Consequences of pituitary disease:

on 11.8.05 with 0 comments



Mechanical effects: the pituitary gland is situated within the sella turcica of the sphenoid bone, at the base of the skull; enlargement may cause

  • Raised intracranial pressure: headache, rarely herniation

  • Bony erosion

  • Local pressure (atrophic or compressive) effects on:

    • Third ventricle

    • Hypothalamus

    • Optic chiasma: visual field defects e.g. bitemporal hemianopia, atrophy

    • Cranial nerves III, IV, V, VI: nerve palsies


Hormonal secretion:

  • Effects vary depending on type of hormone/s affected (secretion and amount)

Note: functioning tumour of one type of pituitary cell (hyperfunction) may cause atrophy (hypofunction) of other types through expansive growth and pressure effects; though 75% specific tissue or cell loss is required to affect function.

Clinical syndromes and pituitary malfunction:



Hormone

Hypersecretion

Hyposecretion

GH

Gigantism (children), acromegaly (adults)

Dwarfism

Prolactin

(Prolactinoma is most common pituitary tumour) Amenorrhoea, galactorrhea and infertility


ACTH

Cushing’s disease

Hypoadrenalism with pigmentation (rather than decrease)

Gonadotrophic (FSH, LH)

Usually silent, rarely testicular enlargement or menstrual irregularities

Hypogonadism

TSH

Hyperthyroidism (very rare)

Cretinism (foetus or infants), hypothyroidism (adult)

ADH

Inappropriate ADH secretion

Diabetes insipidus

Plurihormonal

GH + Prolactin + TSH (& other combinations)

Panhypopituitarism (Simmond’s disease)

Pathological lesion

Hyperplasia (primary or secondary to ectopic promoters of secretion), neoplasia

Surgery, destruction of >75% of gland by tumour, ischaemia (e.g. Sheehan’s syndrome), inflammation, hypothalamic lesions etc.

Tags: ,

Category: Pathology Notes

POST COMMENT

0 comments:

Post a Comment

Newer Post
Older Post
Subscribe to: Post Comments (Atom)