Endocrine Abstracts

Introduction

Ectopic Cushing’s syndrome(ECS) is responsible for 15–20% of all cases of ACTH dependent Cushing’s syndrome. We present here a very rare case of ECS due to an acinic parotid carcinoma (ACC).

Presentation

A 44 year old woman with a medical history of metastatic ACC parotid carcinoma and type 1 diabetes mellitus (T1DM), referred to our department, due to cushingoid features, progressive fatigue, inability to walk and severe hypokalcemia (serum potassium (P) 2.4 mEq /l) refractory to replacement. The last four months she gained weight, had difficulties to control her diabetes, inability to climb stairs and became hypertensive. Physical examination revealed a cushingoid appearance, with centripetal obesity, moon face, enlarged supraclavular fat pads, proximal muscle weakness, mild pigmentention and thinning of the skin and pheripheral oedema. Her blood tests revealed hypercortisolemia with loss of diurnal rhythm [cortisol 8pm 64 µg/dl, ( < 18 µg/dl), salivary cortisol 8pm 23.2 µg/dl ( < 0.783, µg/dl), 24 h UFC 3468 µg ( < 120 µg/dl)], high ACTH levels [ACTH 439 pg/ml, ( < 60 pg/ml)] and hypokaliemic metabolic alcalosis.(P 2.4 mEq/l, ABG’s: ph = 7.47, PCO₂ = 31 mm/Hg, PO₂ = 105 mm/Hg, HCO_3– = 22.6 mmol/l). Recent imaging revealed extended metastatic disease, with no pathology of pituitary or adrenal glands. The diagnosis of ECS was made and due to the severity of her clinical picture and her rapid deterioration, no further confirmatory test were done and the patient started on fluconazole 400 mg iv/d, metyrapone 3 gr/d, spironolactone 100 mg/d and potassium replacement. Due to the extensive metastatic disease, resection of the tumor was not possible. Eight days later the patient had a remarkable clinical improvement and laboratory findings showed serum and salivary cortisol within the normal range. Five months after the diagnosis of ECS, her hypercortisolemia remained controlled but the patient had bone marrow infiltration and passed away.

Conclusions

Acinic cell parotid carcinoma, an aggressive tumor, is a very rare cause of ECS, with only six more cases to be reported so far. All patients presented with severe weakness and hypokaliemia. Due to the scarcity and the aggressiveness of these tumors, earlier diagnosis and treatment can be still a changeling issue but may affect the outcome.