Abstract
Ectopic ACTH production causes 10% of Cushing’s syndromes. The diagnostic workup is
difficult, can last more than 6 months (> 50% of cases), and the underlying tumour
is still frequently not located (12%). Carcinoid tumours of the appendix are frequent
and are revealed in 0.3% of patients undergoing routine appendectomy. However, neuroendocrine
tumours of the appendix with ACTH production are an extremely rare entity.
Here we report the case of a female patient with clinically overt Cushing’s syndrome
due to ectopic ACTH-production from a carcinoid tumour of the appendix. During the
diagnostic workup, repeated endocrine tests, multiple different imaging modalities
and frequent and lengthy hospitalisations were necessary. Wrongly, even a neurosurgical
pituitary exploration was performed. After 12 months from the initial admission, the
tumour was finally detected by an 18F-fluoro-L-dihydroxyphenylalanine (18FDOPA PET) and an appendectomy followed by right hemicolectomy were performed. The
patient recovered rapidly and the symptoms from the hypercortisolism were no more
present.
In this case, we discuss the multitude of problems, which may delay the diagnosis
and the pitfalls, that should be avoided in order to locate the tumour and to initiate
adequate therapy as early as possible. Furthermore, our case demonstrates the complexity
of diagnostic procedures, which demand most of the times a multidisciplinary approach.
In this setting, regular follow-ups in short time intervals and the use of novel imaging
techniques can finally cut the diagnostic “Gordian knot”.
Key words
glucocorticoids - pituitary adenoma - hyperandrogenemia
