The diagnosis of pituitary disease is generally uncomplicated. This is despite the high prevalence of occult pituitary adenomas in the general population, the widespread use of high definition imaging techniques, and the broad range of intra- and perisellar lesions that can mimic pituitary adenomas. Follow up and optimisation of pituitary hormone replacement is also relatively straightforward, but management of visual impairment, reduced fertility, coarsened facial features, arthritis, obesity, headaches, and obstructive sleep apnoea is often much more troublesome. The Pituitary Foundation (internet search term: “Pit Pat”) provides important opinion and information, and reassures patients that they are not alone.

In this brief overview, the presentation, classification, and general investigation of pituitary lesions is followed by a discussion of the diagnosis and management of specific secretory subtypes.

PRESENTATION OF PITUITARY ADENOMAS

Inappropriate pituitary hormone secretion and visual field deficits are the most characteristic presenting features of pituitary adenomas. Less specific symptoms such as headache, and subtle signs of pituitary hormone deficiency with peripheral endocrine organ hypofunction characterised by amenorrhoea, loss of libido, and lethargy, are also common. Lymphocytic hypophysitis, pituitary apoplexy, and evidence of more extensive disease such as cranial nerve palsies, temporal lobe epilepsy, hydrocephalus, and cerebrospinal fluid (CSF) rhinorrhoea are fortunately rarer. An exaggerated “physiological” trophic response to prolonged hypothyroidism presenting with visual field defects is well described but is, like pituitary carcinoma, very rare.

CLASSIFICATION OF PITUITARY ADENOMAS

Pituitary adenomas are classified by size and hormone secretory subtype. So-called “silent adenomas”, in which abnormal hormone gene activity is not accompanied by excessive hormone secretion, tend to be more aggressive than truly inactive adenomas. Erosion of the sellar walls and cavernous sinus invasion also suggest a more invasive nature, but estimation of mitotic index and subclassifications based on genetic and ultrastructural studies are research tools without significant clinical utility.

GENERAL INVESTIGATIONS

Imaging

Magnetic resonance imaging (MRI) scanning of the pituitary …