Pituitary abscess is an unusual cause of sella turcica enlargement. Because its presentation closely mimics that of a pituitary tumor, the condition is seldom recognized preoperatively. Most cases have been of bacterial etiology; however, a single patient with a primary mycotic pituitary abscess secondary to Aspergillus species has been reported. That patient died of diffuse Aspergillus meningoencephalitis following a transfrontal craniotomy. In the present case, a woman with primary pituitary aspergillosis survived her infection with virtually intact pituitary function following a transsphenoidal approach which avoided contamination of cerebrospinal fluid. Postoperative amphotericin-B and 5-fluorocytosine therapy probably contributed greatly to her survival. Factors that should alert the clinician to the presence of a pituitary abscess in a patient with sella turcica enlargement are prior episodes of meningitis, sinusitis, or cerebrospinal fluid abnormalities, including pleocytosis, depressed glucose, and elevated protein.

We have studied a 57-yr-old woman with cyclic Cushing's syndrome of apparent pituitary origin who had a predominant cycle of 2-6 days. The patient also demonstrated an abnormal circadian rhythm, with afternoon peaks of plasma ACTH and plasma cortisol. In addition to these abnormal biorhythms, Fourier analysis showed what appeared to be a separate 35-day cycle. After 35 days of consecutive urinary free cortisol measurement, the patient was given cyproheptadine. During therapy with this agent, the urinary free cortisol levels fell dramatically, but cyclic secretion continued, albeit with a diminished amplitude. During general anesthesia for a bilateral adrenalectomy, there was a striking increase in the plasma ACTH level, and the ACTH concentration remained high in both the immediate and late postoperative periods. These observations indicated that stress could overcome cyclic ACTH secretion and that cortisol exerted feedback suppression on ACTH secretion. Although this is the predictable response for classic pituitary-dependent Cushing's syndrome, it is of interest in cyclic Cushing's syndrome, since previous studies of this entity have implied that cortisol secretion is independent of stimulation or feedback.

No abstract

No abstract