Pituitary gland

The pituitary gland is known as the master gland.

Divisions:

• Anterior pituitary (AKA adenohypophysis).
• Posterior pituitary (AKA neurohypophysis, neural pituitary).

Function

Anterior part:

• Growth hormone (GH).
• Luteinizing hormone (LH)
• Follicle-stimulating hormone (FSH)
• Thyroid stimulating hormone (TSH)
• Adrenocorticotropic hormone (ACTH)
• Prolactin (PRL)

Mnemonic: "Go Look For The Adenoma Please" = GH, LH, FSH, TSH, ACTH, PRL.

Posterior part:

• Oxytocin.
• Antidiuretic hormone (ADH).

Anatomy and histology

Basic anatomy (simplified):

• Anterior:
  • Pars distalis.
  • Pars intermedia.
• Posterior:
  • Pars nervosa.

Embryological origin:

• Anterior - Rathke's pouch (roof of mouth).
• Posterior - diencephalon (ventral aspect).

Image:

• Pituitary gland (ouhsc.edu).

Histology

Anterior

• Acidophils (40% of cells) = red or orange.
  • GH, PRL.
• Basophils (10% of cells) = basophilic (light blue).
  • TSH, LH, FSH.
• Chromophobes (50% of cells) = amphophilic (purplish/grey).

Notes:

• The cellular product (i.e. hormone produced) is not strictly correlated with the cell type.

Posterior

Features:

• Herring bodies - key feature.
  • Eosinophilic axonal dilations filled with lysosomes and neurosecretory granules.
• Less cellular.
  • Usually more cellular in perivascular location.

Image: Herring bodies (ouhsc.edu).

Pituitary adenoma

Features:

• Loss of fibrous stroma.

Rathke cleft cyst

See Head and neck pathology.

• Arises from intermediate lobe.

Craniopharyngioma

See Head and neck pathology.

See also

• Neuropathology.
• Brain tumours.

External links

• Neuropathology - neuropathologyweb.org.