An Unusual Case of Invasive, Plurihormonal Secretory Pituitary Macroadenoma Presenting as Cushing's Disease in a Patient with ESRD

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 163-194-Pituitary Disorders & Case Reports
Basic/Clinical
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-184
Thomas Creighton Mitchell*1, Fuad Shihab2, Dennis Shrieve2, William T Couldwell2 and Devaprabu Abraham3
1University of Utah, UT, 2University of Utah, 3University of Utah, Salt Lake City, UT
Background: We present a case of invasive secretory pituitary tumor in a patient with ESRD treated by peritoneal dialysis. Her renal replacement status presented unique challenges in the diagnosis of Cushing’s disease.   Pleurihormonal adenomas secreting hormones regulated by different transcription factors are exceedingly rare.   

Clinical Case: A 30-year-old woman with a history of hypertension and ESRD due to focal segmental glomerulosclerosis on peritoneal dialysis presented for evaluation of worsening diabetes, facial plethora and proximal muscle weakness.  A midnight salivary cortisol was elevated (1.03 µg/dL, n<0.112 µg/dL) and an overnight 1mg dexamethasone suppression test was abnormal (cortisol after 1mg of dexamethasone 27.6 µg/dL, n 0-5 µg/dL).  Consistent with Cushing’s disease, her ACTH was also elevated following 1mg dexamethasone (ACTH 38 pg/mL, n 6-58pg/mL).  Other abnormal labs include the following: elevated GH (73.7 ng/mL, n 0.01-8 ng/mL), Igf-1 (>1600 ng/mL, n 71-352 ng/mL), and prolactin (60.4 ng/mL, n 2.8-26 ng/mL).  An MRI of the pituitary showed a 31 x 26 mm sellar mass with invasion into the clivus, sphenoid sinus, and bilateral cavernous sinuses.  Despite detailed transphenoidal surgery, complete resection could not be accomplished due to the extensive invasion.  Immunohistochemistry of the resected adenoma showed strong staining for GH with scattered cells reactive for ACTH and prolactin.  AM cortisol decreased immediately following surgery (6.5 µg/dL, n 6-23 µg/dL).  She received adjuvant radiotherapy with 20Gy administered in a single fraction one month after surgery. 

Three months after radiation, she had a persistently abnormal overnight 1mg dexamethasone suppression test (serum free cortisol following 1mg dexamethasone 2.19 µg/dL, n 0.31-1.19 µg/dL; dexamethasone 849 ng/dL, n 140 - 295 ng/dL), elevated Igf-1 (>1600 ng/mL, n 71-352 ng/mL) and elevated GH (4.05 ng/mL, n 0.01-8 ng/mL).  An α-subunit was not elevated (1.1 ng/mL, n <= 1.2 ng/mL).  Follow-up MRI of the pituitary revealed significant resolution, however, residual tumor was evident in the right cavernous sinus.  Her clinical symptoms of hypercortisolemia and facial plethora resolved following surgery. P53 and MIB 1 index are pending.

Conclusion: This is the first description of a pituitary adenoma secreting ACTH, GH, and PRL presenting with Cushing’s disease in the setting of ESRD.

Nothing to Disclose: TCM, FS, DS, WTC, DA

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm