SAT-248 Cushing’s Disease with Two ACTH-Producing Pituitary Tumors

Objective: The objective of this case report is to discuss a case of Cushing’s disease with two ACTH-producing pituitary tumors and emphasize consideration of repeat surgery as a treatment modality for unsuccessful initial surgery. Methods: We present a case of a patient with Cushing’s disease with two ACTH-producing pituitary tumors and a literature review. Results: A 36 year-old female found to have left supraclavicular fossa swelling was screened for Cushing’s syndrome. Midnight salivary cortisol levels elevated at 0.636 ug/dL and 0.316 ug/dL (<0.010–0.090 ug/dL). 24-hour urine cortisol 162 ug/24 hr (0–50 ug/24 hr). 1-mg dexamethasone suppression test 14.0 ug/dL. Serum morning cortisol 26.4 ug/dL with corresponding ACTH 66.7 pg/mL (7.2–63.3 pg/mL). MRI brain with and without contrast showed a 7-mm relatively hypoenhancing lesion of the anterior pituitary gland. 8-mg dexamethasone suppression test 2.7 ug/dL. She underwent transsphenoidal surgery (TSS) and pathology was consistent with a pituitary adenoma staining positive for ACTH. No residual tumor was seen. Postoperative morning serum cortisol 17.0 ug/dL and ACTH 79 pg/mL (9–46 pg/mL). She had repeat TSS and the area of resection was clean with no residual tumor but a second adenoma was found that was not visualized on MRI and was distinct from the initial lesion. Postoperative morning cortisol 0.7 ug/dL and ACTH <9 pg/mL (9–46 pg/mL). Pathology was consistent with pituitary adenoma staining positive for ACTH. She is now on steroids for central adrenal insufficiency. Discussion: First-line treatment for Cushing’s disease is surgical resection of the primary lesion (Nieman LK, Biller BMK, et al. Treatment of Cushing’s syndrome: an endocrine society clinical practice guideline. J Clin Endocrinol Metab. 2015; 100(8):2807–2831). Remission rates are 73–76% for selectively resected microadenomas but 43% for macroadenomas (Nieman et al. 2015). For patients who undergo a noncurative surgery, second-line therapies include repeat TSS, radiotherapy, medical therapy, and bilateral adrenalectomy. Repeat TSS is recommended particularly in patients who had evidence of incomplete resection or a pituitary lesion on imaging although this was not the case with our patient. Repeat TSS is cited to be successful in about 50–60% of cases (Patil CG, Veeravagu A, et al. Outcomes after repeat transsphenoidal surgery for recurrent Cushing’s disease. Neurosurgery. 2008;63(2):266–270) but carries an increased risk of hypopituitarism and lower likelihood of remission compared to initial surgery. Remission can be achieved more rapidly compared to other second-line treatments. Conclusion: In Cushing’s Disease with unsuccessful initial surgery, consideration for repeat TSS may be considered when there is access to an expert pituitary surgeon.