PMON84 A Unique Case of Diabetes Insipidus Revealing Hodgkin's lymphoma

INTRODUCTION: While diabetes insipidus rarely presents as a symptom of non-Hodgkin's lymphoma, it is very rarely a revealing symptom of Hodgkin's lymphoma. We present a case of this unique association. CASE PRESENTATION: We report a case of a 25-year-old previously healthy male with no significant past medical history who presented with complaints of polydipsia, polyuria, and nocturia. A water deprivation test confirmed central diabetes insipidus. He started therapy with oral desmopressin and had clinical improvement. Magnetic resonance imaging (MRI) of his head showed thickened infundibulum and a lack of posterior pituitary bright spot, consistent with infundibulo-neurohypophysitis. There were no obvious masses within the anterior or posterior lobe, nor were suprasellar soft tissue masses noted. Diabetes mellitus (DM), autoimmune diseases, and infectious diseases were excluded. A chest x-ray revealed a superior mediastinal mass and a CT scan confirmed multiple mediastinal lymphadenopathies. A biopsy of pre-tracheal lymph node revealed nodular sclerosing Hodgkin's lymphoma. The patient received six cycles of chemotherapy with Adriamycin, Bleomycin, Vinblastine and Dacarbazine (ABVD) and achieved a complete remission. A follow up MRI head scan showed a decreasing in the thickness of infundibulum along with non-visualization of the posterior pituitary bright spot. Finally, his symptoms resolved with DDAVP therapy. CONCLUSIONS: Diabetes insipidus involving the pituitary gland of Hodgkin's lymphoma is an extremely rare presentation of endocrine deficiency and malignancy. The literature describes only a few such cases. Clinicians should be aware diabetes insipidus might rarely present as a symptom of Hodgkin's lymphoma without obvious metastatic involvement of the neurohypophysial system. Continuing to report anecdotal experiences in managing similar complex scenarios is essential and remains the only reference for clinicians who handle patients with a similar presentation. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.