Endocrine Abstracts

Case report: A 65-year-old fisherman presented with altered mental status, agitation, generalised oedema, dyspnoea, liver impairment and severe persistent hypokalaemia (2.2 mmol/l). History: COPD, IPF (on steroids since May 2012), ex-smoker. Physical examination: deeply tanned, Cushingoid facies, severe proximal myopathy. Medications prior to admission: prednisolone 40 mg OD, furosemide 40 mg OD, inhalers, and lansoprazole. In a view of clinical and biochemical features of steroid access, the Endocrine referral was made.

Patient had the following abnormal endocrine tests: cortisol – 3118 nmol/l, ACTH – 632 ng/l, total chromogranin A – 480 μ/l, 5-HIAA – 551 μmol/24 h. CT thorax/abdomen showed multiple liver metastasis, pulmonary fibrosis, RUL nodule, enlarged paratracheal, subcarinal lymph nodes, bilateral adrenal hypertrophy.

CT haed/MRI of pituitary were normal. Liver biopsy confirmed the presence of poorly differentiated (very high Ki67 index – 90%) small cell neuroendocrine tumour which positively stained for TTF1, CK7, CD56, AE1/3, chromogranin, synaptophysin. Positive staining for TTF1 and CK7 are sought to be in favour of primary lung lesion.

The diagnosis of poorly differentiated metastatic small cell neuroendocrine tumour with ectopic ACTH secretion was made. Patient was started on metyrapone 1 g 4 hourly. Ketoconazole 200 mg OD was added later. His cortisol and LFT had initially improved and potassium normalised. Oncology team put him on 3-month course of carboplatin with etoposide. Further investigations suggested for carcinoid in a form of octreotide scan were not recommended by Oncology Department due to its relative insensitivity in the settings of poorly differentiated neuroendocrine tumour. Patient passed away just in 4 months since presentation despite intensive chemotherapy.

Conclusion: We reported this case because of the interesting clinical presentation of an ectopic ACTH secretion exacerbated by exogenous steroid intake. This case also shows the importance of good differential diagnosis of hypokalaemia. Treatment options were limited due to the aggressive nature of the tumour.