Selective venous sampling directly from cavernous sinus in Cushing's syndrome.

Using superselective catheterization technique, venous sampling directly from the cavernous sinus was performed in seven patients with Cushing's disease and one patient with ectopic ACTH secreting tumor. In Cushing's disease the central/peripheral (c/p) gradients of ACTH in the cavernous sinus (11.9-111.1; mean, 49.6) were much greater than those in the inferior petrosal sinus (1.0-52.0; mean, 14.0). The intercavernous gradients of ACTH provided correct lateralization in all patients but one who had a midline tumor. A patient with ectopic ACTH secreting tumor showed no gradients of ACTH both in the cavernous sinus and in the inferior petrosal sinus. The c/p gradients of PRL were smaller than those of ACTH in the cavernous sinus, inferior petrosal sinus, and jugular vein. The gradients of ACTH and PRL essentially indicated the same laterality in Cushing's disease, whereas the intersinus gradient of PRL provided a false laterality in two patients with a midline tumor. No complications have been observed during and after the sampling procedure. Thus, we conclude that 1) the selective sampling directly from the cavernous sinus offers sufficient c/p gradients (more than 10) for the reliable diagnosis of Cushing's disease, 2) CRH stimulation during the sampling and the simultaneous measurement of PRL are not necessary in this method, 3) the high concentration of pituitary hormones obtained by this sampling may be useful for other clinical investigations.