Adrenal pheochromocytomas are rare catecholamine-secreting tumors that originate from chromaffin cells in the adrenal medulla, and giant pheochromocytomas with cystic changes are particularly rare. We report a case of a 46-year-old man who presented with episodic hypertension and headache. Radiographic studies showed an 18-cm cystic mass in the left upper quadrant of the abdomen; further workups, which included light microscopy, immunohistochemical, and electron microscopic analysis, revealed a pheochromocytoma of the left adrenal gland. Cytogenetic analysis and genetic mutation analyses for von-Hippel-Lindau (VHL), rearranged during transfection (RET), and succinate dehydrogenase complex subunit B (SDHB) genes were also performed but failed to reveal any abnormalities within the tumor cells.

Candidate gene mutation analysis in bilateral adrenal pheochromocytoma and sympathetic paraganglioma.Endocr Relat Cancer. 2007 Jun;14(2):453-62.

Pheochromocytomas (PCCs) are rare tumors that arise from chromaffin tissue in the adrenal medulla, but can also occur in the abdomen outside the adrenals and are then called sympathetic paragangliomas (sPGLs). According to the literature, between 15 and 25% of apparently sporadic adrenal PCC and sPGL are caused by germline mutations in RET, von Hippel-Lindau disease (VHL), succinate dehydrogenase subunit B (SDHB), or subunit D SDHD. However, few studies have addressed the mutationfrequency of these candidate genes in selected subgroups of PCC andsPGL, such as bilateral adrenal PCC or extra-adrenal sPGL, and none have looked at somatic mutations by analyzing tumor tissue. Therefore, we have investigated the occurrence of germline and somatic mutations in RET, VHL, SDHB, and SDHD in comparatively large series of bilateral adrenal PCC (n = 33 patients) and sPGL (n = 26 patients), with the aim of determining the mutation frequency of each of these genes and to establish a genetic testing algorithm. Twenty-one RET, two VHL germline, and one SDHD mutations were found in the patients with bilateral adrenal PCC. In sPGL, one novel SDHB germline and one novel SDHB somatic mutation were observed. In addition, two SDHD germline mutations were found. We conclude that germline RET mutations are predominantly found in bilateral PCC, and that somatic and germline SDHB and SDHD mutations usually occur in sPGL, which has practical consequences for genetic testing algorithms. We suggest that sequential mutation analysis should be directed first at RET, followed by VHL and SDHD for patients with bilateral adrenal PCC at diagnosis, and at SDHB and SDHD for patients with sPGL.