A Unique Case of Central Hypopituitarism and Central Diabetes Insipidus Caused By Diffuse Large B-Cell Lymphoma

ABSTRACT Objective: To present the case of a 39-year-old male admitted to the hospital with diabetes insipidus as a sequela of a previously undiagnosed diffuse large B-cell lymphoma. This case is unique, as the patient's disease was determined to be an infiltrative malignancy affecting the pituitary infundibular stalk, resulting in multifocal pituitary dysfunction. Methods: Case report. Results: Initially presenting with gastrointestinal bleed, later discovered to be from tumor infiltration of gastric vessels, diagnosis of lymphoma was made when gastrectomy became necessary for hemostasis. Subsequent hypernatremia on basic laboratory studies led to further investigation and revealed central diabetes insipidus. Magnetic resonance imaging of the pituitary was performed, showing thickening of the infundibular stalk. Additional endocrine evaluation revealed central hypothyroidism and central adrenal insufficiency. Conclusion: Radiologic findings of thickened pituitary infundibulum can support the diagnosis of central diabetes insipidus when additional symptoms are present. Central diabetes insipidus due to lymphomatous infundibular stalk infiltration is an uncommon presentation of endocrine deficiency as well as malignancy; this case demonstrates the management of a critically ill patient with central hypopituitarism due to diffuse B-cell lymphoma. Abbreviations: ADH = antidiuretic hormone; DDAVP = desmopressin; DI = diabetes insipidus; IV = intravenous; MRI = magnetic resonance imaging