Endocrine Abstracts

Introduction: Cushing’s disease (CD) accounts for approximately 80% of cases of Cushing’s syndrome. Almost all patients with CD have a pituitary adenoma. The tumors are usually microadenomas, only approximately 5 to 10 percent are macroadenomas. Pituitary adenomas arise from epithelial pituitary cells and account for 10–15% of all intracranial tumors. Pituitary imaging is important in confirming the diagnosis of pituitary macroadenoma and also for determining the differential diagnoses of other sellar lesions. Case report: A 27-year-old woman was referred with a 2-week history of headache, blurred vision, edema, amenorrhoea, acne and 14 kg weight gain. Three months previously, her gynecologist had diagnosed hyperprolactinemia (PRL-1053 U/ml) and had started treatment with Cabergoline ¼ tab. 2 times per week. She stopped the treatment without doctor’s permission. On examination, there was no galactorrhoea and no purple stretch marks, BMI-19 kg/m², BP-110/70 mmHg, P-76’, regular. Investigations: MR scan of brain – chiasm-compressing adenoma with suprasellar extension 1.2x2.0x1.5 cm, CT scan – without adrenal hyperplasia, PRL-1053 U/ml (102-496), TSH-0.696 mIU/ml (0.27-4.2), FT4-10.76 pmol/l (12-22), FT3-3.09 pmol/l (3.1-6.8), LH<0.100 mIU/ml (2.4-12.6), FSH-0.954 mIU/ml (3.5-12.5). Serum ACTH and Cortisol were not performed properly, the patient couldn’t menaged collecting 24 h urine as well. All other investigations were in normal range. She was diagnosed with macroadenoma pituitary, hyperprolactinemia, central hypothyroidism, secondary hypogonadism. We prescribed Dopamine agonist and Levothyroxine. 2 weeks later she presented new Lab results: 08:00 ACTH-25.03 pg/ml (7.2-63.3), Cortisol-1271 nmol/l (172-497). The high-dose dexamethasone test was performed; proper fall of cortisol was not achieved. CD was diagnosed and she was referred for adenomectomy to neurosurgeon. Buffalo Hump and purple stretch marks first appeared some days before surgery. Transsphenoidal adenomectomy was performed. After surgery replacement therapy has begun.

Conclusion: Patients with macroadenomas are more likely to have supranormal plasma ACTH concentrations than are those with microadenomas (83 versus 45 percent), and the concentrations are less likely to fall with high doses of dexamethasone, as it was described in our case. The treatment of choice for patients with CD is transsphenoidal surgery and resection of the pituitary tumor.

Reference: 1. Katznelson L, Bogan JS, Trob JR, et al. Biochemical assessment of Cushing’s disease in patients with corticotroph macroadenomas. J Clin Endocrinol Metab 1998; 83:1619. 2. Woo YS, Isidori AM, Wat WZ, et al. Clinical and biochemical characteristics of adrenocorticotropin-secreting macroadenomas. J Clin Endocrinol Metab 2005; 90:4963.