====== Pituitary tumor differential diagnosis ======

Calcifications in pituitary neuroendocrine tumors are reported in 0.2–8% of cases. 

Therefore pituitary neuroendocrine tumors may be mimicked by other tumors located in the sellar region

Although MRI is the imaging study of choice for evaluation of sellar lesion or in the context of known or highly suspected pathology, the MR appearance of different sellar/parasellar lesions may be very similar, which often leads to misdiagnosis. 

While the most common cause of a pituitary mass is an adenoma, the differential diagnosis is broad and includes 

[[Tuberculum sellae meningioma]]

[[Craniopharyngioma]]

[[Rathke cleft cyst]]

[[Metastases]]

[[Glioma]]s

Abscess, as well as uncommon types of sellar/parasellar tumors like [[hemangioblastoma]].

[[Pituitary hyperplasia]]

[[Lymphocytic hypophysitis]] 

[[pituitary neuroendocrine tumor]].

[[Neurohypophyseal tumor]]s are rare.

The term [[atypical adenoma]] (APA) was revised in the old 2004 World Health Organization (WHO) classification of [[pituitary tumor]]s.