Background: Cyclical Cushings syndrome has been considered to be a rare clinical entity, characterised by periodic increases in cortisol levels followed by regression of the Cushings syndrome. The cycles of hypercortisolism may occur before the establishment of the diagnosis, rendering actual diagnosis difficult, or may occur after inadequate or ineffective treatment and affect disease management. The aim of this study was to investigate the prevalence of cyclicity of clinical symptoms and signs in patients with Cushings disease, and to identify the characteristic features of this idiosyncratic population.
Methods: Two hundred and two patients with biochemically confirmed Cushings disease, admitted from 1946 until 2001, were subjected to a retrospective case-note study. Cyclical disease was defined by the presence 1) intermittent signs and symptoms of Cushings syndrome with or without biochemical confirmation prior to presentation; and 2) variability in signs, symptoms and biochemical findings during their follow up.
Results: Fifty-eight (24%) patients had evidence of cyclical disease. The patients were diagnosed at a mean age of 37.5 (median: 36; range: 795) years and were followed-up for a mean period of 14.5 (median: 14; range: 052) years. Evidence of cyclic disease before diagnosis was present in 28 (45%) and after diagnosis in 32 (55%) of patients. Before diagnosis the first evidence of cyclicity was present at a mean period of 5.58 (median: 5; range: 023) years before the established diagnosis. In the female population cyclical disease was present in 27% (41/154) and in the male population in 35% (17/48). About 16 (8%) patients were under 18 years old at presentation and cyclic disease was present in 2 (12.5%).
Conclusions: The findings in this large population study reveal that cyclic disease is not a rare presentation of Cushings disease, and the physician should be alert to this possibility in making the diagnosis as well as after treatment in the follow-up period.