Normal posterior gland may be included as a small fragment in what is otherwise obviously a pituitary adenoma or some other sellar region mass (Figure 3, f), or may be the majority of a small biopsy sample, especially if the neurosurgeon is resecting a cystic lesion that occurs at the junction between anterior and posterior pituitary gland, that is, a Rathke cleft cyst.
These tumors derive from specialized glial cells in the posterior pituitary gland, but by the time of detection an anterior versus posterior origin is usually not discernible or a distinguishing feature.
An ectopic posterior pituitary gland is a rare condition and may present with an empty pituitary fossa, hypoplasia or absence of the infundibular stalk and resultant short stature due to growth hormone deficiency.
Causes of an ectopic posterior pituitary gland include defective neuronal migration during embryogenesis, tumours, trauma, or surgical transection of the pituitary stalk.
ADH is synthesized by neurons of the supraoptic and paraventricular nuclei of the hypothalamus and stored in the posterior pituitary gland
After all of the ADH stored in the damaged part of the posterior pituitary gland
has been released, hyponatremic phase ends.
Other hormones produced in the hypothalamus are transported through long axons of the nuclei to the posterior pituitary gland
Circumventricular organs surrounding the third ventricle include the subfornical organ, sub-commissural organ, organum vasculosum of the lamina terminalis, pineal gland, posterior pituitary gland
, and part of the median eminence.
This inability could result from injury to the hypothalamus, the supraoptic hypophyseal tract, or the posterior pituitary gland
In summary, normal posterior pituitary gland
shows variable positive staining with GFAP, results that are similar to the staining pattern observed in pituicytomas.