Natural history of non-functioning pituitary microadenomas: results from the UK non-functioning pituitary adenoma consortium

Abstract

Objective The optimal approach to the surveillance of non-functioning pituitary microadenomas (micro-NFPAs) is not clearly established. Our aim was to generate evidence on the natural history of micro-NFPAs to support patient care. Design Multi-centre, retrospective, cohort study involving 23 endocrine departments (UK NFPA consortium). Methods Clinical, imaging, and hormonal data of micro-NFPA cases between 1/1/2008 and 21/12/2021 were analysed. Results Data for 459 patients were retrieved [median age at detection 44 years [interquartile range (IQR) 31-57) - 152 males/307 females]. 419 patients had more than two MRIs [median imaging monitoring 3.5 years (IQR 1.71-6.1)]. One case developed apoplexy. Cumulative probability of micro-NFPA growth was 7.8% (95%CI 4.9%–8.1%) and 14.5% (95%CI 10.2%–18.8%) at 3 and 5 years, respectively, and of reduction 14.1% (95%CI 10.4-17.8%) and 21.3% (95%CI 16.4-26.2%) at 3 and 5 years, respectively. Median tumour enlargement was 2 mm (IQR 1-3) and 49% of micro-NFPAs that grew became macroadenomas (nearly all >5 mm at detection). Eight (1.9%) patients received surgery (only one had visual compromise with surgery required >3 years after micro-NFPA detection). Sex, age, size at baseline were not predictors of enlargement/reduction. At time of detection, 7.2%, 1.7% and 1.5% patients had secondary hypogonadism, hypothyroidism and hypoadrenalism, respectively. Two (0.6%) developed hypopituitarism during follow-up (after progression to macroadenoma). Conclusions Probability of micro-NFPA growth is low and development of new hypopituitarism is rare. Delaying first follow-up MRI to three years and avoiding hormonal re-evaluation in absence of tumour growth or clinical manifestations is a safe approach for micro-NFPA surveillance.

Comparing redo surgery and stereotactic radiosurgery for recurrent, residual, and/or tumors showing progression in nonfunctioning pituitary adenomas: A systematic review and meta-analysis

“…Visual compromise can occur due to the proximity of the tumor to the optic chiasm and is estimated to be 0.2% of the NFPAs presenting with tumor growth. [8] It is important to was observed here (I 2 = 97%, P < 0.01), as displayed in Figure 12. Revision surgery results in a more exhaustive tumor mass removal due to the physical nature of removal, leading to the prompt alleviation of pressure exerted on adjacent anatomical structures as compared to stereotactic radiosurgery (SRS).…”

“…The probability of tumor growth is estimated to be 7.8% and 14.5% at 3 and 5 years without any intervention in the form of surgery or radiotherapy. [ 8 ] A recurrent pituitary adenoma is defined as a newly developed pituitary adenoma without the evidence of residual tumor on radiological scans at least six months after previous surgery or a growing residual pituitary adenoma on serial postoperative MRI scans. Around 50–60% of adenomas continue to progress after subtotal resection and on long-term follow-up, may recur after GTR in up to 30% of cases.…”

“…Visual compromise can occur due to the proximity of the tumor to the optic chiasm and is estimated to be 0.2% of the NFPAs presenting with tumor growth. [ 8 ] It is important to address the visual field defects as the improvement of quality of life in patients with NFPAs treated with surgical resection is directly related to the visual field improvement. [ 26 ]…”

Strikingly low prevalence of pituitary incidentalomas in a teaching hospital in Uruguay

“…In addition, it was also the indication for imaging of 506 pituitary incidentalomas found in MRI/CT scans in Japan ( 19 ). Furthermore, headaches were the primary reason for undergoing imaging, leading to the detection of 459 non-functioning pituitary microadenomas across 23 endocrine departments in the United Kingdom ( 20 ). Headache has been a symptom associated with small and large non-functioning and functioning pituitary tumors.…”

Diagnosis of hyperprolactinemia in women: A Position Statement from the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo) and the Brazilian Society of Endocrinology and Metabolism (SBEM)

“…Therefore, in cases of small, nonfunctioning pituitary adenomas with mildly elevated prolactin levels, the differentiation between microprolactinoma and nonfunctioning incidentaloma is not as clear initially. Only a reduction in tumor size after treatment with dopaminergic agonists can confirm the diagnosis of prolactinoma, as it is known that nonfunctioning microadenomas increase in size in approximately 10%-20% of cases or remain stable ( 29 , 30 ), while microprolactinomas regress in size or disappear after therapy with dopaminergic agonists in the vast majority of the cases. Notably, a surgical series has shown that approximately 17% of pituitary microadenomas considered to be prolactinomas before surgery were not confirmed to be prolactinomas on immunohistochemistry, showing that they were, in fact, nonfunctioning lesions erroneously diagnosed as prolactinomas due to stalk disconnection ( 31 ).…”