69  Pituitary Gland Disorders

69.1 Introduction

The pituitary gland, often called the “master gland”, plays a central role in the regulation of growth, metabolism, reproduction, and stress response. Its hormones influence nearly every endocrine organ, including the thyroid, adrenal glands, and gonads. Disorders of the pituitary gland, therefore, have wide-ranging systemic effects and are of great importance in paediatric practice.

In Ghana, pituitary disorders in children are likely underdiagnosed due to limited access to hormonal assays and imaging facilities. Many children with growth failure or delayed puberty are labelled as “constitutional” cases without proper evaluation. Moreover, paediatric endocrinology services are still emerging, and awareness among frontline health workers remains low. Recognising pituitary disorders early can prevent serious complications, including permanent growth failure, adrenal crisis, or infertility.

This chapter provides an overview of pituitary anatomy and physiology, discusses common and important pituitary disorders in childhood, and outlines their diagnosis and management, with emphasis on practical approaches in resource-limited settings.

69.2 Anatomy and Physiology of the Pituitary Gland

The pituitary gland is a small, oval-shaped endocrine organ located at the base of the brain in the sella turcica, just below the hypothalamus. It is connected to the hypothalamus by the pituitary stalk (infundibulum) and is divided into two main parts:

  • Anterior pituitary (adenohypophysis) — produces six key hormones:
    • Growth hormone (GH)
    • Adrenocorticotropic hormone (ACTH)
    • Thyroid-stimulating hormone (TSH)
    • Luteinizing hormone (LH)
    • Follicle-stimulating hormone (FSH)
    • Prolactin (PRL)
  • Posterior pituitary (neurohypophysis) — stores and releases two hypothalamic hormones:
    • Antidiuretic hormone (ADH, also called vasopressin)
    • Oxytocin

The hypothalamus regulates pituitary function through releasing and inhibiting hormones. These hormones are secreted into the hypophyseal portal circulation, linking the hypothalamus and pituitary into an integrated hypothalamic–pituitary axis.

69.3 Classification of Pituitary Disorders

Pituitary gland disorders in children can be broadly classified as follows:

  1. Hypopituitarism — deficiency of one or more pituitary hormones
  2. Hyperpituitarism — excess secretion of one or more hormones
  3. Posterior pituitary disorders — abnormalities of ADH secretion (diabetes insipidus or SIADH)
  4. Structural lesions — pituitary adenomas, cysts, craniopharyngiomas, or infiltrative diseases

Each disorder manifests differently, depending on which hormones are affected and at what stage of development the dysfunction occurs.

69.4 Hypopituitarism

69.4.1 Definition

Hypopituitarism refers to partial or complete deficiency of anterior and/or posterior pituitary hormones. It may be congenital (present at birth) or acquired (occurring later due to injury, tumour, or infection).

69.4.2 Causes

Congenital causes include: - Midline developmental defects (septo-optic dysplasia, holoprosencephaly)

  • Genetic mutations affecting pituitary transcription factors (PROP1, POU1F1)
  • Perinatal asphyxia or trauma
  • Structural anomalies of the pituitary or hypothalamus on MRI

Acquired causes include: - Central nervous system tumours (especially craniopharyngioma)

  • Head trauma or irradiation
  • Infections such as meningitis or tuberculosis
  • Infiltrative diseases (e.g., Langerhans cell histiocytosis)

In Ghana, birth asphyxia, CNS infections, and head trauma are likely the commonest causes of acquired hypopituitarism.

69.4.3 Clinical Features

The clinical presentation depends on the number and severity of hormone deficiencies:

  • Growth hormone deficiency (GHD): short stature, increased fat mass, immature face, delayed dentition
  • TSH deficiency: secondary hypothyroidism (fatigue, poor growth, cold intolerance)
  • ACTH deficiency: adrenal insufficiency (hypoglycaemia, hypotension, fatigue)
  • Gonadotropin deficiency: delayed or absent puberty
  • Prolactin deficiency: failure of lactation in post-partum females (less relevant in children)

Infants with panhypopituitarism may present with hypoglycaemia, prolonged jaundice, micropenis, and poor feeding. Without recognition, mortality may occur due to adrenal crisis.

69.4.4 Diagnosis

Diagnosis requires both biochemical assessment and neuroimaging.

  • Basal hormone levels: TSH, free T₄, cortisol, GH, IGF-1, LH/FSH, prolactin
  • Dynamic testing (e.g., insulin tolerance test, ACTH stimulation test) — when available
  • MRI of the brain to identify structural anomalies or tumours

In Ghana, access to dynamic testing may be limited to teaching hospitals such as KATH or KBTH. Clinicians in regional hospitals may rely on clinical findings, basic thyroid function tests, and growth parameters to guide management.

69.4.5 Management

Treatment focuses on hormone replacement and management of underlying causes.

  • Hydrocortisone for ACTH deficiency (8–10 mg/m²/day in divided doses)
  • Levothyroxine for TSH deficiency
  • Recombinant GH for GHD (0.025–0.035 mg/kg/day subcutaneously)
  • Sex steroids for pubertal induction when older

In resource-limited settings, the high cost of GH therapy limits access, and prioritization is often necessary. Multidisciplinary care involving paediatric endocrinologists, dietitians, and psychologists yields the best outcomes.

69.5 Growth Hormone Deficiency (GHD)

GHD is the most common isolated pituitary hormone deficiency in children. It may be idiopathic, genetic, or secondary to structural lesions.

69.5.1 Clinical Features

Children typically present with:

  • Short stature with normal body proportions
  • Delayed skeletal maturation
  • Chubby face and truncal obesity
  • Delayed dentition and puberty

In Ghana, such children are often brought late for evaluation, sometimes after unsuccessful use of herbal remedies or growth tonics.

69.5.2 Diagnosis

  • Low serum IGF-1 and IGFBP-3 levels
  • GH stimulation tests (e.g., clonidine, insulin) to confirm deficiency
  • MRI to assess pituitary morphology

69.5.3 Treatment

Daily subcutaneous recombinant GH therapy leads to excellent catch-up growth if started early. Monitoring of growth velocity, pubertal development, and thyroid function is essential.

Where GH therapy is unavailable, nutritional optimisation, thyroid screening, and regular monitoring are still beneficial. Psychosocial support for affected children is also essential.

69.6 Hyperpituitarism

69.6.1 Definition and Causes

Hyperpituitarism refers to excessive secretion of one or more pituitary hormones, often due to pituitary adenomas. In children, these are usually benign but can cause significant morbidity by compressing adjacent structures or overproducing hormones.

Common examples include:

  1. GH-secreting adenoma: gigantism
  2. Prolactin-secreting adenoma (prolactinoma): galactorrhoea, delayed puberty
  3. ACTH-secreting adenoma: Cushing’s disease

69.6.2 Growth Hormone Excess (Gigantism)

69.6.2.1 Clinical Features

  • Rapid linear growth with tall stature
  • Coarse facial features, broad hands and feet
  • Headaches and visual disturbances due to tumour mass
  • Glucose intolerance or diabetes mellitus

69.6.3 Diagnosis

  • Elevated IGF-1 levels
  • Failure of GH suppression after oral glucose load
  • Pituitary MRI showing macroadenoma

69.6.3.1 Management

  • Trans-sphenoidal surgery (definitive)
  • Somatostatin analogues (octreotide) if surgery fails or is not available
  • Radiation therapy for residual tumour

In Ghana, collaboration between neurosurgery and endocrinologyis essential but often limited to tertiary centres.

69.6.4 Prolactinoma

Prolactinomas cause hyperprolactinaemia, leading to delayed puberty, amenorrhoea, or galactorrhoea.

  • Diagnosis: elevated serum prolactin, pituitary MRI
  • Treatment: dopamine agonists (cabergoline or bromocriptine)
  • Surgery if medical therapy fails

69.7 Posterior Pituitary Disorders

The posterior pituitary releases antidiuretic hormone (ADH), which regulates water balance. Two major disorders may occur:

69.7.1 Diabetes Insipidus (DI)

69.7.1.1 Pathophysiology

Caused by deficiency (central DI) or resistance (nephrogenic DI) to ADH. Central DI may result from:

  • Head trauma
  • Craniopharyngioma or other tumours
  • Post-surgical damage
  • CNS infections such as meningitis or tuberculosis

69.7.1.2 Clinical Features

  • Polyuria and polydipsia
  • Nocturia or enuresis
  • Dehydration and hypernatraemia
  • Low urine osmolality despite high plasma osmolality

69.7.1.3 Diagnosis

  • Water deprivation test (if facilities allow)
  • Low urine specific gravity (<1.005)
  • Response to desmopressin confirms central DI

69.7.1.4 Management

  • Desmopressin (DDAVP) intranasal or oral
  • Adequate hydration
  • Treatment of the underlying cause

Access to desmopressin can be a challenge in Ghana, requiring coordination with major teaching hospitals or pharmacies that stock specialised endocrinology drugs.

69.7.2 Syndrome of Inappropriate ADH Secretion (SIADH)

SIADH results from excess ADH secretion, leading to hyponatraemia with low serum osmolality and concentrated urine.

Common causes include CNS infections, pulmonary disease, or drugs (e.g., carbamazepine).
Management involves fluid restriction, salt supplementation, and addressing the underlying cause.

69.8 Craniopharyngioma and Other Structural Lesions

Craniopharyngioma is a benign but locally aggressive tumour arising from remnants of Rathke’s pouch. It is the most common suprasellar tumour in children and a leading cause of acquired hypopituitarism.

69.8.1 Clinical Features

  • Growth failure and delayed puberty
  • Visual impairment (bitemporal hemianopia)
  • Headache, vomiting due to raised intracranial pressure
  • Diabetes insipidus or other pituitary deficiencies

69.8.2 Diagnosis

  • MRI of the brain: cystic, calcified suprasellar mass
  • Endocrine evaluation for pituitary dysfunction

69.8.3 Management

  • Surgical resection (ideally, subtotal to preserve function)
  • Postoperative hormone replacement (hydrocortisone, thyroxine, GH, DDAVP)
  • Radiation therapy for residual tumour

Children require lifelong follow-up due to the risk of recurrence and permanent panhypopituitarism.

In Ghana, neurosurgical expertise exists in teaching hospitals, but postoperative endocrine support is sometimes inadequate, underscoring the need for closer multidisciplinary collaboration.

69.9 Approach to a Child with Suspected Pituitary Disorder

A structured evaluation includes:

  1. History: growth pattern, perinatal events, head trauma, CNS infections, puberty timing, polyuria/polydipsia
  2. Examination: height/weight, visual fields, facial features, pubertal staging, hydration status
  3. Baseline Investigations:
    • Serum electrolytes, glucose
    • Thyroid function tests
    • Morning cortisol
    • IGF-1 levels
    • LH, FSH, prolactin
  4. Imaging: Pituitary MRI if available
  5. Referral: to a paediatric endocrinologist for specialized testing and management

69.10 Challenges in the Ghanaian Context

  • Limited access to hormone assays (especially GH, IGF-1, cortisol)
  • Lack of standardised growth monitoring in many clinics
  • Cost and availability of hormone replacement (GH, desmopressin)
  • Few centres with multidisciplinary paediatric endocrine teams

Improving training in growth assessment, expanding laboratory capacity, and integrating endocrine screening into routine child health services are key to improving diagnosis and management outcomes.

69.11 Conclusion

Pituitary gland disorders in children, though relatively uncommon, have far-reaching effects on growth, development, and overall health. Early recognition and prompt hormone replacement can transform outcomes.

In Ghana and similar settings, raising clinicians’ awareness, ensuring theavailability of key diagnostic tests, and strengthening referral pathways are vital steps forward. Every child with unexplained growth failure, delayed puberty, or abnormal thirst and urination deserves a careful evaluation of pituitary function.

69.12 Further Reading

  1. Nelson Textbook of Pediatrics, 22nd Edition.
  2. Brook CGD, Clayton PE, Brown RS. Clinical Pediatric Endocrinology, 7th Edition.
  3. Sperling MA. Pediatric Endocrinology, 5th Edition.
  4. Ghana Health Service. National Child Growth Monitoring Guidelines, 2022.
  5. Osei-Kwakye K, et al. “Challenges in Diagnosing Paediatric Endocrine Disorders in Low-Resource Settings: The Ghanaian Perspective.” West African Journal of Medicine, 2021.
  6. WHO. Endocrine Disorders in Childhood: Diagnosis and Management in Resource-Limited Settings,