01Purpose and principlesWhat the assessment is for and the core concepts behind it.
Endocrine glands commonly harbour benign structural variants, while hormone disorders may occur in glands that look normal. This weak structure-function correlation makes sequencing decisive. Stable suspected Cushing syndrome should be biochemically confirmed before pituitary or adrenal localisation; supported primary hyperparathyroidism is diagnosed biochemically before neck imaging is used for operative planning; and abnormal thyroid function tests do not by themselves justify ultrasound. Conversely, acute pituitary apoplexy is an anatomical and physiological emergency in which imaging, steroid protection and specialist discussion proceed immediately. The safest request names the diagnostic hypothesis, relevant hormone pattern and consequence expected from a positive or negative scan.
Referral urgency depends on both function and anatomy. Visual-field loss, cranial nerve palsy, altered consciousness, airway symptoms, severe hormone excess, adrenal crisis risk, rapid lesion growth, invasive features or metastatic suspicion need accelerated pathways. Stable incidental findings still deserve disciplined evaluation: review the original images where possible, use gland-specific protocols, screen for clinically relevant secretion, and avoid serial scans that cannot change management. Pregnancy, childhood or young age, syndromic features, a strong family history, previous malignancy and multi-gland disease lower the threshold for specialist or genetic input. Decisions about surgery, surveillance or discharge should be documented by a team familiar with the relevant endocrine condition and regional pathway.
Key points
- For stable endocrine disease, establish a credible biochemical syndrome before looking for its anatomical source; common incidental lesions otherwise create misleading causality.
- Imaging defines location, extent and complications but rarely proves whether a lesion secretes hormone, so anatomical and functional questions must remain separate.
- A thyroid ultrasound is driven by a palpable nodule, cervical lymphadenopathy, compressive concern or surveillance indication, not by an abnormal TSH alone.
- Pituitary MRI follows supported hormone or mass-effect findings; formal visual-field assessment is urgent when the lesion approaches the optic chiasm or vision changes.
- An adrenal mass needs structured radiological characterisation and hormonal assessment; exclude phaeochromocytoma before biopsy or invasive treatment.
- Functioning, indeterminate, enlarging or suspicious endocrine lesions belong in a specialist multidisciplinary pathway where radiology, biochemistry and operative risk are integrated.
- Imaging reports should state size, phenotype, invasion and relevant comparison, while the referrer supplies the exact endocrine question and prior biochemical results.
- Local referral thresholds and access routes vary across UK services; urgent clinical red flags override routine electronic triage.
02Indications, selection and cautionsWhen it is useful, when urgency changes and important limitations.
New visual-field loss, reduced acuity, diplopia, ophthalmoplegia, abrupt headache, vomiting or impaired consciousness requires urgent consideration of apoplexy or chiasmal compression rather than routine outpatient MRI.
A hard or fixed nodule, pathological cervical nodes, rapid enlargement, persistent hoarseness, dysphagia or stridor increases concern and should enter an urgent thyroid and airway-aware pathway.
Paroxysmal headache, palpitations and sweating; resistant hypertension with hypokalaemia; or cortisol-excess features may indicate secretion even when the adrenal mass was found incidentally.
Invasion, heterogeneity, necrosis, suspicious nodes, metastases, rapid interval growth or a phenotype not typical of a benign lesion warrants expert radiology review and multidisciplinary planning.
Young presentation, bilateral or multifocal lesions, recurrent tumours, syndromic features or affected relatives should prompt specialist assessment before isolated local treatment closes the diagnostic pathway.
03Method and interpretationA systematic approach to the test and its findings.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
Dedicated pituitary MRIFirst step - Why
- Define sellar anatomy, optic-chiasm relationship, invasion and a potential source after biochemical or neurological indication.
- Interpretation and limitations
- Size alone does not establish secretion. Correlate with all pituitary axes and visual assessment; an incidental microlesion may be unrelated, whereas chiasmal contact or apoplexy changes urgency.
- 02
Thyroid and cervical-node ultrasound - Why
- Risk-stratify a structural thyroid abnormality and identify nodes requiring targeted sampling.
- Interpretation and limitations
- Use a validated ultrasound grading system and direct fine-needle aspiration according to the reported category and local pathway; ultrasound does not diagnose thyroid functional status.
- 03
Adrenal-protocol CT or MRI - Why
- Characterise size, homogeneity, attenuation or signal and local invasion in an adrenal lesion.
- Interpretation and limitations
- A clearly benign phenotype can limit imaging follow-up, while indeterminate or suspicious findings require endocrine-radiology or adrenal MDT review; biochemical secretion is assessed separately.
- 04
Formal visual-field assessment - Why
- Objectively measure optic-pathway function when a sellar lesion reaches the chiasm or symptoms suggest compression.
- Interpretation and limitations
- A compatible field defect accelerates neurosurgical and ophthalmic discussion. Normal fields provide a surveillance baseline but do not replace imaging or assessment of acuity and ocular movements.
- 05
Endocrine biochemical screen matched to lesion - Why
- Determine whether an anatomical finding is functioning before biopsy, surgery or surveillance is selected.
- Interpretation and limitations
- Testing is lesion-specific: pituitary axes for a sellar lesion and cortisol autonomy, catecholamine excess and aldosterone-renin assessment when indicated for adrenal disease. Positive results change preparation and treatment.
- 06
Tissue sampling through specialist pathway - Why
- Obtain cytology or histology only when it will alter management and the route is safe.
- Interpretation and limitations
- Thyroid cytology is interpreted with ultrasound risk. Adrenal biopsy is rarely first-line, does not distinguish adenoma reliably from cortical carcinoma, and is unsafe until phaeochromocytoma is excluded.
04Clinical next stepsHow the result changes management or prompts escalation.
01SequenceConfirm function before stable localisationFirst stepA stable patient has a possible hormone-excess or deficiency syndrome without acute compression.+
- 1Define and confirm the biochemical phenotype using appropriately timed basal or dynamic tests, reviewing medicines and assay limitations.
- 2Select the gland-specific modality only after the result establishes a localisation question, and include the hormone data in the imaging request.
- 3Reconcile anatomy with physiology in endocrine review; if they conflict, reconsider testing, ectopic sources or an incidental lesion before intervention.
02EscalateRespond to structural red flagsEscalationVisual, neurological, airway or invasive features suggest immediate threat from an endocrine-region lesion.+
- 1Arrange same-day clinical assessment, physiological stabilisation and early discussion with the relevant specialist and radiologist.
- 2Obtain urgent imaging using the local emergency protocol while treating suspected cortisol deficiency or other time-critical endocrine compromise.
- 3Document vision, cranial nerves, airway and consciousness serially, and transfer to a centre with endocrine surgery or neurosurgery when required.
03IncidentalManage a chance imaging findingA pituitary, thyroid or adrenal lesion appears on imaging performed for another reason.+
- 1Verify the site, size, phenotype and previous imaging rather than relying on a nonspecific phrase in the report.
- 2Assess relevant symptoms and secretion with a gland-specific biochemical set, while identifying cancer history, pregnancy, age and hereditary clues.
- 3Use current local or national criteria to choose specialist MDT review, interval imaging or discharge, and communicate a clear endpoint for surveillance.
05Procedure and medicine safetyRelevant preparation, treatment and contraindications.
Hydrocortisone for suspected pituitary apoplexy with adrenal compromise
Give emergency parenteral hydrocortisone promptly according to the Society for Endocrinology and local emergency regimen when haemodynamic instability, altered consciousness or other evidence of acute ACTH deficiency is present.Do not delay treatment for cortisol sampling or MRI. Record timing of any pre-treatment bloods, monitor glucose and electrolytes, and obtain specialist advice for subsequent dosing and taper.
06Risks, monitoring and follow-upComplications, safety checks and further assessment.
- For a surveilled lesion, record the precise imaging parameter that will trigger MDT review, rather than requesting indefinite scans by habit.
- Monitor pituitary lesions with symptom review, relevant axes and formal visual assessment when proximity to the chiasm makes it meaningful.
- Track adrenal or thyroid lesion size using comparable technique and expert reporting; apparent millimetre change may reflect modality or plane rather than biology.
- After intervention, reassess the hormone axis because anatomical removal can create deficiency or reveal previously masked physiology.
- Ensure every imaging report is reconciled with the clinical plan and communicated to the patient, including who owns any interval follow-up.
07Special situationsVariants, exceptions and circumstances that change the usual approach.
Localisation is not diagnosis
A lesion in the expected gland feels persuasive, but secretion must fit. Pituitary and adrenal incidentalomas are common enough to coexist with unrelated symptoms.
Parathyroid imaging plans surgery
Primary hyperparathyroidism is established by calcium-PTH physiology. Ultrasound or nuclear imaging then helps localisation; a negative scan does not erase the biochemical diagnosis.
Biopsy has endocrine prerequisites
Passing a needle into an unrecognised phaeochromocytoma can provoke a catecholamine crisis. Functional assessment therefore precedes any contemplated adrenal biopsy.
Vision is measurable physiology
A patient may not recognise a gradual temporal field deficit. Formal perimetry converts vague visual concern into a baseline that can guide urgency and follow-up.
Request quality changes image value
Stating the biochemical syndrome and suspected gland lets radiology select the right protocol and distinguish a focused question from an incidental search.
08Common pitfallsFrequent interpretation and management errors.
- 01
Ordering thyroid ultrasound to explain an isolated abnormal TSH with no structural neck concern.
- 02
Localising suspected cortisol excess before confirming that hypercortisolism is genuine and reproducible.
- 03
Biopsying an adrenal lesion before excluding phaeochromocytoma and discussing the limited diagnostic role with an adrenal MDT.
- 04
Treating a small pituitary lesion as causal while ignoring a feedback pattern that points to primary target-gland disease.
- 05
Sending acute visual loss through a routine referral form instead of direct same-day specialist contact.
- 06
Continuing surveillance scans without specifying what growth or phenotype change would alter treatment.