Drug-Related Hypophysitis After Immune Checkpoint Inhibitor Therapy: MRI Findings, Diagnostic Reasoning, and the Clinical Significance of Pituitary Stalk Thickening
Headache and Visual Blurring May Be the First Clues to an Endocrine Immune-Related Adverse Event
Headache and blurred vision are common clinical complaints, but their significance changes when they occur in a patient receiving immune checkpoint inhibitor therapy. When new headache, fatigue, nausea, visual symptoms, or unexplained weakness are accompanied by central endocrine abnormalities, immune checkpoint inhibitor-related hypophysitis should be considered.
This case describes a man in his late 30s who presented with headache and blurred vision and was found to have central hypothyroidism. A previous noncontrast brain CT showed no obvious abnormality, whereas subsequent pituitary MRI demonstrated enlargement of the pituitary gland and thickening of the pituitary stalk. The clinical history of melanoma and immune checkpoint inhibitor therapy provided a critical diagnostic clue.
The key MRI pattern included symmetric pituitary enlargement, pituitary stalk thickening with midline preservation, loss of the posterior pituitary bright spot, and diffuse mild heterogeneous enhancement. In this clinical setting, the combined findings supported a diagnosis of drug-related hypophysitis.
The important lesson is not simply to recognize an enlarged pituitary gland. The radiologist must connect the shape, symmetry, stalk, enhancement pattern, endocrine findings, medication history, and clinical timeline into a single diagnostic framework.
Why This Case Matters
Immune checkpoint inhibitors (ICIs) have transformed cancer treatment by enhancing antitumor immune responses. However, immune activation can also affect normal organs and produce immune-related adverse events (irAEs).
The pituitary gland is one of the endocrine organs that can be affected.
This becomes particularly important with ipilimumab, a cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) inhibitor. Hypophysitis is also reported with programmed cell death protein 1 (PD-1) inhibitors such as nivolumab and pembrolizumab, although the clinical and imaging patterns may differ.
For radiologists, this creates an important diagnostic situation:
A patient with cancer may have a new sellar abnormality for several different reasons.
The lesion could represent an adenoma, metastasis, inflammatory disease, or another sellar or suprasellar process. In a patient receiving immunotherapy, however, the medication history may substantially change the interpretation of the same MRI findings.
What Is Drug-Related Hypophysitis?
Hypophysitis refers to inflammatory involvement of the pituitary gland and, in some cases, the pituitary stalk.
Historically, lymphocytic autoimmune hypophysitis was classically associated with pregnancy and the postpartum period. The widespread use of immune checkpoint inhibitors has expanded the clinical spectrum and increased the importance of recognizing treatment-related hypophysitis.
Immune checkpoint inhibitors target regulatory pathways that normally restrain T-cell activation. Important immune checkpoints include:
CTLA-4
PD-1
PD-L1
Blocking these pathways can enhance antitumor immunity, but immune activation may also affect normal tissues.
Endocrine immune-related adverse events may include thyroid dysfunction, adrenal dysfunction, diabetes mellitus, and hypophysitis.
Among ICIs, ipilimumab has a particularly well-established association with hypophysitis. Reported frequencies vary according to study population, treatment regimen, dosage, combination therapy, and diagnostic criteria.
Therefore, the medication history should not be treated as background information. In an appropriate clinical setting, it becomes part of the imaging diagnosis.
The Clinical Presentation: More Than Just a Headache
Drug-related hypophysitis can present with a variety of symptoms.
Headache
Headache is one of the most important presenting symptoms. It may reflect inflammation and enlargement of the pituitary gland or mass effect on adjacent structures.
Fatigue
Fatigue is nonspecific, but it becomes more clinically meaningful when accompanied by pituitary hormone deficiencies, particularly abnormalities involving the adrenal or thyroid axes.
Nausea and Vomiting
These symptoms may occur with endocrine dysfunction and are particularly important when adrenal insufficiency is suspected.
Visual Symptoms
Pituitary enlargement may extend superiorly toward the optic chiasm. Visual symptoms may therefore occur when the chiasm is compressed.
Although classic bitemporal hemianopia can occur, patients may initially describe the problem simply as blurred vision or a change in visual field.
Gonadal Dysfunction
Men may develop reduced testosterone levels, decreased libido, and fatigue when gonadal function is impaired.
Central Hypothyroidism
Central hypothyroidism is an important diagnostic clue.
A normal or low-normal thyroid-stimulating hormone (TSH) level does not necessarily indicate normal thyroid function when pituitary disease is present. Free thyroxine (free T4) must be interpreted together with TSH and the clinical context.
This distinction is especially important because pituitary disease can produce an inappropriately low or normal TSH despite low free T4.
The Endocrine Emergency That Should Not Be Missed: Secondary Adrenal Insufficiency
One of the most clinically important consequences of hypophysitis is secondary adrenal insufficiency caused by reduced adrenocorticotropic hormone (ACTH).
Reduced ACTH can lead to inadequate cortisol production.
Severe adrenal insufficiency may progress to adrenal crisis, with findings such as:
Hypotension
Dehydration
Hyponatremia
Hypoglycemia
Altered mental status
For this reason, endocrine evaluation may include:
Morning cortisol
ACTH
TSH
Free T4
Electrolytes
LH
FSH
Testosterone
Prolactin when clinically appropriate
Additional pituitary function testing when indicated
A particularly important treatment principle is the sequence of hormone replacement.
When adrenal insufficiency is suspected, cortisol deficiency should be addressed before thyroid hormone replacement. Initiating thyroid hormone in a patient with untreated cortisol deficiency may increase metabolic demand for cortisol and potentially precipitate or worsen adrenal crisis.
This is an example of why imaging interpretation cannot be separated from clinical management.
Why Pituitary MRI Is More Important Than a Routine Noncontrast CT
In this case, a previous noncontrast brain CT did not demonstrate an obvious abnormality.
That finding should not be interpreted as evidence against pituitary disease.
Routine noncontrast brain CT has limited sensitivity for subtle pituitary enlargement, pituitary stalk thickening, and other small sellar abnormalities.
When clinical suspicion remains high, dedicated pituitary MRI with contrast provides substantially more useful structural information.
A systematic MRI assessment should include:
Pituitary gland size
Overall gland contour
Symmetry
Pituitary stalk thickness
Stalk position
T1 signal
T2 signal
Posterior pituitary bright spot
Enhancement pattern
Relationship to the optic chiasm
Dural enhancement when present
Adjacent sphenoid sinus findings
The central principle is simple:
Do not stop at “the pituitary is enlarged.”
The pattern of enlargement often carries more diagnostic information than size alone.
MRI Findings in This Case
Figure 1. Sagittal T1-Weighted MRI
The sagittal T1-weighted image demonstrates superior convex enlargement of the pituitary gland.
The normal posterior pituitary T1 hyperintensity, commonly referred to as the posterior pituitary bright spot, is not clearly visualized.
Why It Matters
Pituitary enlargement combined with loss of the posterior pituitary bright spot can support the diagnosis of hypophysitis in the appropriate clinical context.
However, loss of the bright spot alone does not establish diabetes insipidus. Imaging findings must be correlated with clinical and endocrine findings.
Figure 1. Sagittal T1-weighted MRI demonstrates enlarged superiorly convex pituitary tissue with loss of the expected posterior pituitary bright spot.
ALT text:
Sagittal T1-weighted pituitary MRI showing enlarged pituitary gland and absent posterior pituitary bright spot.
Figure 2. Coronal T1-Weighted MRI
The coronal T1-weighted image demonstrates diffuse enlargement of the pituitary gland with a relatively symmetric configuration.
Rather than appearing as a discrete unilateral mass, the gland is enlarged as a whole.
The Diagnostic Clue: Symmetry
Symmetric gland enlargement is an important clue favoring an inflammatory process such as hypophysitis.
By contrast, a pituitary adenoma more commonly produces a focal or asymmetric mass, although imaging appearances can overlap.
The important question is therefore not simply:
“Is the pituitary enlarged?”
but:
“How is the pituitary enlarged?”
Figure 2. Coronal T1-weighted MRI demonstrates relatively symmetric enlargement of the pituitary gland.
ALT text:
Coronal T1-weighted pituitary MRI demonstrating symmetric gland enlargement.
Figure 3. Coronal T2-Weighted MRI
The coronal T2-weighted image demonstrates relatively homogeneous signal intensity within the enlarged pituitary gland.
An inflammatory lesion does not necessarily have to demonstrate strikingly high T2 signal intensity.
Therefore, T2 signal alone should not be used to diagnose or exclude hypophysitis.
A more reliable approach integrates T1-weighted imaging, T2-weighted imaging, postcontrast sequences, gland morphology, stalk appearance, and clinical endocrine abnormalities.
Figure 3. Coronal T2-weighted MRI demonstrates diffuse pituitary enlargement without a strikingly hyperintense T2 pattern.
ALT text:
Coronal T2-weighted MRI showing diffuse enlargement of the pituitary gland.
Figure 4. Early Postcontrast Coronal T1-Weighted MRI
Early postcontrast imaging demonstrates enhancement centered within the pituitary gland.
The vascular characteristics of the normal pituitary gland and inflammatory changes associated with hypophysitis can influence the enhancement pattern.
Dynamic contrast-enhanced pituitary MRI may therefore provide useful information when differentiating normal glandular enhancement, inflammatory disease, and sellar neoplasms.
However, enhancement alone is not diagnostic.
Figure 4. Early postcontrast coronal T1-weighted MRI demonstrates pituitary enhancement in the enlarged gland.
ALT text:
Early postcontrast coronal T1-weighted pituitary MRI demonstrating glandular enhancement.
Figure 5. Late Postcontrast Coronal T1-Weighted MRI
The delayed postcontrast image demonstrates mild diffuse heterogeneous enhancement of the enlarged pituitary gland.
Diffuse or heterogeneous enhancement can occur in hypophysitis and may contribute to the overall diagnostic pattern.
Nevertheless, enhancement characteristics should always be interpreted together with gland morphology, stalk appearance, endocrine abnormalities, and treatment history.
Figure 5. Late postcontrast coronal T1-weighted MRI demonstrates mild diffuse heterogeneous enhancement of the enlarged pituitary gland.
ALT text:
Late postcontrast coronal T1-weighted MRI showing diffuse heterogeneous enhancement of the pituitary gland.
Figure 6. Sagittal Late Postcontrast T1-Weighted MRI
This image demonstrates two particularly important findings:
Enlargement of the pituitary gland
Thickening of the pituitary stalk
The stalk remains in the midline.
Why Pituitary Stalk Thickening Matters
Pituitary stalk thickening is one of the most useful imaging clues in this case.
In inflammatory hypophysitis, the stalk may become thickened while maintaining a relatively midline position.
In contrast, a focal pituitary mass may displace the stalk away from the lesion.
This does not constitute an absolute rule, but it is an important pattern-recognition clue.
Figure 6. Sagittal late postcontrast T1-weighted MRI demonstrates enlarged pituitary tissue and thickened pituitary stalk with preservation of the midline position.
ALT text:
Sagittal postcontrast pituitary MRI showing gland enlargement and midline pituitary stalk thickening.
Hypophysitis vs. Pituitary Adenoma: What Should the Radiologist Look For?
The most important imaging differential diagnosis in this setting is often a nonfunctioning pituitary adenoma.
Both hypophysitis and pituitary adenoma can enlarge the gland and potentially affect the optic chiasm.
The distinction therefore requires pattern recognition rather than reliance on a single imaging feature.
| Imaging / Clinical Feature | Hypophysitis | Pituitary Adenoma |
|---|---|---|
| Overall gland | Often symmetric enlargement | More often focal or asymmetric mass |
| Pituitary stalk | May be thickened | Often displaced by a mass |
| Stalk position | May remain midline | May deviate away from the lesion |
| Gland contour | Diffuse or convex enlargement | Focal mass effect |
| Enhancement | Diffuse, homogeneous, or heterogeneous | Variable depending on tumor |
| Posterior bright spot | May be absent | More often preserved |
| Endocrine dysfunction | Common | Variable |
| ICI exposure | Important clinical clue | Not directly associated |
None of these findings should be considered an absolute diagnostic criterion.
The diagnosis emerges from the combination of imaging pattern + endocrine profile + medication exposure + clinical course.
The Critical Differential Diagnosis in a Cancer Patient: Hypophysitis or Metastasis?
For patients with malignancy, particularly melanoma, the differential diagnosis becomes more complicated.
A pituitary lesion in a patient with cancer can represent:
Pituitary adenoma
Hypophysitis
Pituitary metastasis
Pituitary apoplexy
Pituitary hyperplasia
Craniopharyngioma
Germinoma
Lymphoma
Meningioma
Melanoma is clinically important because metastatic disease must be considered.
Pituitary metastases can involve the posterior pituitary and stalk and may be associated with diabetes insipidus.
ICI-related hypophysitis, on the other hand, may present prominently with anterior pituitary hormone deficiencies.
However, neither diagnosis can be established reliably from one MRI feature alone.
A practical four-part framework is:
1. Cancer history
What malignancy does the patient have, and what is the current disease status?
2. Treatment history
Which immune checkpoint inhibitor is being used?
3. Endocrine abnormalities
Which pituitary hormone axes are abnormal?
4. MRI morphology
Is the gland symmetrically enlarged? Is the stalk thickened? Is the stalk midline? What is the enhancement pattern?
The diagnostic story becomes stronger when these four elements point in the same direction.
Why Treatment History Changes the MRI Interpretation
The same pituitary enlargement can have different meanings in different patients.
Consider two simplified clinical scenarios.
A patient with no history of cancer or immunotherapy develops a focal sellar mass.
Another patient with melanoma receiving an immune checkpoint inhibitor develops headache, blurred vision, central hypothyroidism, symmetric pituitary enlargement, and stalk thickening.
The MRI cannot be interpreted in isolation.
In the second scenario, the medication history is not merely an additional clinical detail. It becomes a major part of the differential diagnosis.
This is one of the most important principles in modern oncologic imaging:
Imaging phenotype and treatment phenotype must be interpreted together.
What Can Be Missed?
Several diagnostic vulnerabilities are particularly relevant to this type of case.
1. Anchoring on the cancer diagnosis
When a patient with melanoma develops a new intracranial symptom, there may be an immediate focus on metastatic disease.
Metastasis must certainly be considered, but it should not automatically explain every new neurologic or endocrine symptom.
2. Satisfaction of search after a normal CT
A normal noncontrast brain CT can create false reassurance.
Small sellar and stalk abnormalities may be difficult to detect on routine CT.
3. Focusing only on gland size
An enlarged pituitary gland is not synonymous with adenoma.
Symmetry, stalk morphology, enhancement, and clinical context matter.
4. Ignoring the stalk
The stalk can provide a major diagnostic clue.
Its thickness and position should be deliberately assessed rather than treated as a secondary observation.
5. Ignoring endocrine findings
Central hypothyroidism or adrenal insufficiency may provide the clinical bridge between the MRI and the final diagnosis.
A Practical Diagnostic Algorithm
Treatment: The Goal Is Not Simply to Normalize the MRI
Treatment of drug-related hypophysitis is primarily directed toward clinically important hormone deficiencies and the severity of inflammation or mass effect.
Possible strategies include:
Hormone replacement
Hormone replacement is central when pituitary hormone deficiencies are present.
Glucocorticoid replacement is particularly important in secondary adrenal insufficiency.
Levothyroxine may be used for central hypothyroidism, but adrenal insufficiency must be considered first.
Corticosteroid therapy
High-dose corticosteroids may be considered in selected patients with substantial inflammatory enlargement or significant mass effect.
However, reducing pituitary size on MRI does not necessarily mean that pituitary endocrine function will recover completely.
Management of the causative immunotherapy
Whether an immune checkpoint inhibitor should be temporarily withheld, discontinued, or resumed requires consideration of both the cancer status and severity of the immune-related adverse event.
This decision belongs to the treating oncology and endocrine teams rather than being determined by imaging alone.
Follow-Up MRI: Why Time Matters
In this case, treatment included:
Discontinuation of ipilimumab
Hormone replacement
Corticosteroid therapy
Follow-up MRI demonstrated normalization of pituitary size.
This is an important imaging observation because inflammatory pituitary enlargement may improve over time.
However, an apparently normal pituitary MRI does not necessarily mean complete endocrine recovery.
Pituitary hormone deficiencies may persist even after the structural abnormality improves.
Therefore:
Radiologic recovery and endocrine recovery are not necessarily the same event.
Long-term follow-up should consider both MRI findings and pituitary function.
Figure 7. Follow-Up Sagittal T2-Weighted MRI
The follow-up sagittal T2-weighted MRI demonstrates the later appearance of the pituitary after treatment.
The case describes normalization of pituitary size during follow-up.
This illustrates the dynamic nature of inflammatory pituitary disease.
Acute hypophysitis may initially produce gland enlargement and stalk thickening. With resolution of inflammation, the gland may return toward normal size, although pituitary atrophy or persistent endocrine dysfunction can occur in some patients.
Figure 7. Follow-up sagittal T2-weighted MRI after treatment demonstrates normalization of pituitary size.
ALT text:
Follow-up sagittal T2-weighted pituitary MRI after treatment showing normalized pituitary size.
The Five-Point Pituitary MRI Checklist
When reviewing a pituitary MRI in a patient receiving immune checkpoint inhibitor therapy, five questions provide a practical starting point.
Check 1 — Size
Is the pituitary gland enlarged?
Check 2 — Shape
Is the enlargement symmetric, or is there a focal asymmetric mass?
Check 3 — Stalk
Is the pituitary stalk thickened?
If so, does it remain in the midline or is it displaced?
Check 4 — Posterior Bright Spot
Is the posterior pituitary T1 bright spot visible?
Check 5 — Clinical Context
Is the patient receiving an immune checkpoint inhibitor?
Are there abnormalities involving the ACTH-cortisol axis or TSH-free T4 axis?
This checklist is simple, but it helps prevent an important diagnostic error: interpreting pituitary morphology without considering the patient's treatment history and endocrine function.
Can Hypophysitis Occur When MRI Looks Nearly Normal?
Yes.
This is particularly important in ICI-related disease associated with PD-1 or PD-L1 inhibition.
Not all patients demonstrate the classic pattern of marked pituitary enlargement.
Therefore, a near-normal MRI should not automatically exclude immune checkpoint inhibitor-related pituitary dysfunction.
The diagnostic process should remain:
Symptoms → Medication history → Hormonal evaluation → MRI → Follow-up
This is especially important when endocrine abnormalities are already present.
AI Perspective: Where Can Clinical AI Help?
This case also illustrates a realistic role for artificial intelligence in medical imaging.
The most useful AI opportunity is not to replace the radiologist's diagnosis. Instead, AI could support structured detection and workflow consistency.
For example, a clinical AI system could potentially assist with:
Pituitary gland localization
Pituitary size measurement
Pituitary stalk measurement
Comparison with prior MRI examinations
Structured documentation of sellar abnormalities
Identification of cases requiring focused pituitary review
Integration of imaging findings with structured clinical information
A future workflow might conceptually look like:
DICOM images
↓
PACS
↓
AI orchestration
↓
Pituitary localization / quantitative analysis
↓
Structured imaging output
↓
Radiologist review
↓
RIS / EHR
↓
Clinical decision support
But important limitations remain.
AI may produce:
False-negative findings
False-positive findings
Measurement errors
Errors caused by poor image quality
Domain shift between institutions
Anatomical mislocalization
Unexpected pathology
Automation bias
The radiologist must therefore remain responsible for clinical interpretation.
The appropriate role of AI is decision support, not decision replacement.
A Healthcare Workflow Lesson From This Case
The diagnostic pathway for hypophysitis crosses multiple clinical departments.
A patient may first present to:
Emergency medicine
Oncology
Primary care
Ophthalmology
Neurology
Radiology
The diagnosis may ultimately require coordination with:
Endocrinology
Medical oncology
Radiology
This creates a potential workflow vulnerability.
If the medication history is unavailable to the radiologist, the imaging may be interpreted without the most important clinical clue.
If endocrine abnormalities are not recognized, the MRI finding may be underestimated.
If a normal CT is considered sufficient, dedicated pituitary MRI may be delayed.
The lesson is therefore broader than this individual case:
Clinical context is a data layer in medical imaging.
A modern imaging workflow should make relevant medication exposure, cancer history, endocrine laboratory abnormalities, and prior imaging accessible at the point of interpretation whenever possible.
Diagnostic Risk: Where the Miss Can Occur
The potential diagnostic pathway can be understood as:
Missed endocrine abnormality à Delayed recognition of hypophysitis à Delayed hormone replacement à Potential clinical deterioration
At the imaging level:
Normal or nonspecific CT à False reassurance à Delayed pituitary MRI à Delayed recognition of sellar inflammation
This does not imply individual clinician error. These vulnerabilities can arise from high-volume workflows, incomplete clinical information, competing diagnostic priorities, and fragmented health information systems.
That is precisely where structured reporting, clinical decision support, and carefully designed AI tools may eventually contribute.
Clinical Pearls
Headache in a patient receiving immune checkpoint inhibitor therapy is not always a brain metastasis.
Central hypothyroidism may present with a low or inappropriately normal TSH despite reduced free T4.
Secondary adrenal insufficiency is one of the most clinically important complications of hypophysitis.
A normal noncontrast brain CT does not exclude pituitary disease.
Symmetric pituitary enlargement favors an inflammatory process over a typical focal adenoma pattern.
Pituitary stalk thickening is an important MRI clue.
Midline preservation of a thickened stalk can support hypophysitis in the appropriate context.
Loss of the posterior pituitary bright spot is supportive but is not, by itself, diagnostic of diabetes insipidus.
Pituitary metastasis remains an important differential diagnosis in patients with cancer.
Structural recovery on MRI does not necessarily mean complete endocrine recovery.
Common Pitfalls in Pituitary MRI Interpretation
Pitfall 1: “The CT is normal, so the pituitary is normal.”
Not necessarily. Dedicated pituitary MRI is more appropriate when clinical suspicion persists.
Pitfall 2: “The pituitary is enlarged, so this is an adenoma.”
Diffuse symmetric enlargement and stalk thickening should prompt consideration of hypophysitis.
Pitfall 3: “The patient has melanoma, so this must be metastasis.”
Metastasis is an important differential diagnosis, but treatment-related hypophysitis may produce a very different clinical-radiologic pattern.
Pitfall 4: “The MRI is almost normal, so hypophysitis is excluded.”
ICI-related pituitary dysfunction may occur without dramatic gland enlargement.
Pitfall 5: “The MRI has normalized, so the disease has completely resolved.”
Endocrine dysfunction may persist after structural improvement.
Frequently Asked Questions
What is the key MRI finding of immune checkpoint inhibitor-related hypophysitis?
In the classic imaging pattern illustrated by this case, the major findings include symmetric pituitary enlargement, pituitary stalk thickening with possible midline preservation, loss of the posterior pituitary bright spot, and diffuse or heterogeneous enhancement.
What is the most important differential diagnosis?
A nonfunctioning pituitary adenoma is a major differential diagnosis. In a patient with cancer, pituitary metastasis must also be considered.
Is CT sufficient to diagnose hypophysitis?
Routine noncontrast brain CT may miss subtle pituitary and stalk abnormalities. When clinical suspicion is present, dedicated pituitary MRI is more informative.
Why is the pituitary stalk important?
Stalk thickness and position provide useful morphologic information. Thickening with relative preservation of the midline position may support an inflammatory process.
Can ICI-related hypophysitis occur without pituitary enlargement?
Yes. Particularly with PD-1 or PD-L1 inhibitors, MRI may show little or no obvious pituitary enlargement despite clinically significant pituitary dysfunction.
Why is free T4 important when TSH is normal?
Pituitary disease can produce an inappropriately low or normal TSH despite reduced free T4. Therefore, TSH should not be interpreted in isolation when central hypothyroidism is suspected.
Why must adrenal insufficiency be considered before thyroid replacement?
If cortisol deficiency is present, thyroid hormone replacement can increase the physiological demand for cortisol and may worsen adrenal insufficiency. Clinical assessment of the adrenal axis is therefore important before thyroid hormone replacement when adrenal insufficiency is suspected.
Does normalization of pituitary size mean complete recovery?
No. MRI normalization does not necessarily indicate recovery of all pituitary hormone axes. Long-term endocrine follow-up may remain necessary.
Key Takeaways
Drug-related hypophysitis is an important immune-related adverse event in patients receiving immune checkpoint inhibitor therapy.
The diagnosis depends on more than pituitary enlargement.
The most useful imaging approach is to evaluate:
Gland size
→ Symmetry
→ Stalk thickness
→ Stalk position
→ Posterior bright spot
→ Enhancement pattern
→ Optic chiasm relationship
These findings should then be integrated with:
Cancer history
Immune checkpoint inhibitor exposure
Pituitary hormone abnormalities
Clinical symptoms
Temporal evolution
In this case, the combination of melanoma history, ipilimumab exposure, headache and visual blurring, central hypothyroidism, symmetric pituitary enlargement, stalk thickening, midline stalk position, and characteristic enhancement supported the diagnosis of drug-related hypophysitis.
The broader lesson is equally important.
A good radiology interpretation does not end by describing what the image looks like. It explains what the image means in the clinical context and how that interpretation may influence the next clinical decision.
Continue Learning
Pituitary MRI and Sellar Lesions
Explore the major MRI findings used to characterize pituitary enlargement and distinguish inflammatory disease from neoplastic lesions.
Differential Diagnosis of Pituitary Stalk Thickening
Review the broad differential diagnosis of stalk abnormalities, including inflammatory, neoplastic, infiltrative, and metastatic disease.
Immune Checkpoint Inhibitors and Endocrine Immune-Related Adverse Events
Understand how modern cancer immunotherapy can produce clinically important endocrine complications.
Radiology AI and Clinical Workflow
Explore how AI may support detection, quantitative assessment, structured reporting, and clinical workflow without replacing radiologist oversight.
References
Caranci F, Leone G, Ponsiglione A, et al. Imaging findings in hypophysitis: A review. La Radiologia Medica. 2020;125(3):319–328. doi:10.1007/s11547-019-01120-x.
Faje A, Reynolds K, Zubiri L, et al. Hypophysitis secondary to nivolumab and pembrolizumab is a clinical entity distinct from ipilimumab-associated hypophysitis. European Journal of Endocrinology. 2019;181(3):211–219. doi:10.1530/EJE-19-0238.
Shih RY, Schroeder JW, Koeller KK. Primary tumors of the pituitary gland: Radiologic-pathologic correlation. RadioGraphics. 2021;41(7):2029–2046. doi:10.1148/rg.2021200203.
Gutenberg A, Larsen J, Lupi I, Rohde V, Caturegli P. A radiologic score to distinguish autoimmune hypophysitis from nonsecreting pituitary adenoma preoperatively. AJNR American Journal of Neuroradiology. 2009;30(9):1766–1772. doi:10.3174/ajnr.A1714.
Tsoli M, Kaltsas G, Angelousi A, et al. Managing ipilimumab-induced hypophysitis: Challenges and current therapeutic strategies. Cancer Management and Research. 2020;12:9551–9561. doi:10.2147/CMAR.S224791.
Joshi MN, Whitelaw BC, Palomar MTP, Wu Y, Carroll PV. Immune checkpoint inhibitor-related hypophysitis and endocrine dysfunction: Clinical review. Clinical Endocrinology. 2016;85(3):331–339. doi:10.1111/cen.13063.
Iglesias A. Immune-Mediated Hypophysitis: An Updated Review. Journal of Clinical Medicine. 2026;15(9):3313. doi:10.3390/jcm15093313.
Quandt Z, Young A, Perdigoto AL, Herold KC, Anderson MS. Autoimmune endocrinopathies: An emerging complication of immune checkpoint inhibitors. Annual Review of Medicine. 2021;72:313–330. doi:10.1146/annurev-med-050219-034237.
Qi QY, Vettivel J, Solanki K, et al. The utility of magnetic resonance imaging for hypophysitis secondary to immune checkpoint inhibitor use. Clinical Endocrinology. 2025;102(6):699–705. doi:10.1111/cen.15240.
Patel N, Hirwa K, Gardner G, et al. Immune checkpoint inhibitor-induced hypophysitis: A specific disease of corticotrophs? Endocrine Connections. 2024;13(11):e240223. doi:10.1530/EC-24-0223.
Medical Disclaimer
This article is provided for educational and informational purposes and is not a substitute for professional medical diagnosis or treatment. Patients receiving immune checkpoint inhibitor therapy who develop headache, visual symptoms, severe fatigue, nausea or vomiting, dizziness, hypotension, or altered mental status should seek appropriate medical evaluation because endocrine immune-related adverse events, including adrenal insufficiency, can be clinically serious. Diagnosis and treatment decisions should be made by qualified healthcare professionals based on the individual's clinical findings, laboratory results, imaging studies, and overall medical condition.
© ScholarGen MediAI — Medical Imaging • Clinical AI • Healthcare Technology
Comments
Post a Comment