Adrenal gland (331-340) Flashcards
What are the parts of the adrenal gland?;
Zona glomerulosa. Zona fasciculata. Zona reticularis. Medulla.
What hormones are secreted by the adrenal gland?;
Zona golmerulosa- aldosterone (mineralocorticoids). Zona fasciculata- cortisol (corticosteroids). Zona reticularis- androgens. Medulla- adrenaline (catecholamines)
What is the arterial supply to the adrenal gland?;
Superior adrenal artery (branch of inferior phrenic artery). Middle adrenal artery (branch of abdominal aorta). Inferior adrenal artery (branch of renal artery)
What is the venous drainage of the adrenal gland?;
Right adrenal vein drains into inferior vena cava. Left adrenal vein drains into left renal vein.
How would you investigate a patient presenting with an adrenal mass in absence of known malignancy?;
Bloods- U&ES, Renin:Aldosterone ratio, dexamethasone suppresion test. 24 hour Urine metanephrenie. Need bloods & urine to assess if functional or non-functional. Imaging- CT scan usually (>4cm worrying so will need further imaging such CXR to check for mets +/- PET scan +/- MRI with chemical washout of adrenals)
How would you manage a patient presenting with a non-functional (non-secreting) adrenal incidentaloma?;
Discuss at endocrine MDT. Usually if <4cm conservative mx. If >4cm or symtoms needs further ix and may consider removing surgically.
How would you investigate a patient presenting with Cushing’s?;
Dexamethasone supression test. If cortisol level doesn’t lower after low dose dexamethoasone than patient has cushings (cortisol level still high). A normal result is a decrease in cortisol levels upon administration of low-dose dexamethasone.
What are the clinical features of a pheochromocytoma?;
Pheochromocytoma is a tumour of the chromaffin cells of the adrenal medulla. They secrete adrenaline and noradrenaline uncontrollably resulting in high blood pressure. Patient present with palpitations, headache and profuse sweating. 90% are unilateral and benign.
What are the key management principles in a patient with a pheochromocytoma?;
Medical mx (pre op)- Phenoxybenzamine (alpha blocker), labetalol (beta blocker). Surgery- need to be aware BP may drop during surgery when tumour removed.
What are the signs and symptoms of carcinoid syndrome?;
Localised if in GI tract- abdo pain, diarrhoea, constipation, PR bleed. Generalised- weight loss, tiredness, weakness, pellagra (skin lesions), flushing face. Localised if in lungs or mets to lung- wheeze & cough. (80% in GI tract and 20% in lungs)
What substance are produced by a carcinoid tumour?;
5-HT- seretonin. Bradykins. Prostaglandins. Histamine.
How would you manage a patient with a 3.2cm sized carcinoid tumour in the base of the appendix (identified on histology following an appendicetomy)?
Baseline ix- Chromogranin A (protein found inside neuroendocrine cells), urinary 5HAA (breakdown product of seretonin). Medical mx for generalised sx control for carcinoid syndrome- octeride (somastatin analogue), bronchodilators, anti-histamine, manage diarrhoea (e.g. loperamide). Imaging- CT scan to ix for metastasis +/- obstruction. If tumour <2cn & asymptomatic then conservative mx. If tumour >2cm or involves base of appendix or mesentery then requires right hemicolectomy.
What are salient differences between jejunum and the ileum?;
Jejunmum- located in upper left quadrant, thick intestinal wall, longer vasa recta (straight arteries), less arcades (arterial loops), red in colour.
Ileum- located in lower right quadrant, thin intestinal wall, shorter vasa recta, more arcades, pink in colour.
What are the features of a Meckel’s diverticulum?;
Rules of 2’s- 2% population, 2 feet from ileocaeal valve, 2 inches in length, 2 types of ectopic mucosa (gastric and pancreatic), 2 years old (commonest age presentation). Always true diverticulim. Always ante-menteric border. Rement of vitelline cord.
