Primary hypothalamic lymphoma with panhypopituitarism presenting as stiff-man syndrome.

We report an unusual case of primary hypothalamic lymphoma with hypopituitarism presenting as Stiff-man syndrome (SMS). A 64-year-old man was hospitalized due to a 3-week history of general weakness, anorexia, vomiting, weight loss, and muscle pain and spasms precipitated by motion and tactile stimuli resulting in muscle stiffness and difficulty in mobility. Physical examination revealed normal sensorimotor function and reflexes, except for bitemporal visual field defect. Routine laboratory and gastrointestinal examinations provided no remarkable clues. Endocrine assessment revealed low levels of morning cortisol, thyroxine, and anterior pituitary hormones but an increase in prolactin level. The patient's muscle pain and stiffness improved dramatically within 2 days after hydrocortisone therapy and thyroxine replacement. Magnetic resonance imaging (MRI) of the brain confirmed an 18-mm enhancing hypothalamic tumor with optic chiasm involvement, which proved to be a B-cell lymphoma. The results of the extensive studies for systemic lymphoma were negative, suggesting a primary hypothalamic lymphoma. The tumor regressed completely and was invisible on MRI scan after adjuvant radiotherapy. The patient's condition was satisfactory and there was no recurrence of SMS during the 2-year follow-up period. This case demonstrated that primary hypothalamic lymphoma complicated with adrenal insufficiency may manifest as SMS. Early diagnosis and prompt intervention can lead to a favorable outcome and reduce morbidity.

The relationship between morning serum cortisol and the short ACTH test in the evaluation of adrenal insufficiency.

BACKGROUND: Morning serum cortisol examinations and short corticotropin (ACTH) tests are popular screening tests for unstressed patients suspected of having adrenal insufficiency. However, the correlation between morning serum cortisol and the peak cortisol response in the short ACTH test after intravenous injection of ACTH has not been studied before. This retrospective study examined the relationship among the mean basal morning cortisol level, the single random morning cortisol level and the peak cortisol level in the short ACTH test in evaluation of adrenal insufficiency. METHODS: In this retrospective study, we examined the relationship among the mean basal morning cortisol level and the peak cortisol level stimulated by intravenous injection of 250 microg synthetic ACTH in 106 unstressed patients with proven or suspected hypothalamic-pituitary-adrenal disease. Plasma cortisol levels were determined by radioimmunoassay. The correlation of the basal morning cortisol to the short ACTH test was determined by linear regression analysis. The ACTH test was analyzed using the receiver operating characteristic (ROC) curve method, and the cut-off points for various sensitivity and specificity were calculated. RESULTS: The mean basal is highly correlated to peak cortisol response in the ACTH test (r = 0.7724, p < 0.0001). Iatrogenic Cushing's syndrome, caused by ingestion of herbs with illegal steroid additives, was the most common cause (60%) of adrenal insufficiency in the 52 patients with subnormal result. A mean basal morning serum cortisol of > or = 300 nmol/L excluded the possibility of adrenal insufficiency, and a level of < 110 nmol/L suggested adrenal insufficiency. A mean basal cortisol level of > or = 234 nmol/L predicted a normal cortisol response in the ACTH test with optimal sensitivity (80.6%) and specificity (91.4%). CONCLUSIONS: The mean morning cortisol level is a cost-effective screening test in predicting the results of the ACTH test. A mean morning cortisol level > or = 300 nmol/L in suspicious cases of adrenal insufficiency which are not due to acute central etiologies excludes the possibility of subnormal cortisol response to ACTH; whereas a level < 110 nmol/L is likely to have subnormal cortisol response to ACTH. The short ACTH test or insulin tolerance test should be performed in patients with a morning cortisol level 300 nmol/L or with clinical symptoms highly suggestive of adrenal insufficiency.