PSEUDOCARCINOID SYNDROME-ASSOCIATED WITH HYPOGONADISM AND RESPONSE TOTESTOSTERONE THERAPY

Objective: To characterize a disorder of episodes of flushing and incr eased levels of 5-hydroxyindoleacetic acid (5-HIAA) in men with second ary hypogonadism who respond to testosterone therapy, Material and Met hods: We present detailed case reports of three male patients who had flushing, secondary hypogonadism, and increased urinary 5-HIAA levels and describe their clinical and laboratory features before and after t reatment with testosterone, In addition, six male patients with hypogo nadism (three with primary and three with secondary hypogonadism) with out flushing were assessed, Results: The three patients with flushing and secondary hypogonadism (serum total testosterone 5.45 +/- 0.63 nmo l/L, free testosterone 89.3 +/- 7.0 pmol/L, follicle-stimulating hormo ne 3.85 +/- 0.58 IU/L, and luteinizing hormone 4.41 +/- 0.98 IU/L) had increased urinary 5-HIAA levels (98.5 +/- 12.2 mu mol/24 h) but norma l blood serotonin levels (9.66 +/- 1.58 mu mol/L). During a pentagastr in-calcium stimulation test, serum calcitonin and blood serotonin valu es were normal in patients with secondary hypogonadism and flushing, D etailed investigation showed no evidence of a carcinoid tumor, Urinary 5-HIAA levels became normal (16.6 +/- 1.73 mu mol/24 h) after treatme nt with testosterone, When testosterone therapy was discontinued in tw o patients, flushing and increased urinary 5-HIAA levels recurred, Fur thermore, flushing and the elevated urinary 5-HIAA values resolved whe n testosterone treatment was reinitiated, The six patients with hypogo nadism without flushing had normal urinary 5-HIAA levels (14.9 +/- 3.3 1 mu mol/24 h), Conclusion: Male patients with flushing and increased urinary 5-HIAA levels should undergo assessment for hypogonadism after screening for carcinoid tumor, If hypogonadism is diagnosed, resoluti on of flushing and normalization of 5-HIAA may be achieved with testos terone treatment, We suggest that pseudocarcinoid syndrome associated with hypogonadism be the descriptive label used for this combination o f clinical features.