Which of the following statements is not true about adenomas: they are most commonly seen in menopausal women, prior or current use of estrogen (estrogen) is a risk factor, they are soft, encapsulated and are tan to light brown, or they are typically solitary?

Characteristics of Adenomas

The statement that is NOT true about adenomas is that they are most commonly seen in menopausal women. 1

Epidemiology and Demographics of Adenomas

• Pituitary adenomas are very rare before puberty, with prolactinomas being the most common type in children and young people (CYP) under 19 years of age 1
• Pituitary adenomas occur approximately 3-4.5 times more frequently in females than males 1
• Adenomas typically present during adolescence, not during menopause, with median duration of symptom history before diagnosis being about 12 months 1
• In postmenopausal women, the most common solid adnexal mass is a pedunculated leiomyoma (fibroid), not an adenoma 1

Risk Factors for Adenomas

• Prior or current use of estrogen is indeed a risk factor for adenomas, particularly hepatocellular adenomas 2, 3
• Exogenous estrogen is associated with growth of hepatocellular adenomas, while progestin-only agents show less growth or even regression 2
• Unopposed estrogens have been positively associated with adenocarcinomas in some studies 3
• After menopause, hepatocellular adenomas tend to decrease in size, suggesting the role of hormonal influence 4

Physical Characteristics of Adenomas

• Adenomas are soft, encapsulated and are tan to light brown in appearance 1
• Pituitary adenomas can be identified by their characteristic appearance on MRI, with microadenomas (<10mm) typically seen as hypoenhancing lesions 1
• Hepatocellular adenomas may show regression after menopause, with mean diameter decreasing significantly over time 4

Number and Distribution of Adenomas

• Adenomas are typically solitary lesions 1
• In cases where multiple adenomas are present, each should be separately characterized 5
• Fibroadenomas (a type of adenoma) can constitute about 10% of all biopsies in postmenopausal women, but they are not the most common finding in this population 6

Clinical Implications

• Prolactinomas, the most common type of pituitary adenoma, are exceptionally rare before puberty but more common in adolescence 1
• Macroprolactinomas or giant prolactinomas occur more frequently in children and young people than in adults 1
• Hepatocellular adenomas tend to regress after menopause, suggesting that routine follow-up may not be required for small (<5cm) adenomas in postmenopausal women 4

Remember that adenomas are not most commonly seen in menopausal women - they typically present earlier in life, with pituitary adenomas being more common in adolescence and hepatocellular adenomas often regressing after menopause.