Syndrome of inappropriate secretion of antidiuretic hormone as an initial sign of primary central nervous system lymphomas in the hypothalamus.

BACKGROUND: Primary central nervous system lymphoma (PCNSL) rarely originates in the hypothalamus. Hypothalamic PCNSL can present with various symptoms specific to dysfunction of the hypothalamus, including consciousness disturbance, cognitive impairment, hypopituitarism, and diabetes insipidus (DI). However, it remains unclear whether syndrome of inappropriate secretion of antidiuretic hormone (SIADH) can present as an initial sign of hypothalamic PCNSL. METHODS: Ninety-nine patients with PCNSL were diagnosed between January 2006 and December 2020 at our institutes. The initial symptoms and signs, hypothalamic-pituitary functions, serum sodium (Na) value, Karnofsky Performance Status (KPS) score on admission, and duration from onset to diagnosis were retrospectively investigated from the medical charts. RESULTS: Eight and 91 patients had hypothalamic PCNSL (hypothalamic group) and PCNSL located in other regions (control group), respectively. Patients' pathological diagnoses were diffuse large B-cell lymphoma (97 patients) and intravascular lymphoma (two patients). Six patients presented with hyponatremia derived from SIADH or suspected SIADH, and one presented with DI. Statistically significant differences between the hypothalamic and control groups were detected only in the preoperative serum Na values and KPS scores. CONCLUSION: SIADH can be an initial presentation of hypothalamic PCNSL. Early detection of hypothalamic PCNSL from SIADH may lead to proper management and improved prognosis.

Radiological and endocrinological evaluations with grading of hypothalamic perifocal edema caused by craniopharyngiomas.

INTRODUCTION: Hypophysial and hypothalamic dysfunction caused by craniopharyngioma is a serious problem despite the progress of surgical approaches and techniques. Perifocal edema induced by craniopharyngioma could be speculated as a potential factor resulting in pre- and post-operative hypophysial and hypothalamic dysfunction, as well as, their anatomical involvement. METHODS: Medical records of 54 patients with craniopharyngioma were retrospectively reviewed. The edema was characterized by a hyperintense area in magnetic resonance imaging, being classified into no edema (group A), only adjacent to the tumor (group B), and extending to the internal capsule or the optic tract (group C). Age, sex, tumor diameter, presence of cyst, hydrocephalus, intracranial pressure (ICP) elevation, visual function impairment, hypopituitarism, diabetes insipidus, memory disturbance, and obesity were investigated. RESULTS: The occurrence rate of edema was found more frequently in adults (73.7%) than in children (25.0%). The peritumoral edema grading system had an excellent correlation with the degree of hypothalamic involvement graded by the Puget's system. Pre-operative ICP elevation was significantly detected in group C when compared with the other groups. In adults patients, group C was significantly associated with the occurrence of hydrocephalus both in pre- and post-operatively. Pre- and post-operative hypothalamic dysfunction, including diabetes insipidus, memory disturbance, and obesity, were highest in group C. CONCLUSION: Hypothalamic dysfunctions greatly influence the quality of daily living following craniopharyngioma surgery. The grading of perifocal edema's extension could be a new index suggesting pre- and post-operative hypothalamic dysfunction caused by craniopharyngioma in addition to their anatomical involvement.