Brain Pathology Case of the Month - April 2012

Contributed by David M Atkinson, MD1, Ronald L Hamilton, MD2
Departments of 1Psychiatry and 2Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.


The patient was a 52 year old male with a history of Cushing's disease, initially diagnosed at the age of 18. At that time, his symptoms included increased weight, purple abdominal striae, diabetes mellitus, and polydipsia. He underwent a resection of a pituitary microadenoma at another hospital. However, due to persistently high cortisol levels following the surgery, he later underwent a bilateral adrenalectomy. Following the operation, he began hydrocortisone therapy, lost weight, and was able to maintain glucose control without diabetes medications. At the age of 32 his diabetes recurred, but he was able to maintain good glucose control up until age 51 at which time his HbA1C was greater than 7. He also had visual problems with significant reduction in right peripheral vision and moderate impairment in left. Testing revealed a greatly elevated serum ACTH at 5,082 pg/mL (normal is 9 - 46 pg/mL), but serum cortisol within normal limits 4 ug/dL. MRI scans found a large, contrast-enhancing mass in the pituitary fossa with extrasellar extension into the right cavernous sinus and displacement of the parasellar carotid posteriorly (Figs 1 and 2). The patient underwent endoscopic endonasal approach for debulking of the mass.


Sections showed a cellular tumor (Figs 3 and 4). Reticulin stains showed variation of reticulin within the tumor (Figs 5 and 6). Immunostaining for synaptophysin (Fig 7) ACTH (Fig 8) and cytokeratin (Cam 5.2, Figure 9) were positive in the tumor. Ki67 showed increased proliferation compared to most pituitary adenomas (Fig 10).


International Society of Neuropathology