J. Endocrinol. Invest. 15: 283-287, 1992
Idiopathic anterior hypopituitarism: magnetic resonance imaging and clinical correlation G. ProtO*, A. Mazzolini*, F. Grimaldi*, F. Bertolissi*, R.S. Pozzi-Mucelli**, and S. Magnaldi** *Servizio di Endocrinologia, Ospedale Generale di Udine, 33100 Udine, and ** Istituto di Radiologia, Universita di Trieste, 34194 Trieste, Italy ABSTRACT. We describe the anatomical abnormalities in the hypothalamic-pituitary region revealed by magnetic resonance imaging (MRI) in 10 patients, 8 men and 2 women, affected by idiopathic anterior hypopituitarism (IAH).ln all cases contiguous sagittal and coronal T-1 weighted images were obtained. In 9 patients the high-intensi-
ty posterior lobe was missing, in almost all patients the pituitary stalk was thin and/or transected, and in 8 a bright T -1 nodule was detected at the infundibular apex, near the tuber cinereum, in the median eminence, None had diabetes insipidus. MRI proves to be very useful in understanding the etiopathogenesis of IAH.
INTRODUCTION
No patient reported a personal history of intrauterine insults, perinatal hypoglycemia and trauma or hyperbilirubinemia. No patient had autoimmune diseases. Basal determinations of each anterior pituitary hormone were perfomed. Provocative endocrine testing was employed to confirm the diagnosis: GH and cortisol were assayed by insulin induced hypoglycemia (0.1 U/Kg, in bolus); LH-RH (100 I1g, iv) and TRH (200 I1g iv) tests were also employed to evaluate the secretory reserve of the pituitary hormone. Results of the endocrinologic evaluation are summarized in Table
The pituitary gland and the infundibulum are clearly demonstrated with magnetic resonance imaging (MRI), thus allowing us to examine the anatomy of the sellar and perisellar region in vivo. MRI usefulness for showing abnormalities in the hypothalamic-pituitary region is reported in several articles, mostly concerning pituitary dwarfs (1-5) while a few of them deal with patients affected by idiopathic anterior hypopituitarism (IAH) (6-9). In this article we report the MRI findings observed in 10 patients with IAH.
2.
MATERIALS AND METHODS
Serum concentration of TSH, PRL, LH, FSH, cortisol and GH were measured by RIA methods. The posterior pituitary gland secretion was evaluated in all patients: none had diabetes insipidus and even anosmia was excluded. IAH may not be diagnosed for long periods, in fact our patients' age at diagnosis varied from 9 to 44 years. All of them had an initial and predominant deficit of the gonadotropin hormones. The two females presented primary amenorrhea, underdeveloped sexual primary and secondary characters, infantilism of the external and internal genitalia. The three male patients affected by IAH since before puberty (case nos. 1, 7, 8) had received GH replacement therapy; they had not (case nos. 7, 8) or had only mild (case no. 1) eunuchoid features, while the other males had a severe eunuchoid appearance. At the time of MRI study all patients were receiving
We investigated 10 patients, 8 males and 2 females, mean age 44 years (age range 26-59 years), with IAH. Since IAH was not diagnosed in the first years of life it is not possible to establish if the insult leading to the hypopituitary state was congenital (i.e. occurred in utero) or acquired at a later age. The current clinical characteristics (heights, weights, Tanner stages of sexual development, and bone ages together with congenital anomalies and associated diseases) are summarized in Table 1.
Key-words: Idiopathic anterior hypopituitarism. magnetic resonance imagIng. empty sella, pituitary size and stalk, ectopic posterior lobe. Correspondence' Giovanni Proto, MD, Servizio di Endocrrnologla, Ospedale Generale di Udine, Piazza S Maria della Misericordia, 33100 Udine, Italy Received October 17.1991: accepted February 20,1992.
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Table 1 - Clinical data of the patients. Patient no.
Sex
Age (yr)
Age at diagnosis (yr)
Height (cm)
Weight (Kg)
M
29
9
100
15
F
59
43
139
37
2
Pubertal stages '
Bone age (yr)
Congenital anomalies
Associated diseases
6
3
F
41
28
152
57.1
4
M
58
38
162
59.6
5
M
50
36
166
55
6
M
59
44
172
117
7
M
27
13
126.5
26.9
10
8
M
38
13
130
33
6
9
M
50
40
163
69
10
M
26
18
160
66
aortectasia genu valgum
agenesia of left lobus of the thyroid gland
12
short fourth metacarpal
'Tanner stages of sexual devolopment
appropriate replacement therapy, prednisone (5 7.5 mg/d), or cortisone acetate (12.5 - 25 mg/d), and L-tiroxine (100-150 Ilg/d) orally; androgen as long acting intramuscular preparation, 250 mg every 3-4 weeks, and estrogen. MR images were obtained by a 1.5 tesla super-
conducting unit (Philips Gyroscan S 15). Contiguous sagittal and coronal T1 - weighted images were taken in all patients with 3mm thickness. Patients were examined using Spin Echo T1 weighted sequences with a TR=460 msec, TE=20 msec and 4 averages. Fast Field Echo sequence were al-
Table 2 - Endocrinologic evaluation. Patient LH no. (mUl/ml) basal peak '
0.6
1.2
FSH T (ng/ml) (mUl/ml) basal peak ' OA
2
E2 (pg/ml)
0.8
PRL (ng/ml) basal peak2
10
20
GH
TSH
(ng/ml) basal peak 3
0.9
1.5
(~UI/ml)
basal peak2
0.2
1.3
T4 T3 ACTH CORTISOL (ng/ml) (ng/ml) (pg/ml) (ng/ml)
32
0.8
47
2
0.5
1.6
0.8
1.2
18
16
35
0.3
0.5
31
0.7
48
3
1.2
1A
OA
0.6
20
15
30
0.8
2.1
21
0.7
25
4
0.6
1.2
0.2
1.1
1.1
18
32
0.9
1.3
34
0.9
5
0.6
1.1
0.5
1.9
0.9
16
22.6
0.2
0.2
40
0.8
6
0.6
0.8
OA
0.8
0.8
18
28
OA
0.8
38
0.8
10
46
7
0.8
1.2
0.8
1.2
0.7
20
38
0.7
1.5
0.2
0.2
35
0.9
8
30
8
0.7
1.8
0.4
1.6
0.8
5.8
37.5
0.1
0.1
0.2
0.6
34
0.8
10
35
34.5 28.2
0.8
1.5
M
2-14