Acta Neurochir DOI 10.1007/s00701-017-3288-8
CASE REPORT - BRAIN TUMORS
Intrachiasmatic abscess caused by IgG4-related hypophysitis Georgios F. Hadjigeorgiou 1 & Eva Løbner Lund 2 & Lars Poulsgaard 3 & Ulla Feldt-Rasmussen 4 & Åse Krogh Rasmussen 4 & Marianne Wegener 5 & Kåre Fugleholm 3
Received: 1 March 2017 / Accepted: 26 July 2017 # Springer-Verlag GmbH Austria 2017
Abstract Introduction Autoimmune hypophysitis is a rare disease of the pituitary, which may affect vision by inflammation and compression of the optic chiasm. However, intrachiasmatic abscess formation has not been previously reported. Methods In this study, we report a case of a 29-year-old female with bitemporal hemianopia due to a cystic intrasellar tumor. The patient underwent surgical decompression of the lesion, which was found to be an intrachiasmatic abscess. Results The histologic findings were consistent with IgG4 hypophysitis. Conclusion This rare clinical presentation suggests that in case of a disproportionate degree of visual impairment in relation to the size of the lesion, suspicion should lead to an intrachiasmatic lesion.
Keywords Abscess . Hypophysitis . IgG4 . Intrachiasmatic
* Georgios F. Hadjigeorgiou [email protected]
Background Hypophysitis is an infiltrative disease of the pituitary gland, with a predilection in women, especially in the postpartum period [3, 9]. Primary hypophysitis is usually classified as lymphocytic, granulomatous or xanthomatous, based on the histologic characteristics. However, rare variants of primary hypophysitis have recently been established such as IgG4related hypophysitis and necrotizing hypophysitis [4]. The pathogenesis is probably autoimmune, but with different pathologic features of the lymphocytic, granulomatous, xanthomatous, IgG4-related or necrotizing hypophysitis [3]. Lymphocytic adenohypophysitis is mediated by anti-pituitary antibodies against pituitary antigens exposed by the enlarged gland during pregnancy, combined with postpartum autoimmune exacerbation [11]. Magnetic resonance imaging (MRI) findings suggestive of hypophysitis include symmetric enlargement of the pituitary gland, a thickened stalk, a usually intact sellar floor and homogeneity of the pituitary mass, which enhance after gadolinium. Diffuse infiltration of the pituitary gland by inflammatory cells results in varying degrees of endocrine dysfunction, including diabetes insipidus. Other clinical manifestations of the disease include headache, general weakness and visual disturbance [8]. Primary hypophysitis is rare and has a tendency to recur. We report an intrachiasmatic abscess as a manifestation of recurrent Ig4related hypophysitis in a 29-year-old female. There are to our knowledge no previous reports of any type of intrachiasmatic abscess.
1
Department of Neurosurgery, Academic Hospital Munich-Bogenhausen, Technical University of Munich, Munich, Germany
2
Department of Pathology, University Hospital of Copenhagen, Copenhagen, Denmark
3
Department of Neurosurgery, University Hospital of Copenhagen, Copenhagen, Denmark
4
Department of Endocrinology, University Hospital of Copenhagen, Copenhagen, Denmark
Clinical presentation
5
Department of Neuro-opthalmology, University Hospital of Copenhagen, Copenhagen, Denmark
After steroid treatment of a biopsy-proven hypophysitis 4 years earlier, a 29-year-old female presented to the
Acta Neurochir
Department of Medical Endocrinology at a tertiary referral Pituitary Center because of retrobulbar pain and subjective worsening of her visual fields. The primary hypophysitis had left her with an upper bitemporal quadranopia and optic disc atrophy along with a deficiency of secretion of antidiuretic hormone (ADH), growth hormone (GH) and thyroid stimulating hormone (TSH). The current neuroophthalmologic examination revealed a subtle worsening of the temporal hemianopia of the right eye, but visual acuity was unchanged at 20/20 in both eyes. Ishihara color vision as well as pupillary reflexes was normal without any relative afferent pupillary defect (RAPD). The pituitary MRI demonstrated a small cystic intrasellar tumor below and in close contact with the right optic chiasm. A recurrence of the hypophysitis was suspected. The patient underwent treatment for a month with high-dose prednisolone but although her headache was alleviated, her visual disturbances persisted. A further MRI of the pituitary gland demonstrated no significant changes in comparison with the previous MRI. Since the MRI findings were unsuggestive of a surgical lesion, corticosteroid treatment was continued, and a new MRI was scheduled 2 weeks later. The new MRI scan revealed a further increase of the tumor. As the visual parameters were stable, conservative therapy was continued. During steroid tapering 2 months later, the patient experienced increasing visual impairment, especially in her right eye. The opthalmologic examination demonstrated progression of her visual field defects to an almost complete bitemporal hemianopia, worse on the right eye. Right visual acuity had dropped to 20/25 along with a slight
Fig. 1 MRI scan (coronal view) of the pituitary gland revealing a cystic mass that extends toward the right optic chiasm and optic nerve. Visual fields show a bitemporal hemianopia, worse on the right eye
Fig. 2 Preoperative MRI scan (sagittal view) of the cystic mass
dyschromatopsia (5 errors out of 17 plates on the Ishihara color vision test), and a right RAPD was seen. Left visual acuity and color vision were normal. She had a new MRI, which revealed further expansion of the cystic suprasellar formation extending toward the right side of the optic chiasm and right optic nerve (Figs. 1, 2). In view of the new imaging and opthalmologic findings, the decision was made to surgically decompress the optic nerves and chiasm. Since the cystic mass was located purely suprasellar with an extension to the right optic nerve, the preferred surgical route was through a right pterional approach. After splitting the sylvian fissure and opening of the opticocarotid cistern, a bulging enlargement of the chiasm was observed (Fig. 3). According to the intraoperative findings, the lesion seemed to be located intrachiasmatically. However, it could not be ruled out that the lesion has arisen from the pituitary stalk and stretched the chiasm over the top. Afterwards, the lesion was punctured with a thin 23-gauge
Fig. 3 Intraoperative image before the puncture of the enlarged chiasm
Acta Neurochir
Fig. 4 Intraoperative image after the aspiration of the intrachiasmatic cyst
Fig. 5 a H&E stain. The histology shows a lymphoplasmacytic infiltrate accompanied by varying numbers of macrophages, neutrophils and eosinophils. The adenohypophysial parenchyma shows variable destruction. b Immunostaining for IgG4 shows areas with more than 10 IgG4-positive cells/high-power field. Bars: 20 my
needle, and a small amount of pus was aspirated, whereafter the cyst collapsed (Fig. 4). Postoperatively, the patient complained of minor headaches and dizziness. The microbiologic examination for bacteria and fungi was negative. Blood analysis showed an elevated IgG4 (>135 mg/dl). The quantiferon test for tuberculosis and all the markers for rheumatic diseases (ACE, ANA, ANCA) were negative. The original biopsy showed adenohypophysis with a severe, diffuse, mixed inflammatory infiltrate, including T-cells, B-cells, plasma cells, neutrophil and eosinophil granulocytes and histiocytic cells. Special stains for TB (Ziehl-Nielsen) and fungi (PAS and Gomori-Trichrome) were negative. No bacterial infiltrates were found. The biopsy was re-evaluated at the time of the second operation, and immunostains for IgG4 and IgG were performed. The IgG4 staining showed areas with more than ten IgG4-positive plasma cells per ten high power fields, and based on this finding, it was concluded that the criteria for IgG4-related disease were fulfilled. The postoperative MRI and ophthalmologic examination 6 weeks postoperatively showed a significant improvement (Fig. 5). Visual acuity was 20/20 in both eyes, color vision was normal, and visual fields showed reduction of the bitemporal hemianopia, but the right RAPD remained. A 2year follow-up after surgery showed a stable opthalmologic condition with a subtotal hemianopsia at the right eye and an upper quadrant anopsia at the left eye. The patient remains in treatment with mycophenolatmofetil 1000 mg three times a day, and the prednisolone dose has been reduced to 10 mg daily Fig. 6.
Fig. 6 Postoperative MRI scan and visual fields on the bottom of the image showing significant improvement
Acta Neurochir
Discussion The clinical presentations of primary hypophysitis are variable, ranging from hypopituitarism and diabetes insipidus to visual impairment, cranial nerve palsies and headache. Headache is considered the result of distortion of the dura and diaphragma sellae by the expanding sellar mass. Visual abnormalities include visual field defects, classically bitemporal hemianopia, decreased visual acuity and dyschromatopsia secondary to compression of the chiasm and the optic nerves by the expanding pituitary mass. Partial or complete suppression of the anterior pituitary hormones produces the classic signs of hypoadrenalism, hypothyroidism and hypogonadism. Diabetes insipidus is due to a lack of ADH, attributed to direct immune destruction of the posterior lobe [3]. Diagnosis of hypophysitis based on MRI findings can be quite challenging. However, the symmetry of pituitary enhancement, lack of erosive changes of the sellar floor and intense enhancement of the pituitary gland after gadolinium can be diagnostic in the proper clinical background [3, 12]. Despite typical clinical and imaging findings, some primary hypophysitis cases may still go undiagnosed or require a long-term treatment. In our case, the management of the relapse and final treatment of the patient lasted more than 5 months. Initially the cystic tumor was small and close to the optic chiasm, but did not compress the optic pathways. An inflammatory activity in the cystic process (hypophysitis reactivation) with a secondary inflammatory activity in the chiasm was suspected to give rise to the visual disturbances, which is why she was initially treated with steroids. However, the last MRI revealed a cystic intrachiasmatic formation, which led to further worsening of the visual fields and required surgical intervention. This manifestation of the hypophysitis must be extremely rare. Direct invasion of the chiasm by the inflammatory process is our best explanation for the development of the intrachiasmatic abscess. IgG4-related hypophysitis is characterized by an abundance of IgG4-producing plasma cells and was first reported in 2004 [10]. Since then, several cases have been reported, and the diagnosis is presumably underestimated [1, 2, 5–7]. This case demonstrates a new presentation of IgG4-related hypophysitis. To the best of our knowledge, no previous case of an intrachiasmatic abscess caused by IgG4-related hypophysitis has been described.
Conclusion Hypophysitis is a rare but increasingly recognized pituitary disorder. The entirely intrachiasmatic relapse of the disease in our case has not previously been reported, but should be considered when a mismatch between the size of a structural
lesion and the degree of visual impairment occurs. In addition, the intrachiasmatic abscess adds a new presentation of IgG4 hypophysitis. Compliance with ethical standards Author disclosure statement No competing financial interests exist. Details of previous presentations The content of the manuscript, all or in part, has not been published and is not being considered for publication in any form. Funding No funding was received for this research. Conflict of interest All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript. Ethical approval All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Informed consent Informed consent was obtained from all individual participants included in the study.
References 1.
2.
3. 4. 5.
6.
7.
Batista RL, Ramos LS, Cescato VA, Musolino NR, Borba CG, Silva GO, Moreno LH, Cunha Neto MB (2015) Thickened pituitary stalk associated with a mass in the sphenoidal sinus: an alarm to suspect Hypophysitis by immunoglobulin G4? Int Arch Otorhinolaryngol 19:273–276 Bondo H, Iguchi G, Fukuoka H, Taniguchi M, Yamamoto M, Matsumoto R, Suda K, Nishizawa H, Takahashi M, Kohmura E, Takahashi Y (2014) The prevalence of IgG4-related hypophysitis in 170 consecutive patients with hypopituitaruism and/or central diabetes insipidus and review of the literature. Europ J Endocrinol 170: 161–172 Caturegli P, Newschaffer C, Olivi A, Pomper MG, Burger PC, Rose NR (2005) Autoimmune hypophysitis. Endocr Rev 26:599–614 Fukuoka H (2015) Hypophisitis. Endocrinol Metab Clin N Am 44(1):143–149 Harano Y, Honda K, Akiyama Y, Kotajima L, Arioka H (2015) A case of IgG4-related hypophysitis presented with hypopituitarism and diabetes insipidus. Clinical Medicine Insights: Case Reports 8: 23–25 Leporati P, Landek-Salgado MA, Lupi I, Chiovato L, Caturegli P (2011) IgG4-related hypophysitis: a new addition to the hypophysitis spectrum. J Clin Endocrinol Metab 96:1971–1980 Ngaosuwan K, Trongwongsa T, Shuangshoti S (2015) Clinical course of IgG4-related hypophysitis presenting with focal seizure and relapsing lymphocytic hypophysitis. BMC Endocr Disord 15: 64
Acta Neurochir 8.
9.
Thodou E, Asa SL, Kontogeorgos G, Kovacs K, Horvath E, Ezzat S (1995) Clinical case seminar: lymphocytic hypophysitis: clinicopathological findings. J Clin Endocrinol Metab 80:2302–2311 Park SM, Bae JC, Joung JY, Cho YY, Kim TH, Jin SM, Suh S, Hur KY, Kim KW (2014) Clinical characteristics, management, and outcome of 22 cases of primary hypophysitis. Endocrinol Metab (Seoul) 29(4):470–478
10.
11. 12.
Van der Vliet HJ, Perenboom RM (2004) Multiple pseudotumors in IgG4-associated multifocal systemic fibrosis. Am Int Med 141: 896–897 Weetman AP (2010) Immunity, thyroid function and pregnancy: molecular mechanisms. Nat Rev Endocrinol 6(6):311–318 Yang GQ, Lu ZH, Gu WJ, Du J, Guo QH, Wang XL, Ba JM, Dou JT, Mu YM, Lu JM (2011) Recurrent autoimmune hypophysitis successfully treated with glucocorticoids plus azathioprine: a report of three cases. Endocr J 58(8):675–683
CASE REPORT - BRAIN TUMORS
Intrachiasmatic abscess caused by IgG4-related hypophysitis Georgios F. Hadjigeorgiou 1 & Eva Løbner Lund 2 & Lars Poulsgaard 3 & Ulla Feldt-Rasmussen 4 & Åse Krogh Rasmussen 4 & Marianne Wegener 5 & Kåre Fugleholm 3
Received: 1 March 2017 / Accepted: 26 July 2017 # Springer-Verlag GmbH Austria 2017
Abstract Introduction Autoimmune hypophysitis is a rare disease of the pituitary, which may affect vision by inflammation and compression of the optic chiasm. However, intrachiasmatic abscess formation has not been previously reported. Methods In this study, we report a case of a 29-year-old female with bitemporal hemianopia due to a cystic intrasellar tumor. The patient underwent surgical decompression of the lesion, which was found to be an intrachiasmatic abscess. Results The histologic findings were consistent with IgG4 hypophysitis. Conclusion This rare clinical presentation suggests that in case of a disproportionate degree of visual impairment in relation to the size of the lesion, suspicion should lead to an intrachiasmatic lesion.
Keywords Abscess . Hypophysitis . IgG4 . Intrachiasmatic
* Georgios F. Hadjigeorgiou [email protected]
Background Hypophysitis is an infiltrative disease of the pituitary gland, with a predilection in women, especially in the postpartum period [3, 9]. Primary hypophysitis is usually classified as lymphocytic, granulomatous or xanthomatous, based on the histologic characteristics. However, rare variants of primary hypophysitis have recently been established such as IgG4related hypophysitis and necrotizing hypophysitis [4]. The pathogenesis is probably autoimmune, but with different pathologic features of the lymphocytic, granulomatous, xanthomatous, IgG4-related or necrotizing hypophysitis [3]. Lymphocytic adenohypophysitis is mediated by anti-pituitary antibodies against pituitary antigens exposed by the enlarged gland during pregnancy, combined with postpartum autoimmune exacerbation [11]. Magnetic resonance imaging (MRI) findings suggestive of hypophysitis include symmetric enlargement of the pituitary gland, a thickened stalk, a usually intact sellar floor and homogeneity of the pituitary mass, which enhance after gadolinium. Diffuse infiltration of the pituitary gland by inflammatory cells results in varying degrees of endocrine dysfunction, including diabetes insipidus. Other clinical manifestations of the disease include headache, general weakness and visual disturbance [8]. Primary hypophysitis is rare and has a tendency to recur. We report an intrachiasmatic abscess as a manifestation of recurrent Ig4related hypophysitis in a 29-year-old female. There are to our knowledge no previous reports of any type of intrachiasmatic abscess.
1
Department of Neurosurgery, Academic Hospital Munich-Bogenhausen, Technical University of Munich, Munich, Germany
2
Department of Pathology, University Hospital of Copenhagen, Copenhagen, Denmark
3
Department of Neurosurgery, University Hospital of Copenhagen, Copenhagen, Denmark
4
Department of Endocrinology, University Hospital of Copenhagen, Copenhagen, Denmark
Clinical presentation
5
Department of Neuro-opthalmology, University Hospital of Copenhagen, Copenhagen, Denmark
After steroid treatment of a biopsy-proven hypophysitis 4 years earlier, a 29-year-old female presented to the
Acta Neurochir
Department of Medical Endocrinology at a tertiary referral Pituitary Center because of retrobulbar pain and subjective worsening of her visual fields. The primary hypophysitis had left her with an upper bitemporal quadranopia and optic disc atrophy along with a deficiency of secretion of antidiuretic hormone (ADH), growth hormone (GH) and thyroid stimulating hormone (TSH). The current neuroophthalmologic examination revealed a subtle worsening of the temporal hemianopia of the right eye, but visual acuity was unchanged at 20/20 in both eyes. Ishihara color vision as well as pupillary reflexes was normal without any relative afferent pupillary defect (RAPD). The pituitary MRI demonstrated a small cystic intrasellar tumor below and in close contact with the right optic chiasm. A recurrence of the hypophysitis was suspected. The patient underwent treatment for a month with high-dose prednisolone but although her headache was alleviated, her visual disturbances persisted. A further MRI of the pituitary gland demonstrated no significant changes in comparison with the previous MRI. Since the MRI findings were unsuggestive of a surgical lesion, corticosteroid treatment was continued, and a new MRI was scheduled 2 weeks later. The new MRI scan revealed a further increase of the tumor. As the visual parameters were stable, conservative therapy was continued. During steroid tapering 2 months later, the patient experienced increasing visual impairment, especially in her right eye. The opthalmologic examination demonstrated progression of her visual field defects to an almost complete bitemporal hemianopia, worse on the right eye. Right visual acuity had dropped to 20/25 along with a slight
Fig. 1 MRI scan (coronal view) of the pituitary gland revealing a cystic mass that extends toward the right optic chiasm and optic nerve. Visual fields show a bitemporal hemianopia, worse on the right eye
Fig. 2 Preoperative MRI scan (sagittal view) of the cystic mass
dyschromatopsia (5 errors out of 17 plates on the Ishihara color vision test), and a right RAPD was seen. Left visual acuity and color vision were normal. She had a new MRI, which revealed further expansion of the cystic suprasellar formation extending toward the right side of the optic chiasm and right optic nerve (Figs. 1, 2). In view of the new imaging and opthalmologic findings, the decision was made to surgically decompress the optic nerves and chiasm. Since the cystic mass was located purely suprasellar with an extension to the right optic nerve, the preferred surgical route was through a right pterional approach. After splitting the sylvian fissure and opening of the opticocarotid cistern, a bulging enlargement of the chiasm was observed (Fig. 3). According to the intraoperative findings, the lesion seemed to be located intrachiasmatically. However, it could not be ruled out that the lesion has arisen from the pituitary stalk and stretched the chiasm over the top. Afterwards, the lesion was punctured with a thin 23-gauge
Fig. 3 Intraoperative image before the puncture of the enlarged chiasm
Acta Neurochir
Fig. 4 Intraoperative image after the aspiration of the intrachiasmatic cyst
Fig. 5 a H&E stain. The histology shows a lymphoplasmacytic infiltrate accompanied by varying numbers of macrophages, neutrophils and eosinophils. The adenohypophysial parenchyma shows variable destruction. b Immunostaining for IgG4 shows areas with more than 10 IgG4-positive cells/high-power field. Bars: 20 my
needle, and a small amount of pus was aspirated, whereafter the cyst collapsed (Fig. 4). Postoperatively, the patient complained of minor headaches and dizziness. The microbiologic examination for bacteria and fungi was negative. Blood analysis showed an elevated IgG4 (>135 mg/dl). The quantiferon test for tuberculosis and all the markers for rheumatic diseases (ACE, ANA, ANCA) were negative. The original biopsy showed adenohypophysis with a severe, diffuse, mixed inflammatory infiltrate, including T-cells, B-cells, plasma cells, neutrophil and eosinophil granulocytes and histiocytic cells. Special stains for TB (Ziehl-Nielsen) and fungi (PAS and Gomori-Trichrome) were negative. No bacterial infiltrates were found. The biopsy was re-evaluated at the time of the second operation, and immunostains for IgG4 and IgG were performed. The IgG4 staining showed areas with more than ten IgG4-positive plasma cells per ten high power fields, and based on this finding, it was concluded that the criteria for IgG4-related disease were fulfilled. The postoperative MRI and ophthalmologic examination 6 weeks postoperatively showed a significant improvement (Fig. 5). Visual acuity was 20/20 in both eyes, color vision was normal, and visual fields showed reduction of the bitemporal hemianopia, but the right RAPD remained. A 2year follow-up after surgery showed a stable opthalmologic condition with a subtotal hemianopsia at the right eye and an upper quadrant anopsia at the left eye. The patient remains in treatment with mycophenolatmofetil 1000 mg three times a day, and the prednisolone dose has been reduced to 10 mg daily Fig. 6.
Fig. 6 Postoperative MRI scan and visual fields on the bottom of the image showing significant improvement
Acta Neurochir
Discussion The clinical presentations of primary hypophysitis are variable, ranging from hypopituitarism and diabetes insipidus to visual impairment, cranial nerve palsies and headache. Headache is considered the result of distortion of the dura and diaphragma sellae by the expanding sellar mass. Visual abnormalities include visual field defects, classically bitemporal hemianopia, decreased visual acuity and dyschromatopsia secondary to compression of the chiasm and the optic nerves by the expanding pituitary mass. Partial or complete suppression of the anterior pituitary hormones produces the classic signs of hypoadrenalism, hypothyroidism and hypogonadism. Diabetes insipidus is due to a lack of ADH, attributed to direct immune destruction of the posterior lobe [3]. Diagnosis of hypophysitis based on MRI findings can be quite challenging. However, the symmetry of pituitary enhancement, lack of erosive changes of the sellar floor and intense enhancement of the pituitary gland after gadolinium can be diagnostic in the proper clinical background [3, 12]. Despite typical clinical and imaging findings, some primary hypophysitis cases may still go undiagnosed or require a long-term treatment. In our case, the management of the relapse and final treatment of the patient lasted more than 5 months. Initially the cystic tumor was small and close to the optic chiasm, but did not compress the optic pathways. An inflammatory activity in the cystic process (hypophysitis reactivation) with a secondary inflammatory activity in the chiasm was suspected to give rise to the visual disturbances, which is why she was initially treated with steroids. However, the last MRI revealed a cystic intrachiasmatic formation, which led to further worsening of the visual fields and required surgical intervention. This manifestation of the hypophysitis must be extremely rare. Direct invasion of the chiasm by the inflammatory process is our best explanation for the development of the intrachiasmatic abscess. IgG4-related hypophysitis is characterized by an abundance of IgG4-producing plasma cells and was first reported in 2004 [10]. Since then, several cases have been reported, and the diagnosis is presumably underestimated [1, 2, 5–7]. This case demonstrates a new presentation of IgG4-related hypophysitis. To the best of our knowledge, no previous case of an intrachiasmatic abscess caused by IgG4-related hypophysitis has been described.
Conclusion Hypophysitis is a rare but increasingly recognized pituitary disorder. The entirely intrachiasmatic relapse of the disease in our case has not previously been reported, but should be considered when a mismatch between the size of a structural
lesion and the degree of visual impairment occurs. In addition, the intrachiasmatic abscess adds a new presentation of IgG4 hypophysitis. Compliance with ethical standards Author disclosure statement No competing financial interests exist. Details of previous presentations The content of the manuscript, all or in part, has not been published and is not being considered for publication in any form. Funding No funding was received for this research. Conflict of interest All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript. Ethical approval All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Informed consent Informed consent was obtained from all individual participants included in the study.
References 1.
2.
3. 4. 5.
6.
7.
Batista RL, Ramos LS, Cescato VA, Musolino NR, Borba CG, Silva GO, Moreno LH, Cunha Neto MB (2015) Thickened pituitary stalk associated with a mass in the sphenoidal sinus: an alarm to suspect Hypophysitis by immunoglobulin G4? Int Arch Otorhinolaryngol 19:273–276 Bondo H, Iguchi G, Fukuoka H, Taniguchi M, Yamamoto M, Matsumoto R, Suda K, Nishizawa H, Takahashi M, Kohmura E, Takahashi Y (2014) The prevalence of IgG4-related hypophysitis in 170 consecutive patients with hypopituitaruism and/or central diabetes insipidus and review of the literature. Europ J Endocrinol 170: 161–172 Caturegli P, Newschaffer C, Olivi A, Pomper MG, Burger PC, Rose NR (2005) Autoimmune hypophysitis. Endocr Rev 26:599–614 Fukuoka H (2015) Hypophisitis. Endocrinol Metab Clin N Am 44(1):143–149 Harano Y, Honda K, Akiyama Y, Kotajima L, Arioka H (2015) A case of IgG4-related hypophysitis presented with hypopituitarism and diabetes insipidus. Clinical Medicine Insights: Case Reports 8: 23–25 Leporati P, Landek-Salgado MA, Lupi I, Chiovato L, Caturegli P (2011) IgG4-related hypophysitis: a new addition to the hypophysitis spectrum. J Clin Endocrinol Metab 96:1971–1980 Ngaosuwan K, Trongwongsa T, Shuangshoti S (2015) Clinical course of IgG4-related hypophysitis presenting with focal seizure and relapsing lymphocytic hypophysitis. BMC Endocr Disord 15: 64
Acta Neurochir 8.
9.
Thodou E, Asa SL, Kontogeorgos G, Kovacs K, Horvath E, Ezzat S (1995) Clinical case seminar: lymphocytic hypophysitis: clinicopathological findings. J Clin Endocrinol Metab 80:2302–2311 Park SM, Bae JC, Joung JY, Cho YY, Kim TH, Jin SM, Suh S, Hur KY, Kim KW (2014) Clinical characteristics, management, and outcome of 22 cases of primary hypophysitis. Endocrinol Metab (Seoul) 29(4):470–478
10.
11. 12.
Van der Vliet HJ, Perenboom RM (2004) Multiple pseudotumors in IgG4-associated multifocal systemic fibrosis. Am Int Med 141: 896–897 Weetman AP (2010) Immunity, thyroid function and pregnancy: molecular mechanisms. Nat Rev Endocrinol 6(6):311–318 Yang GQ, Lu ZH, Gu WJ, Du J, Guo QH, Wang XL, Ba JM, Dou JT, Mu YM, Lu JM (2011) Recurrent autoimmune hypophysitis successfully treated with glucocorticoids plus azathioprine: a report of three cases. Endocr J 58(8):675–683
