text: The posterior lobe (the neural lobe or neurohypophysis) of the pituitary gland is not, despite its name, a true gland. The posterior lobe contains axons of neurons that extend from the hypothalamus to which it is connected via the pituitary stalk. The hormones vasopressin and oxytocin, produced by the neurons of the supraoptic and paraventricular nuclei of the hypothalamus, are stored in the posterior lobe and released from axon endings (dendrites) within the lobe.
  The pituitary gland's anterior lobe (adenohypophysis) is a true gland which produces and secretes six different hormones: thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), growth hormone (GH), and prolactin (PRL).
  Diagnosis
  Diagnosis of pituitary adenoma can be made, or at least suspected, by a constellation of related symptoms presented above.
  The differential diagnosis includes pituitary tuberculoma, especially in developing countries and in immumocompromised patients. The diagnosis is confirmed by testing hormone levels, and by radiographic imaging of the pituitary (for example, by CT scan or MRI).
  Classification
  Unlike tumors of the posterior Pituitary, Pituitary adenomas are classified as endocrine tumors (not brain tumors). Pituitary adenomas are classified based upon anatomical, histological and functional criteria.
  Anatomically pituitary tumors are classified by their size based on radiological findings; either microadenomas (less than <10 mm) or macroadenomas (equal or greater than ≥10 mm).
  Classification based on radioanatomical findings places adenomas into 1 of 4 grades (I–IV):
  Stage I: microadenomas (<1 cm) without sella expansion.
  Stage II:  macroadenomas (≥1 cm) and may extend above the sella.
  Stage III:  macroadenomas with enlargement and invasion of the floor or suprasellar extension.
  Stage IV: destruction of the sella.