Relationships between neuroradiological and clinical features in apparently idiopathic hypopituitarism

Abstract

In this study, perinatal history, postnatal auxological and clinical evolution and endocrine features were retrospectively evaluated in 49 children, adolescents and young adults with apparently idiopathic hypopituitarism. They were divided into two groups according to magnetic resonance images: 32 patients with isolated pituitary hypoplasia (group A) and 17 with pituitary stalk interruption syndrome (group B). The aim of the study was to assess whether these neuroradiological pictures are associated with specific endocrine and clinical patterns. No significant difference in terms of gestational age, intrauterine growth and rates of adverse perinatal events was found between the two groups. Clinical signs documenting the existence of pituitary dysfunction in utero or shortly after birth were either slightly (micropenis, cryptorchidism, cholestatic jaundice) or significantly (hypoglycemia) more frequent in patients in group B. Although diagnosis of hypopituitarism was made significantly earlier in patients in group B, height deficiency at diagnosis was similar in both groups. Endocrine investigations revealed a more severe and widespread impairment of pituitary function among those in group B. The main conclusion is that the postnatal clinical course is more severe when growth hormone deficiency is associated with pituitary stalk interruption syndrome than when the pituitary is only reduced in height, probably because of the more severe and widespread impairment of pituitary function in the former cases.

Investigação neurorradiológica de pacientes com deficiência idiopática de hormônio do crescimento

“…[1][2][3][4][5] In certain situations, as is observed with partial hormone deficiencies, GHD diagnosis may be problematic and require laboratory investigation that is expensive, complex, and often difficult to interpret. Images obtained by MRI offer greater accuracy compared with CT, and MRI is therefore considered a better method than CT for investigating patients with GHD.…”

“…5 Recent studies of children with reduced height known to have GHD, resulting from causes other than tumors, demonstrate that the principal abnormality found with MRI is hypoplastic anterior pituitary associated with an interrupted stalk and ectopic posterior pituitary, [1][2][3][4]6 this last being rarely seen with CT. 5 It is, therefore, consensus that when investigating restricted stature, the observation of a hypoplastic anterior pituitary associated with an ectopic posterior pituitary on MRI can be a strong indication of GHD. 1,3,4,11,12 Among our patients, 54% presented abnormalities on MRI and, of the abnormalities observed, a hypoplastic anterior pituitary associated with an ectopic posterior pituitary was the most common finding, being present in 70% of our cases. The results found by this study are comparable with published data that also records a large number of morphological anomalies in MRI of the hypothalamic-pituitary area of patients with GHD, among which an ectopic posterior pituitary was common.…”

“…In such cases, images obtained by CT and/or MRI facilitate the detection of anatomic abnormalities, which, in the majority of cases are indicators of permanent growth hormone deficiency. [1][2][3][4][5] Magnetic resonance imaging is a non-invasive method which offers greater sensitivity than CT for identification of abnormalities in the hypothalamic-pituitary region 5 and is considered useful, not just in diagnosis, but also when making treatment decisions for patients with GHD.…”

“…Previously the majority of GHD cases were diagnosed as idiopathic, but with the advent of MRI it has been possible to observe in such patients a characteristic structural anomaly described as the pituitary stalk interruption syndrome, 3,4,6,7 which is more difficult to identify with CT. 5 A number of different publications 1,3,4,6,8 have tried to correlate the morphological alterations seen with MRI with isolated growth hormone deficiency (IGHD) or as multiple anterior pituitary deficiencies (MPHD). Studies have shown that children with MPHD exhibit a higher frequency of abnormalities on MRI when compared with those that have IGHD.…”

“…3,9 Pituitary stalk interruption syndrome has been associated with MPHD, and therefore with greater severity of hypopituitarism, while an intact stalk has been observed with greater frequency in patients with IGHD. 1,4,8 This study is based on the hypothesis that structural abnormalities in the hypothalamic-pituitary region would be common in our group of patients with GHD, and that abnormal MRI findings could be an indicator of hypopituitarism severity. As ectopic posterior pituitary is frequently observed in patients with GH deficiency, 4,6,7 we postulated that if this finding is present in our short stature patients it would allow us to diagnose doubtful cases, thus avoiding unnecessary exhaustive laboratory investigation.…”