Editing Adrenal lesions


== '''Adrenal incidentaloma''' ==

* Most common lesion to be     incidentally found - about 1% of patients have one, mostly these are     non-functioning
* Uncommon in patients <40yo
* In patients with a history of     malignancy, metastatic disease is most likely, especially when bilateral
* Only investigate if >1cm     in size?

=== Differential diagnosis ===

** '''Functioning'''
*** '''Phaeochromocytoma'''
**** See separate topic
*** '''Cortisol-producing       adrenoma/subclinical Cushing's syndrome'''
**** See separate topic        ('hypercortisolism')
*** '''Aldosteronoma       (aldosterone producing adenoma)'''
**** See separate topic        'hyperaldosteronism' for complete guidelines
**** Less likely to be seen as        incidentaloma, as these are generally small
**** Suspect in any patient        hypertensive and hypokalaemic
*** '''Primary       adrenal hyperplasia'''
** '''Non-functioning'''
*** '''Non-functioning       cortical adenoma'''
**** By far most common        incidentaloma
**** Diagnosis
***** Consistent imaging         appearance and negative biochemical evaluation
***** Two types on CT:
****** Lipid-rich          adenoma (HU <=10): these are the only adrenal incidentals with          such low attenuation and only requires further imaging if there are          other concerning features such as size >4cm. There is good data to          say the sensitivity is as high as 100% for significant lesions if HU          <=10.
****** Lipid-poor          adenoma (HU >10): need to carefully exclude differentials
**** Treatment
***** Adrenalectomy if >4cm         or with imaging characteristics atypical for adenoma
*** '''Myelolipoma'''
**** Benign adrenal lesions        made up of fat and bone marrow elements
**** Can grow up to 15cm and        can be bilateral
**** Diagnosed based on        presence of macroscopic fat on CT/MRI (don't even need to measure HU        because it clearly just looks like fat)
**** Usually asymptomatic
**** Should not be removed        unless atypical appearance or suspected to be causing local symptoms
****
*** '''Adrenal       haemorrhage'''
**** Can occur from trauma or        spontaneous if anticoagulated, especially in the setting of adrenal        tumour
**** Waterhouse-Friderichsen        syndrome - adrenal insufficiency from atraumatic haemorrhage in the        setting of septicaemia
**** Diagnosed on imaging
**** Serial imaging - repeat        3-6 months if felt to be most likely diagnosis
**** In most cases, won't        require adrenalectomy
****
*** '''Adrenal       cyst'''
**** May be endothelial cysts        or pseudocysts from prior haemorrhage or infarction
**** Usually readily        recognisable, although there may be evidence of haemorrhage within them
**** Only require surgery if        they are large and patient is having symptoms
*** '''Ganglioneuroma'''
**** Benign tumours arising        from sympathetic nerve fibres that can be immediately adjacent to        adrenal gland
**** Not functionally active
**** Remove only if diagnosis        uncertain
*** Infection
** '''Malignant'''
*** '''Adrenocortical       carcinoma'''
**** See separate topic
**** About 10% of adrenal        incidentalomas turn out to be these
***** <4cm = 2%
***** 4-6cm = 6%
***** >6cm = 25%
**** Usually large (>6cm)
*** '''Metastases''' to the adrenal gland

== '''Approach to workup''' ==

# Verify that     the lesion is in the adrenal gland
# Determine if the lesion is     hypersecreting adrenal hormones
# Assess whether it is     potentially malignant
# Assess whether there are any     compressive symptoms

== '''Workup:''' ==

* History - HTN, spells     (headaches, palps, anxiety), weight gain, hypokalaemia, other cancer
* '''Screening -     as per algorithm below for ALL patients'''
** '''FBE/UEC/LFT/CMP'''
** '''1mg DMST      then ACTH if abnormal'''
** '''Plasma      renin and aldosterone'''
** '''If      HU>=10: plasma metanephrines and normetanephrines, then if positive do      a 24 hour urine collection'''
** '''If checking      for sex steroid lesions (which is routinely done, but a selective      approach would also be justified), send 24-hour urine testosterone, DHEA,      and DHEA-S or serum DHEAS'''
** '''Imaging of      adrenals'''
* If initial study was an USS,     need a CT (or MRI if suspected phaeochromocytoma)
** Dedicated adrenal CT has a      non-con, arterial, PV and delayed phase
*** <10HU is extremely       reassuring
*** Benign if >60% absolute       washout or >40% relative washout
*** Concerning if irregular       borders, heterogenous (haemorrhage/necrosis), invasion, mets, growth
** FDG PET is good at      distinguishing benign and malignant
* Percutaneous biopsy is not     good
** Primary adrenal malignancy      cannot be diagnosed on cytologic criteria
** ACC can be seeded with      biopsy
** Must exclude phaeo first -      can cause adrenergic crisis
** Sometimes used to diagnose      mets

== '''Usual approach to management:''' ==

* '''No concern.''' Any size and homogenous and     HU <10: lipid-rich adenoma, no further imaging required
* '''Low concern.''' <4cm and homogenous and     HU 11-20: follow-up for 1-2 years
* '''Moderate     concern.''' HU     11-20 and >4cm, or homogenous HU >20 and <4cm, or heterogenous     <4cm: close follow-up vs surgery depending on MDM.
* '''High     concern.''' >4cm     and HU >20: immediate surgery.

== '''Indications for resection:''' ==

* Hormonally active
* Concerning for malignancy     (according to American Association of Clinical Endocrinologists, any     lesion with concerning radiographic characteristics as well as most     lesions 4cm or larger should be resected because of increased cancer risk     - but not including myelolipomas)
** Sabiston suggests remove all      >4cm in fit patients, since CT/MRI underestimate lesion size by 20%
* Relative indications
** Strongly consider removal of      those 3-4cm, especially in young patients
** Suspicious imaging      characteristics, such as heterogeneity, or HU >20
** Growth on interval imaging
** Patient preference

== '''Follow-up''' ==

* Repeat CT at 6-12 months and     then annually for the next 1-2 years for non-op tumours
* Biochemical screening yearly     for 5 years
* Consider excision for lesions     increasing in size (>1cm over 12 months is a good indication for     resection) or that have emerging evidence of hormonal hypersecretion




[[Category:Endocrine]]