A Case of IgG4-Related Infundibulo-Hypophysitis Presented as Pituitary Incidentaloma

Case Report

Austin Endocrinol Diabetes Case Rep. 2016; 1(1): 1002.

A Case of IgG4-Related Infundibulo-Hypophysitis Presented as Pituitary Incidentaloma

Wat WZM¹*, Cheng Y² and Kho BCS¹

¹Department of Medicine, Pamela Youde Nethersole Eastern Hospital, Hong Kong

²Department of Clinical Pathology, Pamela Youde Nethersole Eastern Hospital, Hong Kong

*Corresponding author: WAT Zee Man, Department of Medicine, Pamela Youde Nethersole Eastern Hospital, 3 Lok Man Road, Chai Wan, Hong Kong

Received: May 25, 2016; Accepted: July 13, 2016; Published: July 15, 2016

Abstract

IgG4-related infundibulo-hypophysitis is very rare and is usually presented with hypopituitarism, central diabetes insipidus or pseudotumour with mass effect. We reported a case presented as a large pituitary incidentaloma with height of 17mm in the MRI orbits of a 45 year-old male complaining of bilateral chronic upper eyelid swelling and generalised lymphadenopathy. His upper eye lid biopsy showed reactive lymphocytic infiltrates and lymph node biopsy reactive follicular hyperplasia. The pituitary mass, lymphadenopathy and eye signs dramatically responded to a therapeutic trial of prednisolone. His serum IgG4 level was later found significantly elevated and retrospective IgG and IgG4 immunohistochemistry study in previous cervical lymph node and nasopharyngeal biopsies confirmed the diagnosis of IgG4-related disease. His pituitary incidentaloma is likely IgG4-related infundibulo-hypophysitis. Repeat MRI after two months’ of steroid treatment showed the pituitary lesion reduced to a 7mm stalk nodule. Serial MRI showed that the stalk nodule remained static in size with low dose maintenance steroid.

Keywords: Pituitary mass; IgG4 related disease; Infundibulo-hypophysitis; Hypophysitis

Abbreviations

CT: Computed Tomography; MRI: Magnetic Resonance Imaging; IgG4: Immunoglobulin G4; NR: Normal Range; ESR: Erythrocyte Sedimentation Rate; CRP: C-Reactive Protein; ANA: Anti-Nuclear Antibodies; C3: Complement 3; LH: Luteinizing Hormone; FSH: Follicle Stimulating Hormone; TSH: Thyroid-Stimulating Hormone; HE: Haematoxylin Eosin

Case Presentation

The patient was first presented in April 1999, at the age of 45 years, with 2 years’ history of cervical lymphadenopathy and bilateral swollen upper eyelids. Biopsy of the cervical lymph node in March 2000 reported reactive follicular hyperplasia. Blood tests revealed only mild lymphocytosis of 4.81x 109/L (NR 0.6-3.4) and mild eosinophilia 0.84 x109/L (NR 0-0.7). Other blood tests including ESR, CRP, ANA pattern, C3, Rheumatoid factors were all normal. His symptoms did not respond to antibiotics.

He later defaulted follow up and returned in 2003 due to persistent symptoms. While the CT orbits in May 2003 showed bilateral prominent lacrimal glands and swollen extra-ocular muscles, his left lacrimal gland biopsy in January 2005 was unremarkable. However, his follow up MRI (1.5 Tesla) orbits in November 2005 incidentally revealed a large homogenously contrast enhanced pituitary mass of 17mm in height, moderately impressing on the optic chiasm (Figure1). His visual field by confrontation was full. He did not have any symptoms suggestive of hypopituitarism or diabetes insidipus. His blood tests in December 2005 showed mild hypogonadotrophic hypogonadism with serum total testosterone level of 5.4 nmol/L (NR 10-35), LH 3.9 IU/L (NR 1-12) and FSH 4.8 IU/L (NR 1-12). Other hormonal axes were normal with serum level of prolactin 344mU/L (NR 38-555), 10am cortisol 242nmol/L (NR 123-645), thyroxine 11.5pmol/L (NR 9.1-23.8) and TSH 1.44mIU/L (NR 0.32-5). Inpatient monitoring of the urine output and osmolarity revealed no diabetes insipidus. His immunoglobulin pattern showed significantly raised serum IgG level of 35.6g/L (NR 6.94-16.18g/L), but serum electrophoresis revealed no monoclonal band and urine no Bence Jones protein.