20-year-old male presented with Cushing's syndrome. Diagnosed with an ACTH producing mixed metastatic medullary and follicular thyroid cancer [carcinoembryonic antigen (CEA) and Calcitonin 14mcg/L and 4,906pg/mL respectively]. On imaging metastatic to the right lateral and central lymph nodes.

Patient underwent total thyroidectomy, central neck with ipsilateral neck dissection. Prior to the surgery, he was admitted for etomidate infusion in ICU to lower his cortisol levels as well as started on Aldactone for management of his hypokalaemia and Valsartan for his hypertension. Total thyroidectomy and central neck dissection were performed removing clinically suspicious lymph nodes from level 6 and level 7.

Post operatively, calcitonin levels decreased immediately to 36.3 pg/mL from 4906pg/mL as well as the ACTH levels dropping to 0.3pmol/L from 46.4 pmol/L pre-operatively thus showing clinical response to the surgery. Patient was followed up 10 months post-surgery with persistently low calcitonin levels of 22.8 pg/mL, CEA 0.6 mcg/L, and ACTH of 1.1pmol/L. Repeat imaging 6 months did not show any local or distant recurrence.

As per the American thyroid association guidelines for the management of medullary thyroid carcinoma, the management plan was guided by radiological finding as well as calcitonin levels. ACTH and calcitonin levels were used as the prognosticating factors as well as a marker for relapse. Guidelines also recommend lymph node dissection of levels II to VI whereas for this patient, lymph nodes from level 7 were cleared from carotid to trachea. These lymph nodes aren't in the usual standard of dissection.