A case of lymphocytic infundibuloneurohypophysitis showing diabetes insipidus followed by anterior hypopituitarism associated with thrombasthenia.

We report a case of a 42-year old male patient with diabetes insipidus followed by anterior hypopituitarism associated with thrombasthenia. The patient had been diagnosed with thrombasthenia since the age of 19. He was admitted and diagnosed as diabetes insipidus in 1995. Although T1-weighted image of magnetic resonance imaging (MRI) showed empty sella and partial pituitary stalk hypertrophy, the anterior pituitary functions were normal at that time. Three years later, he was re-admitted after an episode of general malaise and impotence in 1998. Endocrinological studies revealed adrenal insufficiency, hypothyroidism and hypogonadism. T1-weighted image of MRI demonstrated the thickening of pituitary stalk and neurohypophysis. Analysis of anti-pituitary antibodies by immunoblotting identified a major band at 61.5 kDa. The diabetes insipidus was controlled by desmopressin acetate and the shrinkage of pituitary stalk was seen after hormonal replacement therapy including glucocorticoid and thyroid hormone. We suggested that this case represented lymphocytic infundibuloneurohypophysitis, in which a chronic inflammatory process occurred in infundibulum and/or neurohypophysis and that hypopituitarism developed possibly due to damage to the pituitary portal vessels caused by a thickened pituitary stalk, although a pituitary biopsy was not done because of the risk of bleeding in thrombasthenia. The pituitary autoantibodies in sera from patients with hypopituitarism may be helpful to characterize the patient with lymphocytic hypophysitis.