[Ectopia of the pituitary].

Area of Science:

• Endocrinology
• Neuroscience
• Pathology

Background:

• The pituitary gland comprises the adenohypophysis and neurohypophysis, with normal anatomical variations.
• Ectopic pituitary tissue can arise in locations such as the pituitary stalk, pharynx, sphenoid sinus, and cavernous sinus.
• While rare, ectopic tissues like ganglionic cells or adrenocortical tissue have been observed within the pituitary.

Purpose of the Study:

• To review the occurrence and characteristics of ectopic pituitary tissue.
• To differentiate true ectopia from metaplasia in the pituitary gland.
• To highlight the clinical and pathological significance of ectopic pituitary tissues.

Main Methods:

• Literature review of studies reporting ectopic pituitary tissue.
• Histopathological analysis of pituitary tissue samples.
• Review of pituitary malformation syndromes.

Main Results:

• Ectopic pituitary adenomas can develop near extrasellar pituitary tissue and are functionally and structurally similar to intrasellar adenomas.
• The neurohypophysis can exhibit dystopias, notably in pituitary stalk interruption syndrome where it's found at the hypothalamic eminentia mediana.
• Focal squamous epithelia in the anterior pituitary are typically metaplastic, whereas ectopic salivary gland tissue is occasionally found in the intermediate zone.

Conclusions:

• Ectopic pituitary tissues, though rare, can occur in various locations and present similarly to orthotopic pituitary tumors.
• Understanding these ectopic findings is crucial for accurate diagnosis and management of pituitary disorders.
• Distinguishing true ectopia from metaplasia is essential for correct pathological interpretation.