Pituitary and Stalk Lesions (Infundibulo-hypophysitis) Associated with Immunoglobulin G4-related Systemic Disease: an Emerging Clinical Entity

Abstract

Abstract. Inflammatory lesions of the pituitary gland are rarely encountered. Recently, the concept of immunoglobulin G4 (IgG4)-related systemic disease was proposed in Japan, and more than 20 cases have been reported as possibly associated with infundibulo-hypophysitis since 2000. We herein review such case reports in the published literature and in the abstracts of scientific meetings. Almost all cases involved middle-aged to elderly men presenting with various degrees of hypopituitarism and diabetes insipidus and demonstrating a thickened pituitary stalk and/or pituitary mass. These structures shrank remarkably in response to glucocorticoid therapy, even in a lower dose range similar to that prescribed as a replacement for adrenocortical insufficiency. Some of the anterior pituitary insufficiencies were also resolved by glucocorticoid administration. The presence of IgG4-related systemic disease and an elevated serum IgG4 level before glucocorticoid therapy were the main clues to a correct diagnosis of IgG4-related infundibulo-hypophysitis. Autoimmunity is suggested but not yet established to play a role in the pathogenesis for IgG4-related systemic disease. The fact that hypertrophic pachymeningitis and para-sinusitis accompanied some cases suggested that both sellar and parasellar structures are involved in the chronic inflammation. We therefore classify this disorder not as a variant form of primary autoimmune hypophysitis but as a secondary form of infundibulo-hypophysitis associated with IgG4-related systemic disease.

Immunoglobulin G4−Related Sclerosing Disease Mimicking Invasive Tumor in the Nasal Cavity and Paranasal Sinuses

“…[7][8][9] In the head and neck region, IgG4RSD commonly manifests as chronic sclerosing sialadenitis, chronic sclerosing dacryoadenitis, and lymphoplasmacytic hypophysitis. 1,10,11 IgG4RSD is considered to result from an imbalance in the regulatory immune reaction, 12 but the mechanisms are still unclear. IgG4RSD develops predominantly in males 13 and involves Ն2 sites in most patients, though some patients may have disease involving only 1 organ.…”

Hypertrophic Pachymeningitis and Tracheobronchial Stenosis in IgG4-related Disease: Case Presentation and Literature Review

“…Several cases of IgG4-related disease accompanied by hypophysitis as a CNS lesion have been reported (6,(13)(14)(15)(16)(17)(18)(19), but only four documented cases of IgG4-related pachymeningitis have been described to date (20)(21)(22)(23). Fortunately, all four case reports included histopathological data.…”

Lymphocytic Hypophysitis Accompanied by Aseptic Meningitis Mimics Subacute Meningoencephalitis

“…A diagnosis of LYH was made after the exclusion of secondary causes of hypophysitis. IgG4-related sclerosing disease is a systemic disease that is characterized by an extensive infiltration of IgG4-positive plasma cells and T-lymphocytes into various organs, such as the pancreas, bile duct, gallbladder, salivary gland, retroperitoneum, kidney, lung and prostate (17). Recently, a new disease entity, hypophysitis associated with an IgG4-related systemic disease such as multifocal fibrosclerosis, has been described (18).…”