Endocrine Abstracts

Spontaneous remission of Cushing disease might be a phase of cyclic disease, but could also be explained by an ACTH-microadenoma infarction or hemorrhage. True remission must be differentiated from cyclic Cushing’s disease with prolonged follow up. 63-years-old female patient was referred to endocrinologist’s and presented with uncontrolled hypertension, type 2 diabetes, central obesity, hirsutism, swelling of the face and legs and a ’buffalo hump’. After additional investigation elevated ACTH (24.1pmol/l (n1.63-14.15)), basal cortisol (1187nmol/l (n147-726)) and high 24-hours urinary free cortisol 2236.4nmol/l (n138-524) were determined. Cortisol was not suppressed after low-dose dexamethasone suppression test. Pituitary MRI revealed 0.5x0.2x0.3cm hypointense zone in posterior pituitary. Petrosal sinus sampling was planned, but the patient was admitted to the emergency department with panniculitis in her limbs. After chest and abdominal CT scan 3.1x2.4cm tumor in left ventricle and 0.6cm hypointense tumor in the liver was detected. Patient case was discussed at multidisciplinary team and it was concluded that at that moment biopsy benefit would not outweigh the risks. Patient was treated with iv a/b. When inflammation markers decreased petrosal sinus sampling was performed. It confirmed pituitary source of ACTH production and right side lateralization which coincided with MRI data. During two months period from the first suspicion of pituitary microadenoma till the petrosal sinus sampling was performed, clinical symptoms of Cushing syndrome significantly decreased as well as hormone levels: basal cortisol level 1187->403.16nmol/l, ACTH 24.1->7.1pmol/l. Diabetes control significantly improved as well. The situation was interpreted as spontaneous remission and it was decided to continue active observation of the patient. However, 10 months later worsening of patient’s status was observed. Basal cortisol increased dramatically (1354nmol/l) as well as ACTH level (26.4pmol/l). Pituitary MRI was repeated: there was 0.5x0.2x0.6cm hypointense zone in posterior pituitary and transphenoidal pituitary adenoma surgery was performed. Histopathological analysis confirmed chromophobic pituitary adenoma. A few weeks after surgery increasing cortisol levels were observed, due to subtotal removal of pituitary adenoma (confirmed with MRI). For peristent hypercortisolism control, treatment with metyrapone was initiated. After 5 months of treatment metyrapone was halted due to development of adrenal insufficiency. The patient is normocortisolemic for 6 months already, despite of the remnants of pituitary adenoma on MRI and is only under the active follow up at the department. Spontaneous remission in Cushing’s disease is a very rare situation. There is still lack of data on pathophysiology, management and follow up strategies for this condition.