Endo/Neuroendo/Urol Flashcards
How should patients with suspected pheochromocytoma be initially investigated?
Plasma free metanephrines (from supine position) and/or urinary fractionated metanephrines
Note this is not vanillymandelic acid (VMA) - which has a high false positive rate
(Endocrine Society Clinical Practice Guidelines 2014)
When is a MIBG scintigraphy indicated in management of phaeo/paraganglioma?
With metastatic disease when radiotherapy using I-MIBG is planned, otherwise use PET-CT
(Meta-iodobenzylguandidine)
(Endocrine Society Clinical Practice Guidelines 2014)
What germline mutation should be tested for in patients with Paragangliomas?
Succinate dehydrogenase (SDH) - about 50% prevalence if present
(Endocrine Society Clinical Practice Guidelines 2014)
How should functional phaeochromocytomas/paragangliomas be managed in the preoperative setting?
A-adrenergic blockers first choice, allowing 7-14 days prep.
Advice re high sodium/fluid diet (to combat intravascular depletion post op)
(Endocrine Society Clinical Practice Guidelines 2014)
A blockers - phenoxybenzamine (irreversible), phentolamine, doxazosin
Often give beta blockade after establishing alpha blockade (labetolol)
How should patients with resected PPGL be monitored?
Annual plasma/urine metanephrines
(Endocrine Society Clinical Practice Guidelines 2014)
When should an open approach be taken to resection of pheochromocytoma?
Large >6cm, invasive tumours - minimise rupture, complete margins
Most paraganlgiomas
Partial can be considered rarely
(Endocrine Society Clinical Practice Guidelines 2014)
How does a phaeochromocytoma differ from a Paraganglioma?
Phaeo is tumour arising adrenomedullary chromatin cells (producing one or more of epinephrine, norepinephrine and dopamine) - about 80-85%.
Paraganglioma 15-20% - extra-adrenal chromatin cells of sympathetic paraveterbral ganglia of thorax, abdomen and pelvis. Can also arise from parasympathetic ganglia along IX and X nerves and base of skull - do not produce catecholamines
What is the prevalence of PPGL among adult hypertensive outpatients?
0.2-0.6% — 1.7% children
5% of incidental adrenal masses
Which syndromes are associated with PPGL?
MEN2a - MTC, HPTH, lichen amyloidosis
MEN2b - MTC, neuromas, intestinal gangliomas (Hirschprungs)
vHL - HAemangiomblasoma, retinal angioma, clear cell RCC, pancreatic NETs and cyst adenomas, papillary cyst adenomas of epididymis
NF1 - neurofibromas, cafe-au-lait spots, freckling, iris harmartomas (Lisch nodules)
What proportion of phaeochromocytomas are bilateral?
10%
10% children, 10% malignant, 10% not hypertensive
How are appendiceal neuroendicine neoplasms most frequently detected?
Incidentally during appendicectomy
(ENETS consensus guidelines 2016)
Which patients with incidentally identified neuroendocrine tumours at appendicectomy do not require further treatment?
<1cm size
Invasion up to subserosa or up to 3mm in mesoappendix
clear surgical margins
Those at base or larger also more likely to recur
(ENETS consensus guidelines 2016)
Where do appendiceal NENs most often appear?
70% at tip
What tumour markers are useful in appendiceal NEN?
Chromogranin A (CgA) - useful to differentiate from goblet cell carcinoma, follow up with metastatic
urinary 5-HIAA in rare patients with carcinoid
(ENETS consensus guidelines 2016)
How are Neuroendocrine tumours graded?
WHO 2010 classification
Ki67 Index (%) and Mitotic Rate (HPF)
G1 NET - Ki ≤2%, MR <2/10
G2 NET - KI 3-20%, MR 2-20/10
G3 NET - KI >20, MR >20
G3s - either poorly differentiated or carcinoma
What is the metastatic rate for appendiceal NETS >2cm?
about 40%
When should a right hemicolectomy be considered with appendiceal NETs 1-2cm in size?
if Base or R1,
or if risk factors - V1,L1, G2/3
(ENETS consensus guidelines 2016)
How often do small intestinal NETs present with metastasis?
50%
How do metastatic small intestinal NETs usually present?
With vague nonspecific symptoms - the carcinoid syndrome is still rare
What symptoms are associated with Carcinoid syndrome?
Secretory diarrhoea (60-80%)
Flushing (60-85%)
Intermittent bronchial wheezing (<10%)
Right heart valve fibrosis - Carcinoid Heart disease, Hedinger syndrome (20%)
Seen with liver metastatic disease bypassing hepatic clearance of serotonin
5% of patients can have retroperitoneal/ovarian tumours/metastases
How should patients be optimally investigated for small intestinal NET?
CT/MRI followed by Ga-DOTATOC PET or SRS Spect
For G3 a FDG PET may be useful
(ENETS consensus guidelines 2016)
What biochemical tests are useful in SI NETs?
Serum Chromogranin A
Urinary 5-HIAA (product of serotonin metabolism) highly sensitive
What are the types of well differentiated gastroduodenal NETs? (3)
Type 1 - ECLoma (Enterochromaffin like cell) - chronic atrophic gastritits
Type 2 - ECLoma -Zollinger Ellison
Type 3 - rare, sporadic, often high grade
If <1cm - endoscopic resection
How should rectal NETs be managed?
If <1cm - Endoscopic resection (unless G3)
>2cm - Anterior resection
1-2cm variable
(ENETS consensus guidelines 2016)