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Magnetic resonance imaging and computed tomography of an intraventricular craniopharyngioma
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CLINICAL IMAGING 1990;14:116-119
MAGNETIC RESONANCE IMAGING AND COMPUTED TOMOGRAPHY OF AN INTRAVENTRICULAR CRANIOPHARYNGIOMA MICHAEL SACHER, MD, ROBIN I. GOTTESMAN, MD, ALLEN S. ROTHMAN, MD, BRUCE R. ROSENBLUM, MD, AND MICHAEL S. HANDLER, MD’
The computed tomography (CT) and magnetic resonance imaging (MRI) appearances ofan intraventricular craniopharyngioma are discussed. The unusual CT appearance of our case is compared to the previous 13 cases in the CT literature. The MRI scan represents the only known description ofan intraventricular craniopharyngioma in the current literature. The characteristics of our case are compared to the MRI appearance of suprasellar craniopharyngiomas. KEY WORDS:
Craniopharyngioma; Intraventricular; Third ventricle; Computed tomography; Magnetic resonance imaging scan
Intraventricular craniopharyngiomas are rare lesions with only 13 cases previously reported in the computed tomography (CT) literature. Our case is the first magnetic resonance imaging (MRI) demonstration of such a tumor. The lesion we describe is atypical in appearance when compared with previously reported CT cases of intraventricular craniopharyngiomas and MIU cases of the more commonly located suprasellar craniopharyngiomas.
From the Departments of Radiology (M.S., R.I.G.) Neurosurgery (A.S.R., B.R.R.), and Pathology (M.S.H.) of the Mount Sinai Medical Center of CUNY, New York, New York. Address reprint requests to: Michael Sacher, MD, Department of Radiology, Box 1234, Mount Sinai Hospital, One Gustave L. Levy Place, New York, NY 10029. Received November 27, 1989. 0 1990 by Elsevier Science Publishing Co., Inc. 655 Avenue of the Americas, New York, NY 10010 0899/7071/90/$3.50
CASE REPORT A 34year-old male presented with a several month history of worsening bifrontal headaches, unrelated to the time of day or level of activity. There was no visual disturbance, endocrine related abnormality, or intellectual impairment. Neurologic examination was normal. Laboratory values were all within normal limits. A CT scan demonstrated a noncalcified cysticappearing lesion with an area of enhancement anteroinferiorly (Figures 1 and 2). The lesion extended superiorly to the foramen of Monro resulting in secondary obstructive hydrocephalus (Figure 3). MRI was subsequently performed and showed an intraventricular tumor which appeared hypointense on Tl-weighted images (Figure 4) and hyperintense on T&weighted images (Figure 5). A bifrontoparietal craniotomy was performed followed by microsurgical, transcallosal opening of the lateral ventricle. A large cyst comprising almost the entire mass and containing xanthochromic fluid was aspirated through the foramen of Monro. The cyst walls were then excised. Deep to the cyst a soft, vascular-appearing solid tumor was peeled from the floor of the third ventricle. Pathologic sections of the tumor revealed craniopharyngioma (Figure 6).
DISCUSSION Craniopharyngiomas arise from squamous epithelial rests of Rathke’s pouch, usually along the pituitary stalk and tuber cinereum. Although most of these tumors are located within the suprasellar cistern and sellar region, rare instances of lesions isolated to the third ventricle have been reported. These are be-
MAY 1990
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strated a cystic, noncalcified mass with a small enhancing portion. The cystic CT appearance is therefore unusual as compared to previous reports of intraventricular craniopharyngiomas (2, 3, 5). The MRI appearance of craniopharyngiomas has previously been described. The craniopharyngiomas have a variable appearance on Tl-weighted images corresponding to the pathologic nature of these lesions. In the series of 20 patients studied by Pusey et al., approximately half showed increased signal on Tl-weighted images. Lesions with high intensity signal on Tl-weighted images were found to correspond to either a high liquid cholesterol content or to the presence of methemoglobin. Moderate signal intensity on Tl-weighted images was seen in the absence of high cholesterol content or methemoglobin. In all cases, the T2-weighted images demonstrated a high signal intensity. One unusual case did show low intensity signal on Tl and T2 corresponding to a cystic tumor with a high keratin content and delicate bony trabeculae (6). Our case demonstrated a predominantly cystic lesion on CT with low signal intensity on Tl-weighted images. An area of increased density on CT corresponded to a small region of isointensity on MRI and was felt to reflect the solid portion of this mass. The FIGURE 1. A contrast-enhanced axial CAT scan shows an enhancing third ventricular tumor with evidence of obstructive hydrocephalus.
lieved to arise from squamous rests within the floor of the third ventricle or the region of the lamina terminalis (l-3). Craniopharyngiomas comprise approximately 3% of intracranial neoplasms in the general population. Although generally seen in childhood or young adulthood, presentation in middle age or later in life is not uncommon. Patients with suprasellar cistern tumors may present with endocrinopathies (50% of patients), most frequently diabetes insipidus, and/or with optic nerve or chiasm compression. Patients with tumors confined to the third ventricle may complain only of headache or increasing dementia due to obstructive hydrocephalus. Craniopharyngiomas are cystic in 50 to 60% of cases, mixed cystic and solid in 3O%, and entirely solid in 14%. Tumoral calcification is seen in approximately 75% of cases (3). Interestingly, all but two previously reported cases of intraventricular craniopharyngiomas have been solid noncalcified enhancing masses (4). In the present case the CT scan demon-
FIGURE 2. A contrast-enhanced CT scan in the coronal plane shows the intraventricular tumor with enhancement of its inferior portion.
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FIGURE 5. A T2-weighted (0.5 T, TR = 2500, TR = 110) sagittal MRI scan shows the tumor to have a high signal intensity.
FIGURE 3. A higher slice shows the nonenhancing portion of the tumor at the level of the foramen of Monro associated with obstructive hydrocephalus.
FIGURE 4. A Tl-weighted (0.5 T, TR = 400, TE = 30) sagittal MRI scan shows an intra-third-ventricular tumor. The larger cystic portion is of decreased signal intensity; the arteroinferior solid portion is of intermediate intensity.
FIGURE 6. A representative photomicrograph shows regular columnar epithelium on a thin basement membrane and subjacent stellate cells consistent with craniopharyngioma (magnification 10X).
MAY 1990
T2-weighted images showed uniformly increased signal intensity as was seen in the majority of previously described suprasellar craniopharyngiomas (6). We cannot be certain as to why the cystic portion of our lesion appeared low in signal intensity on the Tl-weighted images as opposed to those cases in the series by Pusey et al., where the cystic lesions demonstrated medium-to-high signal intensity on similar sequences. There was no evidence of ossified trabeculae in our case as had been noted in the single case with low signal intensity on Tl (and also on T2) described by Pusey et al. (6). We feel that low intracystic cholesterol and protein content with absence of significant methemoglobin concentration best explains the cerebrospinal fluid like characteristics of this predominantly cystic lesion (6,7). In summary, this case is of interest in that it is the first known report of an intraventricular craniopharyngioma in the MRI literature (6). This mass demonstrated atypical MRI characteristics as compared to previously described suprasellar craniopharyngiomas (6). Additionally, its CT appearance was un-
INTRAVENTRICULAR CRANIOPHARYNGIOMA
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usual in that this intraventricular craniopharyngioma to the solidwas mostly cystic in contradistinction described in this loappearing lesions previously cation.
REFERENCES 1. Rush JL, Kusske JA, DeFeo DR, Pribam HW. Intraventricular craniopharyngioma. Neurology 1975;25:1094-1096 2. Matthews FD. Intraventricular craniopharyngioma. AJNR 1983;4:984-985. 3. Goldstein SJ, Wilson DD, Young AB, Guidry GJ. Craniopharyngioma intrinsic to the third ventricle. Surg Neurol 1983;20:249-253. 4. Lanzieri CF, Sacher M, Som P. CT changes in the septum pellucidum associated with intraventricular craniopharyngiomas. Comput Assist Tomogr 1985;9:507-510. 5. Cashion EL, Young JM. Intraventricular craniopharyngioma. J Neurosurg 1971;34:84-87. 6. Pusey E, Kortman KF,, Flannigan BD, Tsuruda J, Bradley WG. MR of craniopharyngiomas: tumor delination and characterization AJNR 1987;8:439-444. 7. Braun IF, Pinto RS, Epstein omas. AJNR 1982;3:139-141.
F. Dense cystic craniopharyngi-
CLINICAL IMAGING 1990;14:116-119
MAGNETIC RESONANCE IMAGING AND COMPUTED TOMOGRAPHY OF AN INTRAVENTRICULAR CRANIOPHARYNGIOMA MICHAEL SACHER, MD, ROBIN I. GOTTESMAN, MD, ALLEN S. ROTHMAN, MD, BRUCE R. ROSENBLUM, MD, AND MICHAEL S. HANDLER, MD’
The computed tomography (CT) and magnetic resonance imaging (MRI) appearances ofan intraventricular craniopharyngioma are discussed. The unusual CT appearance of our case is compared to the previous 13 cases in the CT literature. The MRI scan represents the only known description ofan intraventricular craniopharyngioma in the current literature. The characteristics of our case are compared to the MRI appearance of suprasellar craniopharyngiomas. KEY WORDS:
Craniopharyngioma; Intraventricular; Third ventricle; Computed tomography; Magnetic resonance imaging scan
Intraventricular craniopharyngiomas are rare lesions with only 13 cases previously reported in the computed tomography (CT) literature. Our case is the first magnetic resonance imaging (MRI) demonstration of such a tumor. The lesion we describe is atypical in appearance when compared with previously reported CT cases of intraventricular craniopharyngiomas and MIU cases of the more commonly located suprasellar craniopharyngiomas.
From the Departments of Radiology (M.S., R.I.G.) Neurosurgery (A.S.R., B.R.R.), and Pathology (M.S.H.) of the Mount Sinai Medical Center of CUNY, New York, New York. Address reprint requests to: Michael Sacher, MD, Department of Radiology, Box 1234, Mount Sinai Hospital, One Gustave L. Levy Place, New York, NY 10029. Received November 27, 1989. 0 1990 by Elsevier Science Publishing Co., Inc. 655 Avenue of the Americas, New York, NY 10010 0899/7071/90/$3.50
CASE REPORT A 34year-old male presented with a several month history of worsening bifrontal headaches, unrelated to the time of day or level of activity. There was no visual disturbance, endocrine related abnormality, or intellectual impairment. Neurologic examination was normal. Laboratory values were all within normal limits. A CT scan demonstrated a noncalcified cysticappearing lesion with an area of enhancement anteroinferiorly (Figures 1 and 2). The lesion extended superiorly to the foramen of Monro resulting in secondary obstructive hydrocephalus (Figure 3). MRI was subsequently performed and showed an intraventricular tumor which appeared hypointense on Tl-weighted images (Figure 4) and hyperintense on T&weighted images (Figure 5). A bifrontoparietal craniotomy was performed followed by microsurgical, transcallosal opening of the lateral ventricle. A large cyst comprising almost the entire mass and containing xanthochromic fluid was aspirated through the foramen of Monro. The cyst walls were then excised. Deep to the cyst a soft, vascular-appearing solid tumor was peeled from the floor of the third ventricle. Pathologic sections of the tumor revealed craniopharyngioma (Figure 6).
DISCUSSION Craniopharyngiomas arise from squamous epithelial rests of Rathke’s pouch, usually along the pituitary stalk and tuber cinereum. Although most of these tumors are located within the suprasellar cistern and sellar region, rare instances of lesions isolated to the third ventricle have been reported. These are be-
MAY 1990
INTRAVENTRICULAR
CRANIOPHARYNGIOMA
117
strated a cystic, noncalcified mass with a small enhancing portion. The cystic CT appearance is therefore unusual as compared to previous reports of intraventricular craniopharyngiomas (2, 3, 5). The MRI appearance of craniopharyngiomas has previously been described. The craniopharyngiomas have a variable appearance on Tl-weighted images corresponding to the pathologic nature of these lesions. In the series of 20 patients studied by Pusey et al., approximately half showed increased signal on Tl-weighted images. Lesions with high intensity signal on Tl-weighted images were found to correspond to either a high liquid cholesterol content or to the presence of methemoglobin. Moderate signal intensity on Tl-weighted images was seen in the absence of high cholesterol content or methemoglobin. In all cases, the T2-weighted images demonstrated a high signal intensity. One unusual case did show low intensity signal on Tl and T2 corresponding to a cystic tumor with a high keratin content and delicate bony trabeculae (6). Our case demonstrated a predominantly cystic lesion on CT with low signal intensity on Tl-weighted images. An area of increased density on CT corresponded to a small region of isointensity on MRI and was felt to reflect the solid portion of this mass. The FIGURE 1. A contrast-enhanced axial CAT scan shows an enhancing third ventricular tumor with evidence of obstructive hydrocephalus.
lieved to arise from squamous rests within the floor of the third ventricle or the region of the lamina terminalis (l-3). Craniopharyngiomas comprise approximately 3% of intracranial neoplasms in the general population. Although generally seen in childhood or young adulthood, presentation in middle age or later in life is not uncommon. Patients with suprasellar cistern tumors may present with endocrinopathies (50% of patients), most frequently diabetes insipidus, and/or with optic nerve or chiasm compression. Patients with tumors confined to the third ventricle may complain only of headache or increasing dementia due to obstructive hydrocephalus. Craniopharyngiomas are cystic in 50 to 60% of cases, mixed cystic and solid in 3O%, and entirely solid in 14%. Tumoral calcification is seen in approximately 75% of cases (3). Interestingly, all but two previously reported cases of intraventricular craniopharyngiomas have been solid noncalcified enhancing masses (4). In the present case the CT scan demon-
FIGURE 2. A contrast-enhanced CT scan in the coronal plane shows the intraventricular tumor with enhancement of its inferior portion.
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FIGURE 5. A T2-weighted (0.5 T, TR = 2500, TR = 110) sagittal MRI scan shows the tumor to have a high signal intensity.
FIGURE 3. A higher slice shows the nonenhancing portion of the tumor at the level of the foramen of Monro associated with obstructive hydrocephalus.
FIGURE 4. A Tl-weighted (0.5 T, TR = 400, TE = 30) sagittal MRI scan shows an intra-third-ventricular tumor. The larger cystic portion is of decreased signal intensity; the arteroinferior solid portion is of intermediate intensity.
FIGURE 6. A representative photomicrograph shows regular columnar epithelium on a thin basement membrane and subjacent stellate cells consistent with craniopharyngioma (magnification 10X).
MAY 1990
T2-weighted images showed uniformly increased signal intensity as was seen in the majority of previously described suprasellar craniopharyngiomas (6). We cannot be certain as to why the cystic portion of our lesion appeared low in signal intensity on the Tl-weighted images as opposed to those cases in the series by Pusey et al., where the cystic lesions demonstrated medium-to-high signal intensity on similar sequences. There was no evidence of ossified trabeculae in our case as had been noted in the single case with low signal intensity on Tl (and also on T2) described by Pusey et al. (6). We feel that low intracystic cholesterol and protein content with absence of significant methemoglobin concentration best explains the cerebrospinal fluid like characteristics of this predominantly cystic lesion (6,7). In summary, this case is of interest in that it is the first known report of an intraventricular craniopharyngioma in the MRI literature (6). This mass demonstrated atypical MRI characteristics as compared to previously described suprasellar craniopharyngiomas (6). Additionally, its CT appearance was un-
INTRAVENTRICULAR CRANIOPHARYNGIOMA
119
usual in that this intraventricular craniopharyngioma to the solidwas mostly cystic in contradistinction described in this loappearing lesions previously cation.
REFERENCES 1. Rush JL, Kusske JA, DeFeo DR, Pribam HW. Intraventricular craniopharyngioma. Neurology 1975;25:1094-1096 2. Matthews FD. Intraventricular craniopharyngioma. AJNR 1983;4:984-985. 3. Goldstein SJ, Wilson DD, Young AB, Guidry GJ. Craniopharyngioma intrinsic to the third ventricle. Surg Neurol 1983;20:249-253. 4. Lanzieri CF, Sacher M, Som P. CT changes in the septum pellucidum associated with intraventricular craniopharyngiomas. Comput Assist Tomogr 1985;9:507-510. 5. Cashion EL, Young JM. Intraventricular craniopharyngioma. J Neurosurg 1971;34:84-87. 6. Pusey E, Kortman KF,, Flannigan BD, Tsuruda J, Bradley WG. MR of craniopharyngiomas: tumor delination and characterization AJNR 1987;8:439-444. 7. Braun IF, Pinto RS, Epstein omas. AJNR 1982;3:139-141.
F. Dense cystic craniopharyngi-