This may be related to the lack of endocrine secretory granules in the GCC cells and evident by only scattered or absent tumor staining for chromogranin A. In a small study, plasma chromogranin A and urinary 5-HIAA were assessed at the time of referral and during the follow-up period and CgA was elevated in only two of four patients with disseminated disease [24]. Here, CGA is linked to neoplasm.