1 Most examples occur in a midline location in the pineal region followed by the suprasellar/hypothalamic region.1,2 Non-midline cases are rare, and occasional cases are reported to occur in the basal ganglia, lateral ventricle, fourth ventricle, Sylvian fissure, cavernous sinus, sella, and the temporal bone.3-9 Such rare cases can present considerable diagnostic challenge, and a thorough reappraisal of the clinical presentation, radiologic features, and histopathology is essential to arrive at an accurate diagnosis. In the present case, with an extra-axial, partly cystic middle cranial fossa lesion partly eroding the tem-
Figure 2. Magnetic resonance imaging of the brain shows an extra-axial tumor of mixed density stretching out the right internal carotid artery (arrow) and impinging on the ipsilateral cavernous sinus.
30
Phadke et al
Figure 3. Section from the tumor shows heavily calcified, mature glial tissue. (High-power magnification.)
sue, salivary type serous acini (elements unrelated to normal anatomic structures in the middle ear region), glandular spaces, and mature glial tissue arranged in an organoid fashion confirmed the diagnosis of mature teratoma in our case. At this stage, a radiologic review confirmed the features of a teratoma as well. The understanding of the natural history of intracranial teratomas is still incomplete partly because of the low incidence.11,12 However these are not merely quiescent malformations, but display a degree of progressive disorganized growth and are
Figure 4. Section from the tumor shows tall columnar epithelium, mature adipose tissue, and mature glial tissue closely juxtaposed in an organoid fashion. (Medium power magnification.)
capable of invading adjacent normal tissue as a result of their increasing size.9 In the present case, although the patient was symptomatic since birth, he experienced accelerated symptoms over a relatively short period of a few days, in early adulthood. This could be ascribed to the tumor growing steadily over a period of several years and producing dramatic symptoms, once it impinged on and compressed the ipsilateral cavernous sinus. Teratomas may secondarily extend into the middle cranial fossa. Cases of the tumor have arisen in the petrous apex9 or the cavernous sinus7 and
Teratoma Arising From the Middle Cranial Fossa
31
Figure 5. Section from the tumor shows salivary type serous acini (arrow) and mature glial tissue in close juxtaposition. (Scanning magnification.)
subsequently extended into the middle cranial fossa. In the present case, the tumor mostly occupied the middle cranial fossa, although it extended up to the cavernous sinus and the foramen lacerum and also produced scalloping of the temporal bone with extension into the infratemporal fossa and the middle ear. However, when the tumor attains a large size within the cranial cavity, as in the present case, the precise anatomic site of origin might be impossible to ascertain. A tumor arising within the middle cranial fossa is located in a relatively inaccessible area within the skull and a complete extirpation might not be possible. In such cases, the surgical procedure must achieve adequate decompression and ensure tissue for the histopathologic diagnosis. A definitive histopathologic diagnosis would avoid potential overtreatment or under-treatment. Mature teratomas are benign and usually radioresistant.13 Radical excision is advocated despite the benign nature because the long-term outcome is excellent after such treatment. In the present case, surgical decompression was achieved following sub-total excision of the tumor given its relatively inaccessible location and large size. The long-term prognosis for intracranial mature teratomas is excellent, with the 10-year survival being as high as 93% in one large series.14 References 1. Nishioka H, Ito H, Haraoka J, et al: Immature teratoma originating from the pituitary gland. Case Report. Neurosurgery 1999;44:644-647
2. Merchut MP, Biller J, Ghobrial M, et al: Adult intrasellar teratoid tumor. J Clin Neuroophthalmol 1986;6:175-180 3. Ng HK, Poon WS, Chan YL: Basal ganglia teratomas: Report of three cases. Aust N Z Surg 1992;62:436-440 4. Selcuki M, Attar A, Yuceer N, et al: Mature teratoma of the lateral ventricle: Report of two cases. Acta Neurochir 1998; 140:171-174 5. Drapkin AJ, Rose WS, Pellmar MB: Mature teratoma in the fourth ventricle of an adult. Neurosurgery 1987;21:404410 6. Nishigaya K, Uneo T, Satou E, et al: Mature teratoma incidentally found in the sylvian fissure: A report of an autopsy case. Noshuyo Byori 1994;11:131-134 7. Tobias S, Valarezo J, Meir K, et al: Giant cavernous sinus teratoma: A clinical example of a rare entity: Case report. Neurosurgery 2001;48:1370-1371 8. Muzumdar D, Goel A, Desai K, et al: Mature teratoma arising from the sella. Case Report. Neurol Med Chir 2001;41: 356-359 9. Behnke EE, Schindler R: Dermoid of the petrous apex. Laryngoscope 1984;94:779-783 10. Gyure KA, Thompson LDR, Morrison AL: A clinicopathological study of 15 patients with neuroglial heterotopias and encephalocoeles of the middle ear and mastoid region. Laryngoscope 2000;110:1731-1735 11. Takei Y, Pearl GS: Ultrastructural study of intracranial yolk sac tumor: With special reference to the oncogenic phylogeny of germ cell tumors. Cancer 1981;48:2038-2046 12. Teilum G: Classification of endodermal sinus tumor (mesoblastoma vitellinum) and so called “embryonal carcinoma” of the ovary. Acta Pathol Microbiol Scand 1965;64:407429 13. Matsutani M, Sano K, Takakura K, et al: Primary intracranial germ cell tumors. A clinical analysis of 153 histologically verified cases. J Neurosurg 1997;86:446-455 14. Sano K: Pathogenesis of intracranial germ cell tumors reconsidered. J Neurosurg 1999;90:258-264