Computcrircd Medical Imqing aM Graphics. Vol. IS. No. 6, pp. 415421. tinted in the USA. All rights nswwd.
0895-fd11/91 s3.M) + .oo Copyright 0 1991 PerSamonPress plc
1991
MRI FINDINGS OF HYPOTHALAMIC HAMARTOMA: REPORT OF FIVE CASES AND REVIEW OF THE LITERATURE Antonio Lona Soto, MutsumasaTakahashi”,YasuyukiYamashita, Yuji Sakamoto,JintetsuShinzatoand KazuhiroYoshizumi Department of Radiology,
Kumamoto
University (Received
School of Medicine, 26 December
l-l-l
Honjo, Kumamoto
860, Japan
1990)
Abstract-Hypothalamic hamartuma is a relatively rare congenital malformation, associated with the clinical present@ion of precocious puberty of central type. Five cases with hypothalamic hamartoma are reported here, with an emphasis on MR appearance. The most common presentation of hypothalamic hamartuma was a small and ?wII defined mass in the inferior aspect of the hypothalamus, showing isointensity on Tl weighted images and IQperintensity on T2 weighted images compared with the gray matter. The previous reports with MRI description are reviewed and compared with the present results. Key Words: Brain anomaly, Brain tumor, Hamartoma, Hypothalamus,
INTRODUCTION
TE/excitations); for the 0.5T unit, Tl weighted image with 550/30/2 and T2 weighted images with 1600/ 100/2; and for the 1.5 T unit, Tl weighted image with 600/15-2 and T2 weighted image with 2300/90/l. Three patients underwent a surgery with histological confirmation of HH, whereas two patients received medical treatment. The diagnosis in the last two cases was based on the hormonal test of luteinizing hormone (LH) and stimulation of LH release hormone with confirmation of the lesion by MR studies. Sag&al Tl and T2 weighted images were obtained in most instances and in selected cases coronal or axial planes were added. In case 1 and case 2, a presurgical MR examination was performed. In case 2 and case 3, postsurgical MR studies were available. In two medically treated cases, seven MR examinations were performed with an interval of about 1 year. In these cases we performed follow-up studies for 3 and 4 years. Table 1 summarizes the clinical information of our patients.
Hypothalamic hamartoma (HI-I) is a congenital malformation composed of ectopic neuronal tissue, the origin of the mass being in the inferior aspect of the hypothalamus between the mammillary bodies and pituitary stalk. The mass usually projects into the subarachnoid space by filling the interpeducular, prepontine and/or suprasellar cisterns. The most frequent clinical presentation is precocious puberty (PP) within the first 2 or 3 years of life in about 70 to 90% of the cases (1, 2). Other associated symptoms include laughing seizures, mental retardation and tonic clonic convulsion. We evaluated magnetic resonance (MR) findings in five cases of HH and compared them with the previously reported cases in the literature. METHODS
MR Imaging
AND MATERIALS
The MR findings of five cases with the diagnosis of I-II-I were reviewed. Eleven MR examinations on these cases were performed on three different MR units: a 0.22 T resistive unit (MRT-22A, Toshiba Medical Systems); a 0.5 T superconductive unit (Gyroscan S-5, Philips Medical Systems) and a 1.5 T superconductive unit (Magnetom 15 T, Siemens-Asahi Medical Systems). Pulse sequences used were as follows: for the 0.22 T unit, Tl weighted images with 400-500/40/4 and T2 weighted images with 1660-2000/60-80/2 (tr/
RESULTS HH was recognized by the presence of a small and well defined mass with apparent origin in the inferior aspect of the hypothalamus, projecting into the interpeduncular, suprasellar and/or prepontine cisterns. Tl weighted images showed the mass to be homogeneous and isointense with the gray matter in all patients. The lesion was better delineated on T2 weighted images with homogeneous high signal intensity in four cases. In case 4 (Pig. l), the lesion was isointense with the cortex on T2 weighted images.
*To whom all correspondence should be addressed. 415
416
Computerized Medical Imaging and Graphics
November-December/l99 1, Volume 15, Nwnber 6
(b) Fig. 1. A Syear-old female (Case 5). (a) Sagittal Tl weighted image on admission. A small hypothalamic hamartoma ilsointenseto the cortex is observed (arrowheads). (b) Sagittal Tl weighted images at 3 years after first MRI.
Case 2 showed the biggest lesion (3.8 X 2.7 cm) in the sag&al section with slight compression of the pons. The mass effect diminished after the surgery (Fig. 2). The smallest lesion was 1.0 X 1.2 cm in the sag&al plane in case 3. The image quality with the 1.5 T unit was superior to that of 0.5 T and 0.22 T units. How-
ever, the detectability and demonstration of the lesion were not significantly different. In serial studies with three different units, the lesion did not show any change in signal intensity. In these two medically treated cases, the mass did not show any change in size, shape or signal intensity in the period of 3 and 4 years (Figs. 1
417
MRI of hypothalamic hamartoma . A. L. So’ro et al.
Fig. 1. (continued)
(c) Sagittal T2 weighted images at 3 years after fmt MRI. The lesion shows same size and signal intensity after 3 years of follow-up (arrowheads).
and 3). In addition, in case 5 Gd-DTPA was administered and the lesion did not show contrast enhancement (Fig. 3c). The clinical course of the three surgically treated patients did not show significant improvement after surgery. The symptoms of PP were moderately controlled in medically treated cases. DISCUSSION HH is recognized as the most common lesion associated with PP of central type (2, 3). The mechanism of PP has not been well established. Two theories have
been proposed, mechanical compression over the hypothalamus with loss of the inhibitory effects on the release of gonadotropin (4) and direct neuronal co~ection with production of the hormones by the lesion. The value of MRI in demonstration of HH has been described by other authors (5-12). We found 18 cases of HH in the literature with MRI description. Ten of these cases showed isointensity on Tl weighted images and hyperintensity on T2 weighted images in relation to the cortex (5-8). This finding was consistent with our observations in four of five cases in our series. BeningEeld et al. (9) and Hubbard et al. (10) described four cases with isointensity on both Tl and T2 weight-
Table 1. Diagnosis, clinical manifestations CaSe No.
Sex
Age of initial diagnosis
1
M
2
M
3
and MRI findings. MRI Intensity
Clinical presentation
MRI examination
TlWI
T2w.I
Treatment
2 years
PP, mental retardation
Pre-surgery
Is0
High
Sw9ry
2 years
PP, laughing seizures, tonicclonic convulsion
Pre- and Postswery
Is0
High
-Qwry
M
1 year
PP
Post-surgery
Is0
High
4
F
3 years
9years
PP
Follow-up 4 years
IS0
5
F
1 year
5 years
PP
Follow-up 3 years
IS0
w& Is0
swery Medical
PP = Precocious puberty
Resent age
retardation
Medical
418
Computerized
Medical
Imaging
and Graphics
November-December/l991,
Volume
15, Number
6
(4
Fig. 2. A 2-year-old male (Case 2). (a) Sag&al T2 weighted image before surgery. There is a hyperintense signal lesion in the suprasellarcistern, prepontine cistern and hypothalamus (arrowheads). Note the slight compression of the pons. (b) Sagittal Tl weighted image (postsurgery). The hamartoma is isointense and homogeneous, while the masseffect decreased(arrowheads).
ed images. In our series one case showed such findhi! IS. Other authors (11, 12) reported the mass to be hylFrtense on Tl and T2 weighted images. However, we did not have such a finding in our series. We did no1 : find any good explanation for such a discrepancy. Ho lwever, the histological description in surgical cases
(5, 12, 14) revealed different amount and type :s of neuronal and glial cells. On the other hand, the amiount of myelin may be different in neuronal cells. These tW0 findings could explain the different signal intenr rities seen in these patients. The value of surgery and/or medical therapy
MRI of hypothalamic hamartoma 0 A. L. SOTOet al.
419
(a)
(W
Fig. 3. A 3-year-old female (Case 4). (a) Sag&al Tl weighted image shows an isodensity mass in the prepontine cistern and hypothalamus (arrowheads). (h) Sag&al T2 weighted image shows a hyperintense mass (arrows) with typical appearanceand origin.
been controversial. Some authors stressed the successful evolution after surgery (12, 14), while others reported good control of PP with medical treatment (3, 4). In our cases, surgery was not successful. Symptoms in two patients were moderately controlled with medical treatment after 3 and 4 years (cases 4 and 5). Re-
peated MR examinations did not show any change in size, shape or signal intensity in the lesion. The differential diagnosis of HH must include gangliogliomas and low grade astrocytomas (6, 12). They may be associated in a rare occasion with PP. The use of Gd-DTPA can be helpful for differential diagnosis.
420
Computerized
Medical
Imaging
and Graphics
November-December1199
1, Volume
15, Number
6
(4 Fig. 3. (continued). (c) Coronal Tl weighted image with post-gadolinium DTF’A. The lesion does not show enhancement (arrows). (d) Sagittal Tl weighted image 4 years after the first MRI. No significant change is fo after 4 years of follow-up (arrowheads).
421
MRI of hypothalamic hamartoma 0 A. L. Sore et al.
In doubtful cases serial MR studies are indicated. Other types of tumors can be excluded because of different signal intensities and clinical presentation. MRI is a well established technique for detection of HH. In medical therapy, MRI is invaluable in follow-up of these patients. The most frequent presentation of HH is a well defined mass in the inferior aspect of the hypothalamus, showing isointensity on Tl weighted images and hyperintensity on T2 weighted images in relation to the gray matter. Further studies are necessary for explanation of the various signal intensities of the lesions. SUMMARY Hypothalamic hamartoma is a relatively rare congenital malformation, associated with clinical presentation of precocious puberty of central type. Five cases with hypothalamic hamartoma were reported with an emphasis on MR appearance. The most common presentation of hypothalamic hamartoma was a small and well defined mass in the inferior aspect of the hypothalamus, showing isointensity on Tl weighted images and hyperintensity on T2 weighted images compared with the gray matter. MRI is invaluable in the diagnosis and follow-up of these patients. REFERENCES 1. Zuniga, O.F.; Tanner, S.M.; Wild, W.O.; Moiser, H.D. Hamartomas of the CNS associated with precocious puberty. Am. J. Dis. Child. 187:127-133; 1983. 2. Shun-Ren, L.; Bryson, M.M.; Globen, R.P.; Yan-Yen, L.; Fitz, CR. Radiologic findings of hamartomas of the tuber cinereum and hypothalamus. Radiology. 127:697-703; 1978. 3. Pescovitz, O.H.; Comite, F.; Hench, K.; et al. The NIH experience with precocious puberty: Diagnostic subgroups and response to short-term luteinizing hormone releasing hormone analogue therapy. J. Pediatr. 59:888-893; 1986. 4. Comite, F.; Pescovitz, O.H.; Rieth, K.G.; et al. Luteinizing hormone-releasing hormone analog. Treatment of boys with hypothalamic hamartoma and true precocious puberty. J. Clin. Endoctinol. Metab. 59:888-893; 1984. 5. Markin, R.S.; Leibrock, LG.; Huseman, C.A.; McComb, R.D. Hypothalamic hamartoma: Report of two cases. Neurosurgery. 16:198-206; 1985.
6. Burton, R.M.; Bull, W.S.; Cronek; Dolan, L.M. Hamartomas of the tuber cinereum. A comparison of MR and CT findings in four cases. AJNR l&497-501; 1989. 7. Hahn, F.J.; Husema, CA; Makos, M.M. The MR appearance of hypothalamic hamartoma. Neuroradiology. 30:6568; 1988. 8. Peterman, S.B.; Steiner, R.E.; Bydder, G.M. Magnetic resonance imaging of intracranial tumors in children and adolescents. AJNR 5:703-709; 1984. 9. Hubbard, A.M. MR imaging of large hypothalamic hamattomas in two infants. AJNR 10:227; 1989. 10. Beningfleld, S.J.; Bonnici, F.; Cremin, B.J. Magnetic resonance imaging of hypothalamic hamartomas. The Br. J. Radiol. 61: 1177-l 180; 1988. 11. Berkovic, S.F.; Anderman, F.; Melanson, D.; Either, R.E.; Feindel, W.; Gloor, P. Hypothalamic hamartomas and ictal laughter: Evolution of a characteristic epileptic syndrome and diagnostic value of magnetic resonance imaging. Ann. Neurol. 23:429-439; 1988. 12. Nishio, S.; Fujiwara, S.; Aiko, Y.; Fukui, M. Hypothalamic hamartoma. Report of two cases. J. Neurosurg. 70640-645; 1989. 13. Riet, K.G.; Comite, F.; Dwyer, A.J.; et al. CT of cerebral abnormalities in precocious puberty. AJNR 8:283-290; 1987. 14. Sato, N.; Yukitaka, Il.; Arita, N.; Mogami, H. Hypothalamic hamartoma: Report of two cases. Neurosurgery. 16:198-206; 1985. About the Author-Dr. ANTONIO LONA Son, worked in clinic radiology for 6 years in the Specialities Hospital of Social Security Mexican Institute. At present, he is studying as a Fellow of Neuroradiology at Kumamoto University. About the Author-Dr. MUTSLIMASA TAKAHASHIis a professor and chairman of the Radiology Department of Kumamoto University School of Medicine. He has made many contibutions in neuroradiology, computed tomography and interventional angiography. Recently, he has extended his field of interest to magnetic resonance imaging, particularly in central nervous system. About the Author-Dr. YASUWKI YAMASHITAspecialized in angiography and abdominal radiology as a staff of the Department of Radiology, Kumamoto University Hospital. His main area of interest is angiography and MRI of the central nervous system and body. About the Author-Dr. YUII SAKAMOTO, after two years of residency, has been engaged mainly with magnetic resonance imaging. His interests include the investigation of the role of Gd-DTPA in the central nervous system. About the Author-Dr. JINTETSU SHINZATO is at Kumamoto University Hospital with an interest in magnetic resonance imaging, especially MR angiography. About
the
Author-Kmmmo
YOSHIZWI
Medical Center, and has an interest in MRI.
is at Minamata General
0895-fd11/91 s3.M) + .oo Copyright 0 1991 PerSamonPress plc
1991
MRI FINDINGS OF HYPOTHALAMIC HAMARTOMA: REPORT OF FIVE CASES AND REVIEW OF THE LITERATURE Antonio Lona Soto, MutsumasaTakahashi”,YasuyukiYamashita, Yuji Sakamoto,JintetsuShinzatoand KazuhiroYoshizumi Department of Radiology,
Kumamoto
University (Received
School of Medicine, 26 December
l-l-l
Honjo, Kumamoto
860, Japan
1990)
Abstract-Hypothalamic hamartuma is a relatively rare congenital malformation, associated with the clinical present@ion of precocious puberty of central type. Five cases with hypothalamic hamartoma are reported here, with an emphasis on MR appearance. The most common presentation of hypothalamic hamartuma was a small and ?wII defined mass in the inferior aspect of the hypothalamus, showing isointensity on Tl weighted images and IQperintensity on T2 weighted images compared with the gray matter. The previous reports with MRI description are reviewed and compared with the present results. Key Words: Brain anomaly, Brain tumor, Hamartoma, Hypothalamus,
INTRODUCTION
TE/excitations); for the 0.5T unit, Tl weighted image with 550/30/2 and T2 weighted images with 1600/ 100/2; and for the 1.5 T unit, Tl weighted image with 600/15-2 and T2 weighted image with 2300/90/l. Three patients underwent a surgery with histological confirmation of HH, whereas two patients received medical treatment. The diagnosis in the last two cases was based on the hormonal test of luteinizing hormone (LH) and stimulation of LH release hormone with confirmation of the lesion by MR studies. Sag&al Tl and T2 weighted images were obtained in most instances and in selected cases coronal or axial planes were added. In case 1 and case 2, a presurgical MR examination was performed. In case 2 and case 3, postsurgical MR studies were available. In two medically treated cases, seven MR examinations were performed with an interval of about 1 year. In these cases we performed follow-up studies for 3 and 4 years. Table 1 summarizes the clinical information of our patients.
Hypothalamic hamartoma (HI-I) is a congenital malformation composed of ectopic neuronal tissue, the origin of the mass being in the inferior aspect of the hypothalamus between the mammillary bodies and pituitary stalk. The mass usually projects into the subarachnoid space by filling the interpeducular, prepontine and/or suprasellar cisterns. The most frequent clinical presentation is precocious puberty (PP) within the first 2 or 3 years of life in about 70 to 90% of the cases (1, 2). Other associated symptoms include laughing seizures, mental retardation and tonic clonic convulsion. We evaluated magnetic resonance (MR) findings in five cases of HH and compared them with the previously reported cases in the literature. METHODS
MR Imaging
AND MATERIALS
The MR findings of five cases with the diagnosis of I-II-I were reviewed. Eleven MR examinations on these cases were performed on three different MR units: a 0.22 T resistive unit (MRT-22A, Toshiba Medical Systems); a 0.5 T superconductive unit (Gyroscan S-5, Philips Medical Systems) and a 1.5 T superconductive unit (Magnetom 15 T, Siemens-Asahi Medical Systems). Pulse sequences used were as follows: for the 0.22 T unit, Tl weighted images with 400-500/40/4 and T2 weighted images with 1660-2000/60-80/2 (tr/
RESULTS HH was recognized by the presence of a small and well defined mass with apparent origin in the inferior aspect of the hypothalamus, projecting into the interpeduncular, suprasellar and/or prepontine cisterns. Tl weighted images showed the mass to be homogeneous and isointense with the gray matter in all patients. The lesion was better delineated on T2 weighted images with homogeneous high signal intensity in four cases. In case 4 (Pig. l), the lesion was isointense with the cortex on T2 weighted images.
*To whom all correspondence should be addressed. 415
416
Computerized Medical Imaging and Graphics
November-December/l99 1, Volume 15, Nwnber 6
(b) Fig. 1. A Syear-old female (Case 5). (a) Sagittal Tl weighted image on admission. A small hypothalamic hamartoma ilsointenseto the cortex is observed (arrowheads). (b) Sagittal Tl weighted images at 3 years after first MRI.
Case 2 showed the biggest lesion (3.8 X 2.7 cm) in the sag&al section with slight compression of the pons. The mass effect diminished after the surgery (Fig. 2). The smallest lesion was 1.0 X 1.2 cm in the sag&al plane in case 3. The image quality with the 1.5 T unit was superior to that of 0.5 T and 0.22 T units. How-
ever, the detectability and demonstration of the lesion were not significantly different. In serial studies with three different units, the lesion did not show any change in signal intensity. In these two medically treated cases, the mass did not show any change in size, shape or signal intensity in the period of 3 and 4 years (Figs. 1
417
MRI of hypothalamic hamartoma . A. L. So’ro et al.
Fig. 1. (continued)
(c) Sagittal T2 weighted images at 3 years after fmt MRI. The lesion shows same size and signal intensity after 3 years of follow-up (arrowheads).
and 3). In addition, in case 5 Gd-DTPA was administered and the lesion did not show contrast enhancement (Fig. 3c). The clinical course of the three surgically treated patients did not show significant improvement after surgery. The symptoms of PP were moderately controlled in medically treated cases. DISCUSSION HH is recognized as the most common lesion associated with PP of central type (2, 3). The mechanism of PP has not been well established. Two theories have
been proposed, mechanical compression over the hypothalamus with loss of the inhibitory effects on the release of gonadotropin (4) and direct neuronal co~ection with production of the hormones by the lesion. The value of MRI in demonstration of HH has been described by other authors (5-12). We found 18 cases of HH in the literature with MRI description. Ten of these cases showed isointensity on Tl weighted images and hyperintensity on T2 weighted images in relation to the cortex (5-8). This finding was consistent with our observations in four of five cases in our series. BeningEeld et al. (9) and Hubbard et al. (10) described four cases with isointensity on both Tl and T2 weight-
Table 1. Diagnosis, clinical manifestations CaSe No.
Sex
Age of initial diagnosis
1
M
2
M
3
and MRI findings. MRI Intensity
Clinical presentation
MRI examination
TlWI
T2w.I
Treatment
2 years
PP, mental retardation
Pre-surgery
Is0
High
Sw9ry
2 years
PP, laughing seizures, tonicclonic convulsion
Pre- and Postswery
Is0
High
-Qwry
M
1 year
PP
Post-surgery
Is0
High
4
F
3 years
9years
PP
Follow-up 4 years
IS0
5
F
1 year
5 years
PP
Follow-up 3 years
IS0
w& Is0
swery Medical
PP = Precocious puberty
Resent age
retardation
Medical
418
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Medical
Imaging
and Graphics
November-December/l991,
Volume
15, Number
6
(4
Fig. 2. A 2-year-old male (Case 2). (a) Sag&al T2 weighted image before surgery. There is a hyperintense signal lesion in the suprasellarcistern, prepontine cistern and hypothalamus (arrowheads). Note the slight compression of the pons. (b) Sagittal Tl weighted image (postsurgery). The hamartoma is isointense and homogeneous, while the masseffect decreased(arrowheads).
ed images. In our series one case showed such findhi! IS. Other authors (11, 12) reported the mass to be hylFrtense on Tl and T2 weighted images. However, we did not have such a finding in our series. We did no1 : find any good explanation for such a discrepancy. Ho lwever, the histological description in surgical cases
(5, 12, 14) revealed different amount and type :s of neuronal and glial cells. On the other hand, the amiount of myelin may be different in neuronal cells. These tW0 findings could explain the different signal intenr rities seen in these patients. The value of surgery and/or medical therapy
MRI of hypothalamic hamartoma 0 A. L. SOTOet al.
419
(a)
(W
Fig. 3. A 3-year-old female (Case 4). (a) Sag&al Tl weighted image shows an isodensity mass in the prepontine cistern and hypothalamus (arrowheads). (h) Sag&al T2 weighted image shows a hyperintense mass (arrows) with typical appearanceand origin.
been controversial. Some authors stressed the successful evolution after surgery (12, 14), while others reported good control of PP with medical treatment (3, 4). In our cases, surgery was not successful. Symptoms in two patients were moderately controlled with medical treatment after 3 and 4 years (cases 4 and 5). Re-
peated MR examinations did not show any change in size, shape or signal intensity in the lesion. The differential diagnosis of HH must include gangliogliomas and low grade astrocytomas (6, 12). They may be associated in a rare occasion with PP. The use of Gd-DTPA can be helpful for differential diagnosis.
420
Computerized
Medical
Imaging
and Graphics
November-December1199
1, Volume
15, Number
6
(4 Fig. 3. (continued). (c) Coronal Tl weighted image with post-gadolinium DTF’A. The lesion does not show enhancement (arrows). (d) Sagittal Tl weighted image 4 years after the first MRI. No significant change is fo after 4 years of follow-up (arrowheads).
421
MRI of hypothalamic hamartoma 0 A. L. Sore et al.
In doubtful cases serial MR studies are indicated. Other types of tumors can be excluded because of different signal intensities and clinical presentation. MRI is a well established technique for detection of HH. In medical therapy, MRI is invaluable in follow-up of these patients. The most frequent presentation of HH is a well defined mass in the inferior aspect of the hypothalamus, showing isointensity on Tl weighted images and hyperintensity on T2 weighted images in relation to the gray matter. Further studies are necessary for explanation of the various signal intensities of the lesions. SUMMARY Hypothalamic hamartoma is a relatively rare congenital malformation, associated with clinical presentation of precocious puberty of central type. Five cases with hypothalamic hamartoma were reported with an emphasis on MR appearance. The most common presentation of hypothalamic hamartoma was a small and well defined mass in the inferior aspect of the hypothalamus, showing isointensity on Tl weighted images and hyperintensity on T2 weighted images compared with the gray matter. MRI is invaluable in the diagnosis and follow-up of these patients. REFERENCES 1. Zuniga, O.F.; Tanner, S.M.; Wild, W.O.; Moiser, H.D. Hamartomas of the CNS associated with precocious puberty. Am. J. Dis. Child. 187:127-133; 1983. 2. Shun-Ren, L.; Bryson, M.M.; Globen, R.P.; Yan-Yen, L.; Fitz, CR. Radiologic findings of hamartomas of the tuber cinereum and hypothalamus. Radiology. 127:697-703; 1978. 3. Pescovitz, O.H.; Comite, F.; Hench, K.; et al. The NIH experience with precocious puberty: Diagnostic subgroups and response to short-term luteinizing hormone releasing hormone analogue therapy. J. Pediatr. 59:888-893; 1986. 4. Comite, F.; Pescovitz, O.H.; Rieth, K.G.; et al. Luteinizing hormone-releasing hormone analog. Treatment of boys with hypothalamic hamartoma and true precocious puberty. J. Clin. Endoctinol. Metab. 59:888-893; 1984. 5. Markin, R.S.; Leibrock, LG.; Huseman, C.A.; McComb, R.D. Hypothalamic hamartoma: Report of two cases. Neurosurgery. 16:198-206; 1985.
6. Burton, R.M.; Bull, W.S.; Cronek; Dolan, L.M. Hamartomas of the tuber cinereum. A comparison of MR and CT findings in four cases. AJNR l&497-501; 1989. 7. Hahn, F.J.; Husema, CA; Makos, M.M. The MR appearance of hypothalamic hamartoma. Neuroradiology. 30:6568; 1988. 8. Peterman, S.B.; Steiner, R.E.; Bydder, G.M. Magnetic resonance imaging of intracranial tumors in children and adolescents. AJNR 5:703-709; 1984. 9. Hubbard, A.M. MR imaging of large hypothalamic hamattomas in two infants. AJNR 10:227; 1989. 10. Beningfleld, S.J.; Bonnici, F.; Cremin, B.J. Magnetic resonance imaging of hypothalamic hamartomas. The Br. J. Radiol. 61: 1177-l 180; 1988. 11. Berkovic, S.F.; Anderman, F.; Melanson, D.; Either, R.E.; Feindel, W.; Gloor, P. Hypothalamic hamartomas and ictal laughter: Evolution of a characteristic epileptic syndrome and diagnostic value of magnetic resonance imaging. Ann. Neurol. 23:429-439; 1988. 12. Nishio, S.; Fujiwara, S.; Aiko, Y.; Fukui, M. Hypothalamic hamartoma. Report of two cases. J. Neurosurg. 70640-645; 1989. 13. Riet, K.G.; Comite, F.; Dwyer, A.J.; et al. CT of cerebral abnormalities in precocious puberty. AJNR 8:283-290; 1987. 14. Sato, N.; Yukitaka, Il.; Arita, N.; Mogami, H. Hypothalamic hamartoma: Report of two cases. Neurosurgery. 16:198-206; 1985. About the Author-Dr. ANTONIO LONA Son, worked in clinic radiology for 6 years in the Specialities Hospital of Social Security Mexican Institute. At present, he is studying as a Fellow of Neuroradiology at Kumamoto University. About the Author-Dr. MUTSLIMASA TAKAHASHIis a professor and chairman of the Radiology Department of Kumamoto University School of Medicine. He has made many contibutions in neuroradiology, computed tomography and interventional angiography. Recently, he has extended his field of interest to magnetic resonance imaging, particularly in central nervous system. About the Author-Dr. YASUWKI YAMASHITAspecialized in angiography and abdominal radiology as a staff of the Department of Radiology, Kumamoto University Hospital. His main area of interest is angiography and MRI of the central nervous system and body. About the Author-Dr. YUII SAKAMOTO, after two years of residency, has been engaged mainly with magnetic resonance imaging. His interests include the investigation of the role of Gd-DTPA in the central nervous system. About the Author-Dr. JINTETSU SHINZATO is at Kumamoto University Hospital with an interest in magnetic resonance imaging, especially MR angiography. About
the
Author-Kmmmo
YOSHIZWI
Medical Center, and has an interest in MRI.
is at Minamata General
