Makindo Medical Notes

Related Subjects: |Adrenal Physiology |Addisons Disease |Phaeochromocytoma |Adrenal Adenomas |Adrenal Cancer |Cushing Syndrome |Cushing Disease |Congenital Adrenal hyperplasia |Primary hyperaldosteronism (Conn's syndrome) |ACTH |McCune Albright syndrome |Male Infertility |Prolactin |Prolactinoma |Sheehan's syndrome

In cases of low 9 am cortisol or inadequate response on short synacthen, always prioritize steroid replacement to manage stress.

About

• Usually benign tumors from the anterior pituitary; incidence of 77 per 100,000.
• Types include hormone-secreting and non-secreting, with macroadenomas (>10mm) and microadenomas (<10 mm).

Aetiology

• Monoclonal benign tumors with various genetic mutations.

Common Tumor Types and Activities

• Prolactinomas (57%), nonfunctioning adenomas (28%), GH-secreting (11%), ACTH-secreting (2%), and TSH-secreting (<1%).

Pathophysiology

• Hormonal effects (e.g., prolactin, GH) often predominate over tumor mass effects.
• Pressure effects may include headache, bitemporal hemianopia, and optic chiasma compression.
• Rarely, may lead to complications like diabetes insipidus and CSF rhinorrhea.

Clinical Manifestations

• Hormonal effects: Elevated prolactin, GH, ACTH, leading to galactorrhea, acromegaly, Cushing's syndrome.
• Pressure symptoms: Bitemporal hemianopia, headache, ophthalmoplegia.
• Hypopituitarism symptoms: Low testosterone, TSH, and cortisol levels, with signs of adrenal insufficiency and hypothyroidism.

Investigations

• Initial hormone levels: 9 am cortisol, PRL, LH, FSH, TSH, testosterone, IGF-1 if acromegaly suspected.
• Imaging: MRI pituitary with sellar views.
• Visual assessment: Goldman perimetry for visual field defects.

Management

• Cushing's Disease: Surgery (trans-sphenoidal), radiotherapy, or medications (ketoconazole, metyrapone).
• Prolactinomas: First-line treatment with dopamine agonists (cabergoline preferred). Surgery reserved for non-responsive cases.
• Acromegaly: Surgery, radiotherapy, and drugs (somatostatin analogues, GH receptor antagonists).
• Nonfunctioning Adenomas: Surgery if compressive; otherwise, observation with regular visual assessments.

Hypopituitarism Management

• Steroids: Hydrocortisone 10 mg morning, 5 mg at noon, and 5 mg evening. Educate on doubling dose during illness.
• Thyroid: Thyroxine 75-150 mcg/day (monitor T4 levels, not TSH).
• Sex Hormones: Testosterone or estrogen/progesterone replacement as needed.
• ADH (for diabetes insipidus): Desmopressin intranasal or oral.

Complications and Follow-Up

• Monitor for CSF leaks, bitemporal hemianopia, and potential for recurrent tumor growth with regular imaging and endocrinology follow-ups.