Archives of Endocrinology and Metabolism (Apr 2019)

The 4Ds of ectopic ACTH syndrome: diagnostic dilemmas of a difficult disease

  • Marcelo Vieira-Corrêa,
  • Débora Moroto,
  • Giovanna Carpentieri,
  • Igor Veras,
  • Claudio E. Kater

DOI
https://doi.org/10.20945/2359-3997000000129
Journal volume & issue
Vol. 63, no. 2
pp. 175 – 181

Abstract

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SUMMARY Cushing’s syndrome (CS) is an uncommon condition that leads to high morbidity and mortality. The majority of endogenous CS is caused by excessive ACTH secretion, mainly due to a pituitary tumor – the so-called Cushing’s disease (CD) – followed by ectopic ACTH syndrome (EAS), an extra-pituitary tumor that produces ACTH; adrenal causes of CS are even rarer. Several methods are used to differentiate the two main etiologies: specific laboratory tests and imaging procedures, and bilateral inferior petrosal sinus sampling (BIPSS) for ACTH determination; however, identification of the source of ACTH overproduction is often a challenge. We report the case of a 28-year-old woman with clinical and laboratory findings consistent with ACTH-dependent CS. All tests were mostly definite, but several confounding factors provoked an extended delay in identifying the origin of ACTH secretion, prompting a worsening of her clinical condition, with difficulty controlling hyperglycemia, hypokalemia, and hypertension. During this period, clinical treatment was decisive, and measurement of morning salivary cortisol was a differential for monitoring cortisol levels. This report shows that clinical reasoning, experience and use of recent methods of nuclear medicine were decisive for the elucidation of the case.