Endocrinology, diabetes and metabolic medicine for MRCP Part 1

A 48-year-old man reports that his wedding ring and shoes no longer fit, with increased sweating and headaches over 3 years. He has a prominent jaw, large hands and new hypertension. IGF-1 is markedly raised, and growth hormone fails to suppress during an oral glucose tolerance test. What is the most likely diagnosis?

1. Constitutional large build A naturally large body build rather than disease. That does not match slowly building change in the hands, feet and face with a raised IGF-1 and growth hormone that will not switch off.
2. Pituitary incidentaloma without excess hormone A pituitary growth found by chance that does not make extra hormone. It does not fit slowly building change in the hands, feet and face with a raised IGF-1 and growth hormone that will not switch off.
3. Pseudoacromegaly from insulin resistance Acromegaly-like features without any extra growth hormone. But slowly building change in the hands, feet and face with a raised IGF-1 and growth hormone that will not switch off does not point to it.
4. Familial features Facial features that run in the family. Here, slowly building change in the hands, feet and face with a raised IGF-1 and growth hormone that will not switch off points elsewhere.
5. Acromegaly correct Correct. Slowly building change in the hands, feet and face with a raised IGF-1 and growth hormone that will not switch off is acromegaly.

The point: Acromegaly is caused by too much growth hormone, almost always from a benign growth on the pituitary gland called a somatotroph adenoma, happening after the growth plates in the bones have already fused (before they fuse, the same problem causes gigantism instead). Growth hormone makes the liver produce insulin-like growth factor 1 (IGF-1), and the features build up slowly over years: coarser facial features, a larger jaw and tongue, bigger hands and feet (rings and shoes stop fitting), sweating, headaches, carpal tunnel syndrome (nerve pressure at the wrist), and metabolic problems including poor blood sugar control or diabetes and high blood pressure. A large adenoma can press on the crossing point of the nerves from the eyes (the optic chiasm), causing loss of the outer part of both visual fields (a bitemporal hemianopia), or can reduce the other hormones the pituitary makes. Screening is with a raised IGF-1 blood test; the test that confirms it is growth hormone failing to switch off during a drink of sugar solution (an oral glucose tolerance test), and an MRI scan of the pituitary then finds exactly where the adenoma is. First-choice treatment is an operation through the nose (transsphenoidal surgery); drug treatment with somatostatin analogues (such as octreotide), a drug that blocks the growth hormone receptor (pegvisomant), or dopamine agonists is used when surgery does not fully work, and radiotherapy is a further option. Untreated acromegaly carries a higher risk of dying from heart and blood vessel disease, and a higher risk of bowel polyps and bowel cancer, so treatment aims to bring IGF-1 and growth hormone back to normal.

Source: Society for Endocrinology — acromegaly Society for Endocrinology · tier 2, specialty society or college

A 48-year-old man reports that his wedding ring and shoes no longer fit, with increased sweating and headaches over 3 years. He has a prominent jaw, large hands and new hypertension. IGF-1 is markedly raised, and growth hormone fails to suppress during an oral glucose tolerance test. What is the most appropriate management?

1. Treat the metabolic and cardiovascular complications Diabetes and high blood pressure. Here, slowly building change in the hands, feet and face with a raised IGF-1 and growth hormone that will not switch off points elsewhere.
2. Growth hormone receptor antagonist (pegvisomant) For disease that does not respond to other treatment. But slowly building change in the hands, feet and face with a raised IGF-1 and growth hormone that will not switch off does not point to it.
3. Radiotherapy for residual disease A further option. It does not fit slowly building change in the hands, feet and face with a raised IGF-1 and growth hormone that will not switch off.
4. Transsphenoidal surgery first line correct Correct. Surgery through the nose is the first-choice, definitive treatment for most patients.
5. Dopamine agonist in selected cases For milder disease or tumours that also make another hormone. That does not match slowly building change in the hands, feet and face with a raised IGF-1 and growth hormone that will not switch off.

The point: Acromegaly is caused by too much growth hormone, almost always from a benign growth on the pituitary gland called a somatotroph adenoma, happening after the growth plates in the bones have already fused (before they fuse, the same problem causes gigantism instead). Growth hormone makes the liver produce insulin-like growth factor 1 (IGF-1), and the features build up slowly over years: coarser facial features, a larger jaw and tongue, bigger hands and feet (rings and shoes stop fitting), sweating, headaches, carpal tunnel syndrome (nerve pressure at the wrist), and metabolic problems including poor blood sugar control or diabetes and high blood pressure. A large adenoma can press on the crossing point of the nerves from the eyes (the optic chiasm), causing loss of the outer part of both visual fields (a bitemporal hemianopia), or can reduce the other hormones the pituitary makes. Screening is with a raised IGF-1 blood test; the test that confirms it is growth hormone failing to switch off during a drink of sugar solution (an oral glucose tolerance test), and an MRI scan of the pituitary then finds exactly where the adenoma is. First-choice treatment is an operation through the nose (transsphenoidal surgery); drug treatment with somatostatin analogues (such as octreotide), a drug that blocks the growth hormone receptor (pegvisomant), or dopamine agonists is used when surgery does not fully work, and radiotherapy is a further option. Untreated acromegaly carries a higher risk of dying from heart and blood vessel disease, and a higher risk of bowel polyps and bowel cancer, so treatment aims to bring IGF-1 and growth hormone back to normal.

Source: Society for Endocrinology — acromegaly Society for Endocrinology · tier 2, specialty society or college

A 48-year-old man reports that his wedding ring and shoes no longer fit, with increased sweating and headaches over 3 years. He has a prominent jaw, large hands and new hypertension. IGF-1 is markedly raised, and growth hormone fails to suppress during an oral glucose tolerance test. What is the most appropriate definitive treatment?

1. Treat the metabolic and cardiovascular complications Diabetes and high blood pressure. That does not match slowly building change in the hands, feet and face with a raised IGF-1 and growth hormone that will not switch off.
2. Dopamine agonist in selected cases For milder disease or tumours that also make another hormone. It does not fit slowly building change in the hands, feet and face with a raised IGF-1 and growth hormone that will not switch off.
3. Somatostatin analogue such as octreotide correct Correct. A somatostatin analogue controls growth hormone when surgery does not fully work, or alongside it.
4. Growth hormone receptor antagonist (pegvisomant) For disease that does not respond to other treatment. Here, slowly building change in the hands, feet and face with a raised IGF-1 and growth hormone that will not switch off points elsewhere.
5. Radiotherapy for residual disease A further option. But slowly building change in the hands, feet and face with a raised IGF-1 and growth hormone that will not switch off does not point to it.

The point: Acromegaly is caused by too much growth hormone, almost always from a benign growth on the pituitary gland called a somatotroph adenoma, happening after the growth plates in the bones have already fused (before they fuse, the same problem causes gigantism instead). Growth hormone makes the liver produce insulin-like growth factor 1 (IGF-1), and the features build up slowly over years: coarser facial features, a larger jaw and tongue, bigger hands and feet (rings and shoes stop fitting), sweating, headaches, carpal tunnel syndrome (nerve pressure at the wrist), and metabolic problems including poor blood sugar control or diabetes and high blood pressure. A large adenoma can press on the crossing point of the nerves from the eyes (the optic chiasm), causing loss of the outer part of both visual fields (a bitemporal hemianopia), or can reduce the other hormones the pituitary makes. Screening is with a raised IGF-1 blood test; the test that confirms it is growth hormone failing to switch off during a drink of sugar solution (an oral glucose tolerance test), and an MRI scan of the pituitary then finds exactly where the adenoma is. First-choice treatment is an operation through the nose (transsphenoidal surgery); drug treatment with somatostatin analogues (such as octreotide), a drug that blocks the growth hormone receptor (pegvisomant), or dopamine agonists is used when surgery does not fully work, and radiotherapy is a further option. Untreated acromegaly carries a higher risk of dying from heart and blood vessel disease, and a higher risk of bowel polyps and bowel cancer, so treatment aims to bring IGF-1 and growth hormone back to normal.

Source: Society for Endocrinology — acromegaly Society for Endocrinology · tier 2, specialty society or college