Endocrine Abstracts

Diabetes in paraneoplastic Cushing is often severe with a risk of acute metabolic complications.

Observation n° 1: A 36-year-old patient, with no medical history, was hospitalized for inaugural diabetic ketoacidosis with no intercurrent infection. The physical examination found facio-truncal obesity, amyotrophy of extremities, melanoderma, arterial hypertension and severe psychiatric disorders. The blood tests showed an hypokalemia at 1.9 mmol/l. High doses of insulin were required to control the diabetes. The diagnosis of an ACTH-dependent Cushing Syndrome was retained in the presence of high cortisol levels (2000 nmol/l), non-suppressed after dexamethasone suppression test (DST), and high ACTH levels at 466 pg/l. Conventional localization techniques (Hypothalamic-pituitary MRI, cervico-thoraco-abdominopelvic CT, bronchial fibroscopy, octreoscan scintigraphy) failed to show any tumor. Bilateral adrenalectomy (in two phases) was performed because of the severity of the patient’s condition with no obvious etiology. The clinical course was marked by an improvement of the clinical signs and even a diabetes remission (we stopped all antidiabetic drugs). Two years later, Cushing syndrome recurred with the reappearance of diabetes requiring an insulin therapy. Cervicothoracic CT showed a right anterior mediastinal nodule and it was octreoscan-positive. The patient had a total thymectomy. Histology confirmed an atypical carcinoid stage III thymos tumor. The patient underwent radiotheray. The Cushing syndrome disappeared and the diabetes was well balanced under low metformin dose.

Observation n°2: A 35-year-old patient with no medical history, smoking 35 pack-year, was hospitalized for inaugural diabetic ketoacidosis requiring intensive insulin therapy. The physical examination found a patient with debilitating medical conditions, facio-truncal obesity and melanoderma. The blood tests showed an hypokalemia. The diagnosis of ACTH-dependent Cushing was retained in the presence of hypercorticism (cortisol=2900 nmol/l), non-suppressed after DST, and high ACTH levels (980 μg/l). This was a paraneoplastic cushing due to pulmonary neoplasia identified on chest X-ray and thoracic CT. The diabetes remained very unbalanced (Glycemia at 30 mmol/l) despite high doses of insulin (>0.5 IU/kg per day). The evolution was quickly fatal. The patient died of acute respiratory failure during bronchial fibroscopy.

Conclusion: These two cases clearly show that secondary diabetes can be very severe and difficult to balance based on the severity of the underlying endocrinopathy.