====== Parasellar region ======

{{ ::sellarregion.jpg?500|}}

The area immediately around the [[pituitary]], the [[sellar region]] and parasellar region, is an anatomically complex area that represents a crucial crossroads for important adjacent structures.

The parasellar region is not clearly delineated and includes all the structures that surround the [[sella turcica]].

Vital structures such as the brain [[parenchyma]], [[meninge]]s, [[visual pathway]]s and other [[cranial nerve]]s, major blood vessels, hypothalamopituitary system (HPS) and bony compartments may be involved. 



====Pathologic processes=====
A diversity of clinical symptoms and signs can develop from a number of neoplastic, inflammatory,
infectious, developmental and vascular.

[[pituitary neuroendocrine tumor]], [[pituitary apoplexy]], [[craniopharyngioma]], [[Rathke's cleft cyst]], [[lymphocytic hypophysitis]], and other parasellar lesions
((Pisaneschi M, Kapoor G. Imaging the sella and parasellar region. Neuroimaging 
Clin N Am. 2005 Feb;15(1):203-19. Review. PubMed PMID: 15927868.)).

By drilling off the [[suprameatal tubercle]] and part of the [[petrous apex]], [[Meckel's cave]] may be opened, the [[trigeminal nerve]] mobilized, and the [[tentorium]] divided. Thus the [[parasellar region]] may be exposed and the posterosuperior space of the [[cavernous sinus]] approached. Using an endoscope-assisted technique and following cisternal anatomy, the sellar and parasellar region may be explored even if the working space is narrow. The retrosigmoid intradural suprameatal approach provides optimal accessibility to medially located central skull base structures, in particular to the posterior part of the [[cavernous sinus]]. Use of the endoscope may remarkably optimize the accessibility
((Ebner FH, Koerbel A, Roser F, Hirt B, Tatagiba M. Microsurgical and endoscopic
anatomy of the retrosigmoid intradural suprameatal approach to lesions extending 
from the posterior fossa to the central skull base. Skull Base. 2009
Sep;19(5):319-23. doi: 10.1055/s-0029-1220199. PubMed PMID: 20190941; PubMed
Central PMCID: PMC2765698.
)).