Type 1 neurofibromatosis and pheochromocytoma: Focus on hypertension

Clonidine suppression testing for pheochromocytoma in neurofibromatosis type 1

Compared with the general population, rates of pheochromocytoma are higher in neurofibromatosis type 1 (NF1) patients. However, pheochromocytoma testing is often plagued by false positive results. Here we present a patient with NF1, elevated urinary metanephrine levels, and an indeterminate adrenal nodule. Clonidine suppression testing aided diagnosis and led to definitive surgical treatment that confirmed a pheochromocytoma. Pheochromocytoma screening and clonidine suppression testing can both aid in the evaluation for catecholamine-secreting tumours.

Neurofibromatosis type 1 associated with pheochromocytoma and gastrointestinal stromal tumors: A case report and literature review

Neurofibromatosis type 1 (NF1) is a genetic disorder associated with neurofibromin 1 (NF1) gene mutation, which generates an increased risk of variety of tumor types. The current study reports a case involving NF1, pheochromocytoma (PHEO) and gastrointestinal stromal tumors (GIST). A 56-year-old man presented with abdominal pain and polypnea. Clinical investigation revealed multiple diffuse soft-tissue lesions throughout his body, and pigmented macules on the skin. Imaging analyses revealed thoracic scoliosis, multiple subcutaneous nodules in the abdomen and trunk, and a 7.0×7.7×8.9-cm oval-shaped, cystic mass in the left upper abdominal cavity. Immunohistochemical staining indicated that S-100 protein and synaptophysin were highly expressed in adrenal gland neoplasm, whilst CD117 and CD34 were highly expressed in small intestine tumors. The overall clinical and pathological finding suggested a diagnosis of NF1, giant PHEO and small intestinal stromal tumor. In addition, a literature review was conducted to identify the specific clinical features of patients with this condition. Only 11 similar cases have been reported worldwide. In the present study, paroxysmal hypertension occurred in the majority of patients, and GISTs tended to be located in the small intestine. In addition, the present study demonstrated that many of the patients had a poor prognosis. Therefore, the present study indicates that NF1-PHEO-GIST is a special type tumor with varied clinical symptoms, which may be associated with an increased risk for poor prognosis; however, more studies are required to confirm this.