Lymphocytic infundibulo-neurohypophysitis and infundibulo-panhypophysitis regarded as lymphocytic hypophysitis variant.

Lymphocytic infundibulo-neurohypophysitis (LINH) was first reported by Saito et al. and Imura et al. as a cause of idiopathic central diabetes insipidus. Magnetic resonance (MR) imaging with a contrast medium demonstrates thickening of the pituitary stalk, enlargement of the neurohypophysis, or both with homogeneous enhancement. Histological examination reveals a posterior pituitary that is heavily infiltrated by lymphocytes with occasional plasma cells and other inflammatory cells. In early reports of the disorder, the lesion seemed to be limited to the neurohypophysis, but the present review showed cases with a combination of hypopituitarism and diabetes insipidus. Some of them showed partial hypopituitarism. The so-called lymphocytic infundibulo-panhypophysitis (LIPH) is now regarded as a lymphocytic hypophysitis variant. LINH and LIPH are essentially self-limited. In typical cases, conservative care with steroids and hormone replacement is recommended. Surgical intervention should be avoided because the natural course of the disorder may be self-limited. Pathophysiology of the disorder is still unknown. The unique clinical manifestations of the disorder are discussed and reviewed here.