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 Pituitary tumours. Prolactinoma

Pituitary Tumours

Pituitary space occupying tumours /lesions

  •  Mass effects , excess hormone secretion,  Hypopituitarism

Infiltration

  • Visual field defects (bitemporal hemianopia)
  • Cavernous sinus – CN 3/4/6  palsy
  • Meninges – headache
  • Hydrocephalus – Ventricle interruption
  • Rhinorrhoea – sphenoid sinus

Diagnosis

MRI > CT, more sensitive

Hormone excess

  • Prolactinoma (chromophobe) , acromegaly/gigantism(acidophile) , cushing/nelson (basophil)
  • Treatment
  • Surgery – trans-sphenoidal, transfrontal (large tumours)
  • Radiotherapy – gamma knife
  • Medical therapy – somatostatin analogues (octreotide),  dopamine agonist

Other tumours

  • Craniopharyngioma – cystic calcified tumour from Rathke pouch (children)
  • Meningioma, gliomas, primary carcinoma – all very rare

Hyperprolactinemia

  • Prolactin promotes milk secretion and inhibits gonadal activity  
  • Inhibited by dopamine
  • Mild increases are physiological (400-600mU/L). Very high mostly likely tumour (>5000mU/L)

Etiology

  • Tumour, stalk compression, polycystic ovary syndrome, idiopathic, dopamine antagonist (metoclopramide/domperidone), anti-emetics, renal/liver failure

Clinical features

  • Galactorrhoea, oligomenorrhoea, decrease libido, subfertility,
  • Osteoporosis – oestrogen/androgen deficiency
  • Gyncomastia , visual loss, headaches

Diagnosis

  • Serum prolactin, IgG (macroprolactinemia)
  • Visual examination
  • Primary hypothyroidism, anterior pituitary function
  • MRI
  • Prolactin >5000mU/L suggests prolactinoma and not due to stalk disconnection

Treatment

  • Cabergoline – once a week (may cause lung/cardiac fibrosis)
  • Bromocriptine – initial [1mg/day] up to [2.5mg/day]

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