Endocrine Abstracts

A 16 year old previously healthy boy from Manipur, India was admitted with rapid onset quadraparesis, vomiting and diarrhoea, on a background 3 month history of increasing facial puffiness and progressive widespread rash. Investigations revealed hyperglycaemia, hypokalaemia and a raised ESR. The basal serum cortisol was 103 μg/dl (n=7–22 μg/dl) at 0800 h. 24-h urinary free cortisol failed to suppress with 8 mg of dexamethasone. Plasma ACTH and serum aldosterone were both markedly elevated at 263 pg/ml (n=0–40 pg/ml) and 528 pg/ml (n=25–31 pg/ml) respectively.

Imaging revealed mediastinal widening on chest radiography. A large thymic mass with focal liver lesions and vertebral sclerotic lesions was detected on CT. No abnormalities were detected upon MRI of the brain. Fine needle aspiration of the mediastinal mass revealed round cell lesions that morphologically resembled a neuroendocrine tumour.

The patient was diagnosed with an ACTH-secreting non pituitary tumour of the thymus, with infiltration of the liver and bone. Due to advanced disease progression he was not suitable for surgical resection. He was symptomatically managed with long acting Octeotride and followed up in clinic.

Neuroendocrine tumours (carcinoid and neuroendocrine carcinoma) of the thymus are extremely rare, and may present with Cushing’s syndrome from ectopic ACTH excretion. It carries a worse prognosis compared to thymomas, requiring aggressive therapy, hence accurate early diagnosis is essential. Resection is the therapeutic modality of choice for thymic carcinoids that have not metastasised. Extrathoracic metastasis has been reported in only 20–30% of cases and are associated with poor prognosis. We present a rare case of ACTH secreting tumour from the thymus with extra-thoracic metastasis to the liver and bones. Subsequently, we review and discuss recent literature on the use of the somatostatin analogue Octreotide in symptomatic management of advanced carcinoid tumours.