CASE 9088 Published on 04.02.2011

Ectopic ACTH secretion from poorly differentiated carcinoma of the liver

Section

Abdominal imaging

Case Type

Clinical Cases

Authors

Babu A, Ali Tarig

Patient

69 years, female

Categories
Area of Interest Liver, Abdomen ; Imaging Technique Ultrasound, CT
Clinical History
A 64-year-old lady was admitted with hallucinations, pressured speech, emotional fluidity, distraction, transient memory impairment and mutism. She complained of feeling of swollen legs and face and also complained of increased thirst. On examination she had hyper-pigmentation of face and trunk.
Medical history: Hypothyroidism. Ductal carcinoma in situ of breast (operated).
Imaging Findings
Investigations showed hypokalaemia (3.3mmol/L), high normal sodium (145mmol/L). Urinalysis revealed very high 24 hour urinary free cortisol (>1400micrograms/24hr). Plasma ACTH levels were >20pmol/L. Further investigations with ultrasound showed hepatomegaly with mass lesion in the right lobe of the liver (Fig 1). Unenhanced and contrast-enhanced computed tomography of the abdomen showed mass lesion within the liver, with no other organomegaly or lymphadenopathy (Fig 2,3,4,5).Histological diagnosis of the mass lesion revealed poorly differentiated carcinoma. The cell surface receptors were positive for cytokeratin and for neuroendocrine markers suggesting source for ectopic ACTH.
Discussion
Ectopic ACTH production is rare. On review of literature, ectopic ACTH-secreting tumours include carcinomas of the lung (small cell carcinoma and bronchial carcinoids), thymus, and pancreas [2,6]. There are very few reports of similar cases and carcinomas have been found in the lung, nasopharynx and metastatic deposit in the liver from anorectal carcinoma [1,2,3,4]. Secretion of ACTH results in bilateral adrenocortical hyperplasia, adrenal hyperfunction, and resultant Cushing’s syndrome [9].
Cushing’s syndrome often presents a diagnostic challenge, particularly in the early stages when the signs and symptoms are nonspecific.
The classic description of proximal muscle weakness, wide purple abdominal striae, and increased supraclavicular fat occurs in only a minority of patients [5].
A 24-hour urine-free cortisol level that is more than 4 times the upper limit of normal is diagnostic for Cushing’s syndrome. Four methods are accepted for the diagnosis of Cushing syndrome: urinary free cortisol level, low-dose dexamethasone suppression test, evening serum and salivary cortisol level, and dexamethasone–corticotropin-releasing hormone test.
Plasma ACTH levels distinguish ACTH-dependent from ACTH-independent causes of Cushing’s syndrome. ACTH-dependent sources include pituitary hypersecretion of ACTH (Cushing’s disease), ectopic ACTH-secreting tumours, and ectopic CRH-secreting tumours [5].
Definitive treatment involves surgical resection of the primary lesion, but in our case it was risky to operate on the lesion in the liver and as pitutory lesion was not identified, medical treatment was considered appropriate. In case of ACTH-producing tumours resection of the primary lesion will induce remission of symptoms, and as shown in carcinoids producing ACTH, the return of normal adrenal function [5]. Our patient received metyrapone with good control of symptoms. The patient also received radiotherapy to the lesion in the liver with a view to control high cortisol and had partial success. Bilateral adrenalectomy is performed in such cases to control the effects and complications of high cortisol. Best management depends on the individual case basis depending on the cause of Cushing’s syndrome.
The take home message is to exclude medical cause for all psychiatric presentations. We need to always look for the source of Cushing’s syndrome and radiological investigations are invaluable in looking for a source. Main goal of treatment is to control high cortisol levels in order to prevent its undesired effects.
Differential Diagnosis List
Cushing's syndrome secondary to poorly differentiated carcinoma of the liver
Cushing's syndrome
Psychoses
Final Diagnosis
Cushing's syndrome secondary to poorly differentiated carcinoma of the liver
Case information
URL: https://www.eurorad.org/case/9088
DOI: 10.1594/EURORAD/CASE.9088
ISSN: 1563-4086