Common Endocrinology Topics

Recorded live at Swansea School of Medicine, Ed revises pituitary, adrenal and diabetic problems.

 

Lecture by

Video Duration: 68 minutes

  • Prolactinoma
    Created by Eimear McClenaghan
    General
    Epidemiology

    A pituitary adenoma (benign neoplasm of the glandular tissue of the anterior pituitary).

    Pathology

    Hypersecretion of prolactin.

    Top three causes

    None

    Clinical Features
    Symptoms

    Men and Post-Menopausal Women:

    • Late presentation
    • non-specific: morning headache, nausea/vomiting (other symptoms of a space occupying lesion/raised intracranial pressure), visual disturbances if large enough to encroach optic chiasm/CN III/IV/VI

    Menstruating Women

    • Early presentation
    • Galactorrhoea (spontaneous lactation)
    • Menstrual disturbance
    • non-specific: morning headache, nausea/vomiting (other symptoms of a space occupying lesion/raised intracranial pressure), visual disturbances if large enough to encroach optic chiasm/CN III/IV/VI
    Signs

    None

    Investigations
    Cultures

    None

    Bloods

    Basal PRL (raised with prolactinoma)

    Imaging

    MRI Pituitary (glandular mass may be identified)

    Scopic/Biopsy

    None

    Functional

    None

    Treatment
    Conservative

    None

    Medical

    Dopamine agonist: bromocriptine/cabergoline

    Dopamine inhibits prolactin release.

    Surgical

    Transsphenoidal surgery is only entertained if medical therapy does not prove theraputic (i.e. unresponsive/side effects) or patient has intolerable symptoms of a space occupying lesion (visual disturbances).

    Recurrance is common with surgery and a complete pituitary resection results in hypopituitarism (which is obviously less than ideal).

  • Diabetes Insipidus (Cranial)
    Created by Eimear McClenaghan
    General
    Epidemiology

    Form of posterior hypopituitarism.

    Pathology

    Decreased production of ADH/vasopressin by the posterior pituitary/hypothalamus.

    Note that nephrogenic diabetes insipidus can also occur, where the kidneys lose their sensitivity to ADH. The treatment for cranial vs renal diabetes insipidus thus differs greatly as cranial can be corrected by giving an ADH analogue (desmopressin).

    Top three causes
    • Adenoma (usually macro)
    • Mets
    • Iatrogenic (surgery/irradiation)
    • Head Injury
    • Child Birth - ischaemic necrosis: Sheehan's syndrome (not very common clinically but exam favourite)
    Clinical Features
    Symptoms

    Polydipsia and polyurea with hypernatraemia and no glycosurea

    Signs

    None

    Investigations
    Cultures

    None

    Bloods

    None

    Imaging

    None

    Scopic/Biopsy

    None

    Functional

    Water Deprivation Test

    (ability of kidneys to concentrate urine - if ADH is hyposecreted kidneys will be less able to concentrate urine)

    Treatment
    Conservative

    None

    Medical

    If pituitary in origin (i.e. not nephrogenic) a vasopressin/ADH analogue (desmopressin) can be administered. This is usually done intranasally, although oral preparations are available.

    Surgical

    None

  • GH-secreting Adenoma
    Created by Eimear McClenaghan
    General
    Epidemiology

    Functional Pituitary Adenoma (benign neoplasm of glandular tissue of anterior pituitary)

    Pathology

    Increased GH secretion causes soft tissue growth via IGF-1.

    Top three causes

    None

    Clinical Features
    Symptoms

    Kids

    • Gigantism

    Adults

    • Acromegaly:
      • Facial changes (thick skin and lips)
      • Enlargement of hands and feet
      • Excess Sweating
      • Carpal Tunnel syndrome
      • Diabetes
      • Cardiovascular Disease
    Signs

    None

    Investigations
    Cultures

    None

    Bloods

    Serum IGF1

    (25% normal even with raised GH)

    Imaging

    None

    Scopic/Biopsy

    None

    Functional

    Oral Glucose Tolerance Test

    (Glucose suppresses GH in health, if there is no GH suppression it is diagnostic of acromegaly)

    Treatment
    Conservative

    None

    Medical

    If surgery is inappropriate radiotherapy and somatostatin analogues are used.

    Surgical

    Surgical resection is preferred (as long as comorbidities such as diabetes and cardiovascular disease permit).

  • Phaeochromocytoma
    Created by Emily
    General
    Epidemiology

    A catecholamine-releasing tumour. Occur in between 0.5-2 per 1000 individuals with hypertension. No sex difference.

    Pathology

    A neuroendocrine tumour of chromaffin cells. 10% are bilateral, 10% are malignant and 10% are extra-renal ("paragangliomas").

    Top three causes

    1. Sporadic

    2. Familial: MEN2

    3. Familial: neurofibromatosis-1

    Clinical Features
    Symptoms

    Headache, profuse sweating, palpitations, tremor, anxiety, hot flushes

    Signs

    Hypertension, postural hypotension, tremor, ?stigmata of neurofibromatosis (cafe-au-lait spots).

    Investigations
    Cultures

    24 hour urinary catecholamines

    Bloods

    None

    Imaging

    CT adrenals

    Scopic/Biopsy

    None

    Functional

    None

    Treatment
    Conservative

    None

    Medical

    Alpha-blockers (e.g. phenoxybenzamine) initially then beta-blockers (propranolol) for symptomatic relief and to prepare for surgery.

    Surgical

    Resection of tumour.