MECHANISMS IN ENDOCRINOLOGY: Hypophysitis: diagnosis and treatment

Sellar Tumors

Sellar region lesions include a broad range of benign and malignant neoplastic as well as non-neoplastic entities, many of which are newly described or have recently revised nomenclature. In contrast to other intracranial sites, imaging features are relatively less specific, and the need for histopathological diagnosis is of paramount importance. This review will describe pituitary adenomas, inflammatory lesions, and tumors unique to the region (craniopharyngioma) as well as tumors which may occur in but are not exclusively localized to the sellar location (schwannoma, metastasis, etc.).

Lymphocytic infundibuloneurohypophysitis with positive anti-rabphilin-3A antibodies nine years post-onset of central diabetes insipidus

Childhood-onset lymphocytic infundibuloneurohypophysitis (LINH) due to infiltration of autoimmune lymphocyte in the neurohypophysis is rarely reported. Its definitive diagnosis requires a pituitary biopsy, which is an invasive procedure. Recently, anti-rabphilin-3A antibody has been reported as a potential diagnostic marker for LINH in adults; however, only a few cases have been reported in children. Here, we present a case of childhood-onset LINH in a 10-yr-old boy identified as anti-rabphilin-3A antibody positive during chronic phase, 9 yr post-onset of central diabetes insipidus (CDI). T1-weighted magnetic resonance imaging (MRI) revealed pituitary stalk thickening and absence of posterior pituitary bright signal spot, and the hormonal responses of the adenohypophysis to GHRH, TRH, CRH, and LHRH revealed no abnormalities during the first admission. MRI at 5 mo post-onset indicated reduced stalk swelling; however, replacement treatment with intranasal desmopressin was continued to counter unimproved CDI. Additionally, GH replacement therapy was also initiated to counter its deficiency. Pituitary re-enlargement was not observed in the subsequent routine MRI, and no increase was observed in the levels of tumor markers during follow-up, which was considered clinically consistent with LINH. Our case study suggests that anti-rabphilin-3A antibody may be considered as a useful diagnostic marker for LINH in children.

Xanthomatous Hypophysitis: A Case Report and Comprehensive Literature Review

PURPOSE

Xanthomatous hypophysitis (XHP) is an extremely rare form of primary hypophysitis for which there is a lack of clinical experience. A comprehensive understanding of its clinical characteristics, diagnosis and treatment is needed.

METHODS

Here, we report a case study and conduct a systematic review of XHP. Thirty-six cases were included, and their clinical manifestations, endocrine assessment, imaging features, treatment and follow-up data were collected and analyzed.

RESULTS

The mean age at diagnosis was 39.1 years, and females were predominant (75.0%). The most common symptom was headache (68.6%), and 66.7% of female patients presented menstrual disorders. The most common pituitary dysfunction was growth hormone (GH) deficiency. More than half of patients exhibited central diabetes insipidus (CDI). The majority of patients had an imaging presentation of a cystic lesion with peripheral enhancement. Pituitary stalk thickening was observed in half of the patients. Total lesion resection was achieved in 57.1% of cases. The recurrence rate after partial resection and biopsy was significantly higher than that after total lesion resection (57.1% vs. 0.0%, P = 0.0147). The most common pituitary hormone abnormalities to resolve after surgery were hyperprolactinemia (100.0%) and GH deficiency (91.7%). The typical pathological feature was inflammatory infiltration of foamy histiocytes, which showed positivity for CD68.

CONCLUSION

Diagnosis of XHP is difficult when relying on clinical symptoms and imaging features. Therefore, surgical histopathology is necessary. Based on the available evidence, total lesion resection is recommended for treatment. However, the long-term prognosis for this rare disease remains unclear.

Autoimmune diabetes insipidus

Once central diabetes insipidus (CDI) has been diagnosed, every effort should be made to reveal its underlying cause. Autoimmune CDI should be considered in the differential diagnosis of idiopathic CDI and also of mass lesions of the sella region. An autoimmune etiology of CDI was first suggested in 1983 by the detection of autoantibodies to hypothalamic vasopressin-producing cells (AVPcAb) in adults and also in children with the disease, using the indirect immunofluorescence test. The major autoantigen for autoimmune CDI has now been recognized as rabphilin-3A, a protein of secretory vesicles of the neurohypophyseal system. The detection of autoantibodies to rabphilin-3A by Western blotting or of AVPcAb provides strong evidence for the diagnosis of autoimmune CDI. Autoimmune CDI is recognized mostly in patients who had also been diagnosed with endocrine autoimmune disorders. The radiological and morphological correlate with autoimmune DI is lymphocytic infundibuloneurohypophysitis (LINH) as detected by magnetic resonance imaging and biopsies that show massive infiltration of the posterior pituitary and the infundibulum with lymphocytes and some plasma cells, and fibrosis in the later stages of the disease. LINH may be associated with lymphocytic anterior hypophysitis. Both may either appear spontaneously or on treatment with immune checkpoint inhibitors.

Magnetic resonance imaging of the hypothalamo-pituitary region

The diagnosis and management of mass lesions in the sellar and parasellar areas remain challenging. When approaching patients with possible sellar or hypothalamic masses, it is important not only to focus on imaging but also detect possible pituitary hormone deficits or excess, in order to establish an appropriate diagnosis and initiate treatment. The imaging modalities used to characterize hypothalamic and pituitary lesions have significantly evolved over the course of the past several years. Computed tomography (CT) and CT angiography play a major role in detecting various sellar lesions, especially in patients who have contraindications to magnetic resonance imaging (MRI) and can also yield important information for surgical planning. However, MRI has become the gold standard for the detection and characterization of hypothalamic and pituitary tumors, infections, cystic, or vascular lesions. Indeed, the imaging characteristics of hypothalamic and sellar lesions can help narrow down the differential diagnosis preoperatively. In addition, MRI can help establish the relationship of mass lesions to surrounding structures. A pituitary MRI examination should be obtained if there is concern for mass effect (including visual loss, ophthalmoplegia, headache) or if there is clinical suspicion and laboratory evidence of either hypopituitarism or pituitary hormone excess. The information obtained from MRI images also provides us with assistance in planning surgery. Using intraoperative MRI can be very helpful in assessing the adequacy of tumor resection. In addition, MRI images yield reliable data that allow for noninvasive monitoring of patients postoperatively.

Prospective Evaluation of Incidental Pituitary Imaging Findings in the Sella Turcica

Purpose

Reported rates of incidentally discovered pituitary sellar lesions vary widely, at least in part because of the inadvertent inclusion of patients with a history suspicious for a pituitary disorder. We prospectively evaluated the incidence of truly incidental sellar findings detected on imaging at a large academic medical center.

Methods

Deidentified data were extracted from the electronic medical record of adults who underwent diagnostic computed tomography (CT) or magnetic resonance imaging (MRI) over a 1-year period for any cause unrelated to known or suspected pituitary disorder both in inpatient and outpatient settings. Patients with International Classification of Diseases, Ninth Revision, (ICD-9) and Tenth Revision (ICD-10) codes indicative of a sellar lesion and those with symptoms suggestive of sellar/parasellar mass effects were excluded.

Results

Of 9572 scans performed during the 1-year study period, 3840 met the inclusion criteria to comprise the study cohort; 13 were manually excluded because of findings or symptoms of sellar masses not otherwise captured. The overwhelming majority of evaluable images (n = 3782) showed no sellar lesions. Truly incidental sellar findings were detected in 45 (1.2%), most commonly among inpatients (P < .001). Partially empty sella and empty sella were the most frequent findings, and were twice as likely to be detected on MRI vs CT. All other incidentally discovered lesions, including one microadenoma and one macroadenoma, were detected only by MRI.

Conclusion

Frequency of incidental sellar lesions in patients with no known or suspected history of pituitary disorder is low. Given the small likelihood of aggressive behavior in these lesions, the clinical significance of truly incidentally discovered sellar lesions should not be overestimated.

Anti-pituitary antibodies as a marker of autoimmunity in pituitary glands

Autoimmunity contributes to the pathogenesis of hypophysitis, a chronic inflammatory disease in the pituitary gland. Although primary hypophysitis is rare, the number of pituitary dysfunction cases induced by immune checkpoint inhibitors (ICIs) is increasing. While it is difficult to prove the involvement of autoimmunity in the pituitary glands, circulating anti-pituitary antibodies (APAs) can be measured by indirect immunofluorescence and used as a surrogate marker of pituitary autoimmunity. APAs are present in several pituitary diseases, including lymphocytic adenohypophysitis, lymphocytic infundibulo-neurohypophysitis (LINH), IgG4-related hypophysitis, and pituitary dysfunction induced by ICIs. Mass spectrometry analysis of antigens targeted by APAs clarified rabphilin-3A as an autoantigen in LINH. This demonstrates that APAs can be applied as a probe to identify novel autoantigens in other pituitary autoimmune diseases, including pituitary dysfunction induced by ICIs, which can aid in biomarker discovery.

Reversible primary adrenal insufficiency related to anti-programmed cell-death 1 protein active immunotherapy: Insight into an unforeseen outcome of a rare immune-related adverse event

The immune checkpoint inhibitors (ICPi) revolutionize the cancer therapeutics, though not being devoid of toxicity. The immune-related primary adrenal insufficiency (PAI) is a rare, yet potentially life-threatening, adverse event, posing diagnostic and therapeutic challenges. We report the first case of reversible PAI related to nivolumab (programmed cell-death 1 protein inhibitor) in a 42-year-old male with metastatic rectal adenocarcinoma. PAI manifested as profound fatigue, disorientation, hypotension, hyperpigmentation of palmar creases, and hyponatremia without hyperkalemia 16 weeks after initiation of nivolumab. Due to impending adrenal crisis, intravenous stress doses of hydrocortisone and hydration with normal saline were initiated. When the state of patient was stabilized, PAI was confirmed through 250 μg Synacthen test 24 h after temporary cessation of hydrocortisone. Hydrocortisone was fixed at maintenance dose, while mineralocorticoid substitution was not required. PAI was ascribed to nivolumab based on history, physical examination, and laboratory work-up with emphasis on positivity of anti-21-hydroxylase antibodies and exclusion of other causes of PAI by normal imaging of adrenal glands on computed tomography (CT). Reevaluation of adrenal function during follow up demonstrated complete recovery. A review of literature concerning the immune-related PAI indicated that the complete recovery of adrenal function, the normal CT imaging, and the positivity of anti-21-hydroxylase antibodies observed in our patient are exceptional findings of immune-related PAI. Finally, heightened suspicion of immune-related PAI in case of hyponatremia without hyperkalemia and constant vigilance for diagnosis of rare, but real, reversibility of immune-related PAI are of paramount importance.

Management of endocrine immune-related adverse events of immune checkpoint inhibitors: an updated review

Immune checkpoint inhibitors (ICIs) belong to a new group of anticancer drugs targeting T-cell proteins involved in the activation of immune response toward malignancies. Their introduction into clinical practice was a milestone in modern cancer treatment. However, the significant advantage of ICIs over conventional chemotherapy in terms of therapeutic efficacy is accompanied by new challenges related to specific side effects. ICI-induced immune system activation could lead to the loss of self-tolerance, presenting as autoimmune inflammation and dysfunction of various tissues and organs. Thus, the typical side effects of ICIs include immune-related adverse events (irAEs), among which endocrine irAEs, affecting numerous endocrine glands, have been commonly recognized. This review aimed to outline the current knowledge regarding ICI-induced endocrine disorders from a clinical perspective. We present updated information on the incidence and clinical development of ICI-induced endocrinopathies, including the most frequent thyroiditis and hypophysitis, the rarely observed insulin-dependent diabetes mellitus and primary adrenal insufficiency, and the recently described cases of hypoparathyroidism and lipodystrophy. Practical guidelines for monitoring, diagnosis, and treatment of ICI-related endocrine toxicities are also offered. Rising awareness of endocrine irAEs among oncologists, endocrinologists, and other health professionals caring for patients receiving ICIs could contribute to better safety and efficacy. As immunotherapy becomes widespread and approved for new types of malignancies, increased incidences of endocrine irAEs are expected in the future.

Central diabetes insipidus caused by a pituitary stalk germinoma resembling infundibuloneurohypophysitis

We report the case of a pituitary stalk germinoma initially misdiagnosed and treated as infundibuloneurohypophysitis (INH). A 27-year-old man presented with a 1-year history of polydipsia, polyuria, nycturia consistent with central diabetes insipidus and a hyperintense pituitary stalk lesion on MRI. A possible INH diagnosis was considered, after excluding other pathologies. Lesion biopsy was discarded at that time on the ground of a small target and the high risk of added morbidity. Oral desmopressin led to initial symptoms resolution but, in the following months, an anterior panhypopituitarism developed, in spite of appropriate treatment and, by that time, the brain MRI also revealed lesion growth, which prompted a biopsy recommendation. The pathology analysis revealed a germinoma. After chemotherapy and radiotherapy, there was complete disappearance of the pituitary lesion, but the panhypopituitarism persisted. In conclusion, this case highlights the importance and difficulty of precise diagnosis in the initial assessment of pituitary stalk lesions and the need for close monitoring of treatment response. Diagnostic reassessment and biopsy in atypical cases is the only path to achieve the correct diagnosis and treatment.

MRI Findings of Immune Checkpoint Inhibitor-Induced Hypophysitis: Possible Association with Fibrosis

BACKGROUND AND PURPOSE

Hypophysitis is one of the well-known adverse effects of immune checkpoint inhibitors. Immune checkpoint inhibitor-induced hypophysitis frequently causes irreversible hypopituitarism, which requires long-term hormone replacement. Despite the high frequency and clinical significance, characteristic MR imaging findings of immune checkpoint inhibitor-induced hypophysitis have not been established. In the present study, we aimed to review and extract the MR imaging features of immune checkpoint inhibitor-induced hypophysitis.

MATERIALS AND METHODS

This retrospective international multicenter study comprised 20 patients with melanoma who were being treated with immune checkpoint inhibitors and clinically diagnosed with immune checkpoint inhibitor-induced hypophysitis. Three radiologists evaluated the following MR imaging findings: enlargement of the pituitary gland and stalk; homogeneity of enhancement of the pituitary gland; presence/absence of a well-defined poorly enhanced area and, if present, its location, shape, and signal intensity in T2WI; and enhancement pattern in contrast-enhanced dynamic MR imaging. Clinical symptoms and hormone levels were also recorded.

RESULTS

Enlargement of the pituitary gland and stalk was observed in 12 and 20 patients, respectively. Nineteen patients showed poorly enhanced lesions (geographic hypoenhancing lesions) in the anterior lobe, and 11 of these lesions showed hypointensity on T2WI. Thyrotropin deficiency and corticotropin deficiency were observed in 19/20 and 12/17 patients, respectively, which persisted in 12/19 and 10/12 patients, respectively, throughout the study period.

CONCLUSIONS

Pituitary geographic hypoenhancing lesions in the anterior lobe of the pituitary gland are characteristic and frequent MR imaging findings of immune checkpoint inhibitor-induced hypophysitis. They reflect fibrosis and are useful in distinguishing immune checkpoint inhibitor-induced hypophysitis from other types of hypophysitis/tumors.

Infiltrative lymphocytic hypophysitis successfully treated with rituximab and mycophenolate mofetil

SUMMARY

Lymphocytic hypophysitis is a rare neuroendocrine disease characterised by an autoimmune inflammatory disorder of the pituitary gland. We report a 50-year-old woman who presented with headaches and bilateral sixth cranial nerve palsies. MRI of the pituitary revealed extensive fibrosis involving the sellar and extending into both cavernous sinuses causing bilateral occlusion of the internal carotid arteries (ICA). Transphenoidal biopsy confirmed the diagnosis of infiltrative fibrotic lymphocytic hypophysitis. Symptoms resolved with high dose of oral steroids but relapsed on tapering, requiring several treatments of i.v. pulse steroids over 8 months. Rituximab combined with mycophenolate mofetil was required to achieve long-term symptom relief. Serial MRI pituitary imaging showed stabilisation of her disease without reduction in sellar mass or regression of ICA occlusion. The patient's brain remained perfused solely by her posterior circulation. This case demonstrates an unusual presentation of a rare disease and highlights a successful steroid-sparing regimen in a refractory setting.

LEARNING POINTS

Lymphocytic hypophysitis is a rare inflammatory disorder of the pituitary gland. In exceptional cases, there is infiltration of the cavernous sinus with subsequent occlusion of the internal carotid arteries. First-line treatment of lymphocytic hypophysitis is high-dose glucocorticoids. Relapse after tapering or discontinuation is common and its use is limited by long-term adverse effects. There is a paucity of data for treatment of refractory lymphocytic hypophysitis. Goals of treatment should include improvement in symptoms, correction of hormonal insufficiencies, reduction in lesion size and prevention of recurrence. Steroid-sparing immunosuppressive drugs such as rituximab and mycophenolate mofetil have been successful in case reports. This therapeutic combination represents a viable alternative treatment for refractory disease.

Emergency management of immune-related toxicity

PURPOSE OF REVIEW

Emergency presentations in patients treated with immune checkpoint inhibitors (ICIs) are a clinical challenge. Clinicians need to be vigilant in diagnosing and treating immune-mediated toxicities. In this review, we consider the approach to managing an acutely unwell patient being treated with ICIs presenting as an emergency.

RECENT FINDINGS

A minority of acutely unwell patients treated with ICIs will have an immune-mediated toxicity. Early recognition and intervention in those with immune-mediated toxicity can reduce the duration and severity of the complications. The use of early immunosuppressive agents along corticosteroid therapy may improve outcomes in patients with life-threatening immune-mediated toxicity.

SUMMARY

Individualized management of immune-mediated toxicities is a key challenge for emergency oncology services; this has become part of routine cancer care.

Autoimmune hypophysitis and viral infection in a pregnant woman: a challengeable case

The aim of this study is to report a challengeable and rare case of autoimmune hypophysitis possibly induced by viral infections. A young pregnant female developed optic neuropathy due to enlarged sellar mass responsible for hypopituitarism. Investigations exclude neoplasia and systemic diseases. High level of sedimentation rate and magnetic resonance imaging (MRI) findings supported the diagnosis of autoimmune hypophysitis. The patient reported a history of bronchitis treated with antibiotics and corticosteroids and positive serologies for hepatitis B antigen (Hbs antigen), herpes simplex 1 and rubella. Final examination showed complete recovery of visual function and sellar archnoidocele after antiviral treatment and mild dose of corticosteroids.

Endocrine adverse events related with immune checkpoint inhibitors: an update for clinicians

Designated as scientific breakthrough of current decade, immune checkpoint inhibitors attenuate the cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and the programmed cell death 1 (PD-1)/ligand 1 (PD-L1) pathways, depriving cancer cells of a key strategy of evasion from immunosurveillance. The reinvigoration of immune response translates into clinical success, inevitably entwined with a novel constellation of immune-related adverse events. The present review dissects the endocrine immune-related adverse events, emphasizing their unique profile featured by unpredictable onset, irreversibility, nonspecific symptoms, wide clinical spectrum and sophisticated diagnostic work-up. Guidelines advocate individualized decision-making process guided by clinicians' judgement. Future perspective should be governed by five principles - prevention, anticipation, detection, treatment, monitoring - aiming to gain the optimal profit diminishing immunotoxicity.

Granulomatous hypophysitis causing compression of the internal carotid arteries reversible with azathioprine and rituximab treatment

INTRODUCTION

Compression of the internal carotid artery (ICA) in the cavernous sinus area is a rare event and is mostly associated with pituitary adenomas and meningiomas. Other causes of ICA compression are less well known. We present a rare case of granulomatous hypophysitis causing compression of the ICA, which was treated successfully with immune-suppressive agents.

METHODS

The electronic database MEDLINE (PubMed) was searched systematically and other cases with ICA compression were identified and analyzed.

RESULTS

A female patient with a history of two previous transsphenoidal operations for suspected pituitary adenoma and post-operative complete pituitary insufficiency presented with severe headaches, nausea, fatigue, and diplopia. Pituitary MRI scan suggested relapse of the pituitary lesion with atypical bilateral infiltration of cavernous sinuses and compression of ICAs. After histological reevaluation of her previous pituitary operations, granulomatous hypophysitis was diagnosed. Treatment was started with high doses of prednisolone. With decreasing doses of prednisolone, symptoms recurred, and azathioprine was started, followed by administration of rituximab resulting in clinical recovery and regression of ICA compression. Literature analysis disclosed 36 case reports with ICA compression in the cavernous sinus region (12 pituitary adenoma, 6 meningioma, 7 hypophysitis, 5 other tumors, and 4 other etiologies). Two cases of hypophysitis recovered completely; five cases improved only partly.

CONCLUSION

In the case of ICA compression, clinical signs, onset of symptoms, radiological findings and pituitary insufficiencies should be thoroughly evaluated, and hypophysitis should be considered as a possible cause. In our patient, treatment with azathioprine and, finally, rituximab was successful.

Co-Occurrence of Craniopharyngioma and IgG4-Related Hypophysitis: An Epiphenomenon or a Mere Coincidence?

BACKGROUND

Craniopharyngiomas are sellar-suprasellar tumors that commonly present in children, with nonspecific symptoms of increased intracranial pressure, visual disturbances, and pituitary insufficiencies. Rarely has secondary hypophysitis (lymphocytic and xanthogranulomatous) been reported in association with craniopharyngioma.

CASE DESCRIPTION

We have reported the case of a 16-year-old boy who had presented with gradually progressive diminution of vision in the right eye, intermittent headache, deceleration in growth velocity, and the lack of development of secondary sexual characteristics. Imaging revealed a sellar-suprasellar cystic lesion (3.8 × 3.1 × 3.5 cm) with calcifications. Laboratory tests revealed hypothyroidism, hypocortisolism, hypogonadism, and growth hormone deficiency. Craniopharyngioma was provisionally diagnosed. He underwent pterional craniotomy and gross total excision of the lesion. The excised tissue showed features of adamantinomatous craniopharyngioma, with a dense lymphoplasmacytic infiltrate and fibrosis involving the pituitary and dura mater. The lymphocytes were CD20-positive, and the plasma cells stained positive for IgG4 (50-60 IgG4-positive plasma cells/high power field). Consequently, the possibility of IgG4-related hypophysitis was considered in our patient. His serum IgG4 level was not elevated. Systemic involvement by IgG4-related disease was thoroughly ruled out. Fluorodeoxyglucose positron emission tomography/computed tomography did not show any clinically significant hypermetabolism anywhere in the body. At the 3-month follow-up examination, his headache had resolved. However, he had not regained vision in his right eye. Repeat imaging studies showed no residual tumor tissue.

CONCLUSIONS

The present case might represent the first ever report, to the best of our knowledge, of secondary IgG4-related hypophysitis due to craniopharyngioma, or it might, perhaps, be a chance association of these 2 entirely different disease entities.

Intracranial Germinoma Masquerading as Secondary Granulomatous Hypophysitis: A Case Report and Review of Literature

Germinomas are highly immunogenic tumors eliciting a strong peri-tumoral immune response that can spillover into the surrounding healthy tissues. This phenomenon can also occur in intracranial germinomas, manifesting as secondary hypophysitis. Herein, we report a case of 12-year-old-girl presenting with polyuria and polydispsia. She had central diabetes insipidus (CDI) and panhypopituitarism. Imaging revealed a sellar-suprasellar mass with infundibular stalk thickening. Transphenoidal biopsy revealed epithelioid granulomas with immunostaining negative for germinomatous cells. Other causes of hypophysitis were ruled out. Accordingly, she was diagnosed as primary granulomatous hypophysitis and treated with high-dose corticosteroids. Three years later she again presented with headache, vomiting and diminution of vision. Imaging showed a heterogeneous, solid-cystic peripheral rim-enhancing lesion at the same location with involvement of hypothalamus, ependyma and pineal gland. Cerebrospinal fluid beta-human chorionic gonadotropin was markedly elevated, confirming the diagnosis of an intracranial germ cell tumor. She was started on chemotherapy; however, she succumbed to febrile neutropenia. We performed a literature search and found 18 anecdotal cases of secondary hypophysitis associated with intracranial germinomas. There was a slight male preponderance (male:female 5:4). Two-thirds of the cases were below 18 years of age. Polyuria was the most common presenting manifestation (83%). CDI and panhypopituitarism were seen in 89 and 78% cases, respectively. Imaging evidence of pituitary stalk thickening was seen in 12 cases (67%), while pituitary enlargement and/or sellar mass were reported in 11 cases (61%). Pineal involvement was extremely rare, being reported in only 1 case, implying the predilection of suprasellar (rather than pineal) germinomas in causing secondary hypophysitis. Histologically, 82% had lymphocytic hypophysitis, while 18% had granulomatous hypophysitis. Initially, the diagnosis of germinoma was missed in 60% of the cases who were wrongly treated with corticosteroids. To conclude, physicians should make it a dictum that all children and adolescents presenting with CDI and pituitary stalk thickening should be rigorously screened for an underlying intracranial germinoma before labeling them as primary hypophysitis.

Hypophysitis (Including IgG4 and Immunotherapy)

Hypophysitis is characterized by inflammation of the pituitary gland that can be primary (PH) or secondary (SH) to other diseases or following drug administration. It may also be classified according to anatomical and histopathological criteria, leading to variable degrees of hypopituitarism and/or compressive symptoms to nearby structures. There has recently been an increase in the number of hypophysitis cases, raising the interest on the spectrum of its pathogenesis, clinical, biochemical/endocrinological, and imaging features. However, the use of conventional biomarkers, including currently utilized pituitary autoantibodies, has relatively limited diagnostic accuracy. Lymphocytic hypophysitis (LH) is the commonest cause of PH, whereas IgG4-related hypophysitis is increasingly being recognized. Histiocytosis and granulomatous diseases are the most frequent causes of SH, although infections and lymphoma have also been reported. The increasing use of immune checkpoint inhibitors in oncology is associated with a high incidence of hypophysitis, providing further understanding of its pathogenesis. Hypophysitis can occur silently and be easily missed, potentially leading to substantial morbidity or mortality due to adrenal insufficiency, requiring a high index of clinical suspicion and timely initiation of appropriate treatment. In most cases of LH or drug-induced hypophysitis, active surveillance along with replacement of established hormonal deficiencies is needed. In the presence of compressive and/or evolving symptoms, treatment with glucocorticoids either alone or in combination with other immunosuppressive agents can be used. Surgical decompression is reserved for nonresponsive cases with threatened vital structures. Timely diagnosis and intervention are important to minimize disease-related morbidity and mortality. We aimed to review current concepts and recent developments in the pathogenesis, diagnosis, and management of hypophysitis.

Immune check point inhibitors-induced hypophysitis: a retrospective analysis of the French Pharmacovigilance database

Immune control point (ICI) inhibitors represent a significant advance in the management and survival of cancers such as melanoma or non-small cell bronchial carcinoma. However, they induce unusual side effects, such as hypophysitis, which are rarely described elsewhere. This nationwide retrospective study describes the characteristics of hypophysitis reported in the French pharmacovigilance database (FPVD). We requested for all cases of ICI-related hypophysitis registered in the FPVD before May 2018. An endocrinologist and a pharmacologist reviewed all cases. About 94 pituitary cases were selected, involving 49 females and 45 men. Ipilimumab alone or in combination was the most represented ICI (56%). Most cases (61%) were grade 3 severity and the majority (90%) were corticotropic deficiency cases. Cases with thyroid and/or gonadotropic involvement were 21% and 1% respectively. Five patients (8%) had panhypopituitarism. Pituitary MRI, when performed, was in favor of hypophysitis in 50%. No patient recovered his previous hormonal function. The mean time of onset was significantly shorter with ipilimumab than other ICIs. ICI-related hypophysitis generate deficits that do not spontaneously recover, even at a distance from the event, unlike thyroiditis. Patients must then benefit from long-term coordinated onco-endocrinological management, adapted to their own specific deficits.

Hypophysitis: An update on the novel forms, diagnosis and management of disorders of pituitary inflammation

Hypophysitis is a heterogeneous condition that leads to inflammation of the sella and/or suprasellar region, potentially resulting in hormonal deficiencies and/or mass effects. A preponderance of hypophysitis subtypes have an underlying autoimmune aetiology. The overall incidence and prevalence of hypophysitis has dramatically increased over the past decade, mainly due to increased awareness of the condition in the medical community, improvements in imaging techniques, and a rise in the occurrence of certain forms of hypophysitis such as IgG4 hypophysitis (IgG4Hy) and immune checkpoint inhibitor induced hypophysitis (ICIHy). The clinical presentation varies from an asymptomatic condition to a fatal disease often as a result of electrolyte abnormalities due to glucocorticoid deficiency in the context of adrenal crisis from central adrenal insufficiency. Milder forms of hypophysitis are treated with replacement of deficient hormones while more acute presentations with mass effects require glucocorticoid therapy, immunosuppressive therapy or surgery. Timely diagnosis and interventions are keys to prevention of the lethal complications of this disease. In this review, we provide an update on the recent advances in the field of pituitary autoimmunity, with an emphasis on autoimmune hypophysitis and novel forms of hypophysitis such as anti-PIT1 hypophysitis, IgG4Hy and ICIHy.

Other Pituitary Conditions and Pregnancy

Diagnosis of lymphocytic hypophysitis occurring in the peripartum period is based on clinical and neuroradiological data and does not require a biopsy. Its course is generally spontaneously favorable in terms of mass effect but may require the administration of corticosteroids or even transsphenoidal resection. The course of pituitary deficiencies is highly variable; some cases recover over time, whereas others persist indefinitely. Sheehan syndrome is very rare in developed countries. Because agalactia and amenorrhea are often neglected, the diagnosis is generally delayed. Diabetes insipidus occurring in late pregnancy is caused by the increased placental production of vasopressinase and disappears after delivery.

Primary hypophysitis: Experience of a Single Tertiary Center

PURPOSE

The authors review the clinical outcomes of patients with primary hypophysitis (PH).

METHODS

Patients with PH who were followed up between 2007 and 2018 at our clinic were evaluated. Clinical, endocrinologic, pathologic, radiologic findings and treatment modalities were assessed.

RESULTS

Seventeen patients with PH were assessed. The median follow-up was 24 (range, 6-84) months. Histologic confirmation was available in 8 patients (6 lymphocytic hypophysitis, 1 lymphocytic-granulomatous hypophysitis, 1 xanthomatous hypophysitis). None of the cases were diagnosed after pregnancy. Two patients had an autoimmune disease. The most commonly seen symptom was headache. The most common anterior pituitary deficiencies were hypocortisolemia and hypothyroidism. The radiologic findings of the patients at the time of diagnosis revealed various results including space-occupying lesion (41.2%), loss of posterior hypophysis bright spot (47.1%), pituitary stalk thickening (41.2%), uniform contrast enhancement (17.6%), partially empty sella (11.8%), optic chiasm compression (11.8%). The most frequent initial treatment modality was observation. Ten patients who were followed up conservatively had no endocrinologic deterioration; additional treatment was not needed in 8 of these 10 patients. The second most frequent initial treatment modality was pituitary surgery. Five patients received steroid treatment. We found serious adverse effects during steroid treatment in 3 of 5 (60%) patients; unilateral avascular necrosis of the femoral head (n=2), diabetes mellitus(n=1).

CONCLUSION

Correctly diagnosing PH and giving appropriate treatment is challenging. It is unclear whether active treatment with steroids improves clinical outcomes. The serious adverse effects of steroids are also taken into account. Observation, surgery and/or radiotherapy can be appropriate treatment modalities for selected patients.