Pituitary adenomas are a diverse group of tumors arising from the pituitary gland. The most common health issues associated with these lesions are an increase/decrease of pituitary hormone secretion and/or loss of visual field (mostly due to large tumors that compress parts of the brain that control visual function).72 Other common issues include headache, amenorrhea, loss of libido, and lethargy.72 Standard incidence rates have increased significantly and there are now 5.8/100,000 new cases per year.73
Section 4.1 presents data on functioning adenomas, which secrete hormones and disrupt normal homeostasis and function resulting in disease, such as acromegaly (excess GH), hyperprolactinemia (excess prolactin), and hyperthyroidism (excess thyroid stimulating hormone). Table 12 summarizes data on the overall prevalence of pituitary adenomas.
|POPULATION||DATABASE||PREVALENCE PER 100,000||REFERENCE|
|UK (n=81,149)||Sixteen general practitioner surgeries covering the area of Banbury.||77.6||Fernandez et al., 201074|
|Belgium (n=71,972)||Specialist and general medical practitioner patient populations, referral hospitals, and investigational centers||94||Daly et al. 200675|
Abbreviations: n, number; UK, United Kingdom.
Section 4.2 presents data on non-functioning adenomas, which are pituitary adenomas that are not hormonally active (in other words, not associated with clinical syndromes such as amenorrhea-galactorrhea in the context of prolactinomas, acromegaly, Cushing’s disease, or hyperthyroidism secondary to TSHomas). They account for 15-30% of pituitary adenomas. 98
Section 4.3 summarizes data on non-adenomatous sellar lesions, (e.g., neoplastic, and infiltrative lesions). Valassi et al. analyzed the records of 1,469 transsphenoidal procedures performed between 1998 and 2009 and reported that 116 (7.9%) were not pituitary adenomas.106 Of these 116 patients (45 men, 71 women; mean age 45 years), 53% had cystic lesions, 22% benign neoplasms, 16% malignancies, and 9% inflammatory lesions.106
In addition, Rathke’s cysts, the most common lesions, represented 42% of all cases. Twenty-five per cent of malignant lesions were metastases, and some of the malignancies (e.g., fibrosarcoma, lung metastasis) had a radiographical appearance suggestive of a pituitary adenoma.106
The most common presenting symptoms associated with non-adenomatous lesions were visual field impairment (51%) and headache (34%). Pre-operative pituitary dysfunction was present in 58% of cases, with hyperprolactinemia (35%), hypogonadism (23%), and adrenal insufficiency (23%) found most frequently.106
Postoperative resolution of headache and visual symptoms occurred in 63% and 65% of patients, respectively. Of 64 preoperative endocrine abnormalities, 23 had recovered after surgery (34%). Of these 23, 17 were cases of hyperprolactinemia (77%), three of hypogonadism (14%), two of central hypothyroidism (9%) and one of hypocortisolism. Twelve new cases of endocrine dysfunction occurred after surgery (12/116; 10%).106