Abstract
A 79-year-old woman, seen at our hospital for investigation of anemia and fecal occult blood, was diagnosed as having cecal cancer and underwent FDG-PET to scrutinize metastasis. PET revealed high FDG accumulation in the bilateral adrenal glands, and CT scan disclosed swelling of the left adrenal gland. The total urophanic metanephrine level was high and 131I-meta-iodobensylguanidine scintigraphy showed an accumulation in the left adrenal gland. From these findings, pheochromocytoma of the left adrenal gland was diagnosed, and laparoscopic left adrenalectomy was performed with right colectomy. The pathologic diagnosis was adrenal medullary hyperplasia showing extension of the medullary layer due to diffuse enlargement and proliferation of adrenal medural cells, and a high ratio of the medulla to the cortex (2 : 1).
Twenty cases of adrenal medullary hyperplasia, including our case, have been reported in Japan. This disease is more common among men and in the left side, and can be accompanied with ipsilateral adrenal cortex adenoma, contralateral pheochromocytoma or multiple endocrine neoplasia type 2. Because this disease clinically mimics pheochromocytoma, it is preoperatively diagnosed as pheochromocytoma in most cases. Precise clinical diagnosis remains to be determined as more data are obtained.
