
==== Front
Ann Med Surg (Lond)
Ann Med Surg (Lond)
MS9
Annals of Medicine and Surgery
2049-0801
Lippincott Williams & Wilkins Hagerstown, MD

AMSU-D-24-00196
10.1097/MS9.0000000000002067
00080
3
Case Reports
Pituitary stalk interruption syndrome: a case report and literature review
Ali Alqarni Abdullah aabdullahasalmohsen@gmail.com

Abdalla Khalid Mohamed ddr.khalidmabdalla@gmail.com

Alqarni Mohammed A. S. c
Alfaifi Jaber A. bjalfaifi@ub.edu.sa

Osman Hisham G. A. dr.Hisham10888@gmail.com
d
Al Alhindi Bandar S. aaalhendi@ub.edu.sa

a Department of Medicine, College of Medicine, University of Bisha
b Department of Child Health, College of Medicine, University of Bisha
c Hospital Director of Maternity and Children’s Hospital
d King Abdullah Hospital, Bisha, Kingdom of Saudi Arabia
* Corresponding author. Address: E-mail: abdullahasalmohsen@gmail.com (A.A. Alqarni).
9 2024
17 4 2024
86 9 54865488
23 1 2024
31 3 2024
Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0/

Background:

Pituitary stalk interruption syndrome is a rare congenital anomaly of the pituitary gland characterized by growth hormones deficiency (with or without other pituitary hormone deficiencies) along with radiological features of a thin or interrupted pituitary stalk, an ectopic or absent posterior pituitary, or a hypoplastic or absent anterior pituitary.

Case presentation:

A 10-year-old baby boy came with short stature. The laboratory investigations were done and showed low growth hormones and low thyroid-stimulating hormone. MRI showed an ectopic posterior pituitary, a small hypoplastic anterior pituitary, and an absent pituitary stalk.

Conclusion:

Pituitary stalk interruption syndrome is a very rare entity. MRI is used to diagnose it. Early detection of this syndrome improve the patient symptoms especially before puberty.

Keywords:

growth hormone
magnetic resonance imaging
pituitary stalk interruption syndrome
OPEN-ACCESSTRUE
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pmcIntroduction

Highlights

Pituitary stalk interruption syndrome is a very rare entity.

Incidence rate of 0.5/1 000 000 births and with male predominance.

MRI is used to diagnose it.

Early detection of this syndrome improve the patient symptoms especially before puberty.

Pituitary stalk interruption syndrome (PSIS) is a rare entity with an estimated incidence rate of 0.5/1 000 000 births and with male predominance1,2. The first-ever reported case was by Fujisawa et al.3 in 1987 after surgical resection of the pituitary stalk in a patient with idiopathic pituitary dwarfism. While the etiology and pathophysiology of PSIS are not fully known, a strong relationship with birth trauma resulting in prenatal pituitary injury, including breech or footling presentation, dystocia, and cesarean delivery, has been observed4,5. PSIS is also thought to be caused by mutations in pituitary embryogenesis genes (PROP1, LHX3, HEXSX1, PROKR2, and GPR161)6. This syndrome is a congenital anomaly of the pituitary gland characterized by growth hormone (GH) deficiency (with or without other pituitary hormone deficiencies) along with radiological features of a thin or interrupted pituitary stalk, an ectopic or absent posterior pituitary, or a hypoplastic or absent anterior pituitary3,7. We report the example of a young boy who presented with short stature and was eventually diagnosed with PSIS. To the best of our knowledge, this is the first-ever reported case of PSIS from Saudi Arabia.

Case presentation

A 10-year-old boy was brought in general pediatric clinic due to concerns about his notably short stature compared to peers of his age. Upon conducting an initial assessment, a series of laboratory tests were performed to evaluate his hormonal levels, given the suspected endocrine nature of his growth delay.

Laboratory findings

The laboratory investigations revealed significantly reduced levels of GH and thyroid-stimulating hormone (TSH), which are critical for normal growth and metabolism. Specifically, the Somatomedin-C (IGF-1) level was markedly low at 8 ng/ml, with the reference range being 85–249 ng/ml. This finding is consistent with GH deficiency, which can contribute to the patient’s short stature.

In addition to hormonal assays, MRI of the pituitary gland was conducted to explore the anatomical basis of the observed hormonal deficiencies. The MRI findings were notable for an ectopic posterior pituitary gland, a significantly underdeveloped anterior pituitary gland, and the complete absence of the pituitary stalk (Figs 1 and 2).

Figure 1 (A, B) Coronal and sagittal T1 precontrast shows ectopic posterior pituitary arrow, hypoplastic anterior pituitary curved orange arrow, and absent pituitary stalk open white arrow.

Figure 2 (A, B) Coronal and sagittal T1 postcontrast shows ectopic posterior pituitary arrow, hypoplastic anterior pituitary curved orange arrow, and absent pituitary stalk open white arrow.

These radiological findings, in conjunction with the laboratory results, led to the diagnosis of PSIS.

The combination of the patient’s clinical presentation, the hormonal assay results, and the MRI findings provided a clear picture, confirming the diagnosis of PSIS. This case highlights the importance of a thorough diagnostic workup, including both laboratory and imaging studies, in the evaluation of pediatric patients presenting with growth retardation.

Following the diagnosis, a multidisciplinary approach to management was initiated, involving pediatric endocrinology for hormonal replacement therapy and close monitoring of the patient’s growth and development. This case underscores the critical role of early detection and intervention in managing rare endocrinological disorders such as PSIS, particularly in pediatric patients where growth and development are significantly impacted (Figs 1 and 2).

Discussion

Fujisawa et al.3 first reported PSIS in 1987. PSIS has a male predominance, with a male-female sex ratio ranging from 2.3 to 6.9:1, indicating X-linked inheritance. The mean age of diagnosis is 9.4–11.6 years, with neonatal distress and breech delivery not affecting the presentation age10. The exact prevalence of this syndrome remains unknown. Less than 1000 cases were reported in the literature until 201011. Its prevalence as a cause of GH deficiency is around 4%4. The age at diagnosis differs according to the severity of the hormone deficiency. When PSIS presents at birth, hypoglycemia, and failure to thrive are the most common symptoms. Growth retardation is usually the presenting complaint in childhood, whereas delayed puberty is usually the chief complaint when it manifests in adolescence and early adulthood6,7. Our case was a 10-year-old boy who presented to us with short stature and was eventually diagnosed with PSIS.

The pathogenesis is unknown, but perinatal anoxia and breech presentation at birth may cause pituitary stalk injury9. The relationship with undescended testes and micropenis and the occurrence of syndromal forms caused by genetic abnormalities in HESX1, LHX4, and SOX3 point to a prenatal origin8,12. El Chehadeh-Djebbar et al. reported the first case of PSIS in association with 17q21.31 microdeletion in 20111. Approximately 20–50% of the patients have some associated congenital abnormality, mostly midline structural, for example, in the cleft lip and palate, an absent diaphragm, and axial skeletal anomalies, with the hypoplastic optic nerve being the most common, all of which suggest an association with improper embryonal migration of neural crest cells13.

These patients have multiple hormonal deficiencies. Growth hormone deficiency is the most frequently existing deficiency and reaches 100% of all patients. Interestingly, considerable heterogeneity in height has been reported. Few children maintain normal linear growth despite abnormal GH secretion4. Gonadotropin deficiency [luteinizing hormone (LH), follicle-stimulating hormone (FSH)] is frequently associated with other deficiencies. Adrenocorticotropic hormone (ACTH) deficiency can cause neonatal cholestasis and recurrent hyponatremia. Stimulation test for ACTH and cortisol measurement have shown their levels to be significantly lower in patients with PSIS4. Prolactin levels have shown a considerable degree of heterogeneity. It can be deficient, or hyperprolactinemia can be observed in 17% to one-third of patients. It varies depending on the severity of dopaminergic pathway disconnection4. Owing to different embryonic origins of the anterior and posterior pituitary, only a few patients have complained of central diabetes insipidus. In the neonatal period, features indicative of hypopituitarism, hypotonia, secondary adrenal deficiency with hypotension, prolonged cholestatic icterus, and repeated episodes of hypoglycemia are found in 33% of PSIS patients4. TSH deficiency may also be seen, but measurement may be within the normal limits in most patients with central hypothyroidism. Cases have been described with isolated sparing of TSH secretion with a deficiency of the remaining anterior pituitary hormones4. Our case had low GH and TSH levels.

PSIS MRI findings include hypoplasia or aplasia of the anterior pituitary, absence of the hyper-intense posterior lobe within the sella turcica and its presence as a hyper-intense nodule at the level of the median eminence or the pituitary stalk, and absence or thinned out pituitary stalk8,10,14. However, the presentation of this illness on MRI varies. The height of the anterior pituitary (from absence to normal), the appearance of the posterior pituitary lobe (ectopic at the base of the hypothalamus or along the pituitary stalk, absent, or normal), and the shape of the pituitary stalk (interrupted, thin, nonexistent, or normal) are all examples of these differences. An ectopic posterior pituitary can be the only abnormality10. Regarding our case, the MRI showed an ectopic posterior pituitary, a small hypoplastic anterior pituitary, and an absent pituitary stalk.

Conclusion

PSIS is a rare condition. However, radiologists should remember this syndrome for neonatal patients with hypoglycemia, seizures, jaundice, cryptorchidism, hypothyroidism, and children with growth retardation due to pituitary hormone deficits.

Ethical approval

Yes ethical approval was done at Research and Innovation Centre, King Abdullah Hospital, Bisha.

Consent

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Source of funding

None.

Author contribution

A.A.A. and K.M.A.I.: writing and diagnosis; M.A.S. and H.G.A.O.: diagnosis of the case; B.S.A.A. and J.A.A: writing the case.

Conflicts of interest disclosure

The authors declare no conflict of interest.

Research registration unique identifying number (UIN)

Name of the registry.

Guarantor

Abdullah AlQarni.

Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.
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