Phaeochromocytoma

Oncocytic Pheochromocytoma with Cytokeratin Reactivity

A large hemorrhagic pheochromocytoma (275 g) is described in a 38-year-old obese woman who had no history of sustained or sporadic hypertension. The tumor was unusual histologically because of the striking presence of oncocytic cells. Immunohistochemical studies revealed the positivity for neuron-specific enolase, synaptophysin, and cytokeratin CAM 5.2. Electron microscopy demonstrated neurosecretory dense core granules characteristic of a pheochromocytoma. Oncocytic pheochromocytoma was briefly documented in previous case reports but has not been well recognized. The expression of cytokeratin by pheochromocytoma is also very rare and has been described in a single study in the literature. This case had both unusual clinical and pathologic manifestations and is the first report of a pheochromocytoma with coexistence of oncocytic changes and cytokeratin immunoreactivity.

Pheochromocytoma in children: 15 cases

Pheochromocytoma is an uncommon tumor in childhood; nevertheless, 20% of all pheochromocytomas are found in the pediatric population. Fifteen children have been treated in our institution from 1962 to 1990. One percent of patients referred over the same period for investigation of high blood pressure were found to have a pheochromocytoma. The majority of patients have hypertension. It varies in intensity and is paroxysmal in about half the patients. Many pediatric cases of unilateral, bilateral, extra-adrenal, familial, and recurrent pheochromocytomas have been reported. We reviewed our 28 years experience with this tumor and concentrated on the diagnosis, the preoperative and operative management, and the occurrence of the multiple endocrine neoplasia syndromes.

Naloxone provokes catecholamine release in phaeochromocytomas and paragangliomas

The effects of low- (2 mg) and high-dose (10 mg) intravenous naloxone administration on circulating plasma catecholamines in four patients with proven and two patients with suspected phaeochromocytomas have been evaluated. In three out of four patients with confirmed phaeochromocytomas or paragangliomas, 10 mg naloxone resulted in a marked rise (290-575%) in circulating noradrenaline; despite combined alpha and beta-adrenoceptor blockade, in two out of four cases systolic and diastolic pressures rose whilst pulse rate fell. No response was seen to 2 mg naloxone in any patient. No humoral or pressor response was obtained in the fourth patient, who may have been secreting maximal levels of plasma noradrenaline at the time of study. In the two patients with suspected phaeochromocytoma, there was no response to naloxone: further investigations failed to reveal a source of abnormal catecholamine secretion in these patients. It is concluded that naloxone represents a new pharmacological agent which can provoke catecholamine release in patients with phaeochromocytomas; in such patients, endogenous opioids may regulate catecholamine release either from the tumour itself or from the enhanced peripheral catecholamine stores.

Malignant pheochromocytoma with ACTH production

An autopsy case of a 54-year-old woman with malignant pheochromocytoma and ectopic ACTH production was reported. Noradrenaline was increased in 24 hour urine and in the blood sample from the left adrenal vein. Hormone assay studies of the tumor tissue and plasma revealed abnormally high levels of ACTH. Formaldehyde fume induced fluorescence method demonstrated biogenic amine in the tumor cytoplasm. Electron microscopic examinations also disclosed numerous neurosecretory granules in the tumor cytoplasm. These findings confirmed that this pleomorphic carcinoma of the left adrenal gland was one of the APUDoma originating from the adrenal medulla, so-called pheochromocytoma.

Clinico-pathological and ultrastructural characteristics of pheochromocytoma. An analysis of 55 cases

58 tumors of pheochromocytoma from 55 cases were studied clinico-pathologically and electron-microscopically. In this series, males were predominant and the number of left adrenal pheochromocytomas was 1.6 times that of right ones. Extraadrenal pheochromocytomas amounted to 41.4%. All 5 malignant pheochromocytomas in this series arose from extraadrenal paraganglia. Two types of secretory granules corresponding to the epinephrine and norepinephrine granules in the normal adrenal medulla were discerned in all 13 tumors examined under electron microscope. The contents of different types of granules were compared with urinary catecholamine excretion, and no apparent correlation was disclosed. Large amount of "E" granules in tumor cells of some cases might be associated with very low level of urinary epinephrine, while in the other cases, the reverse was true. The amount of catecholamine excreted in urine also bore no relation to the size of the tumor.

Diabetes and arterial hypertension

The epidemiology, pathogenesis, significance and management of hypertension in diabetic subjects are discussed. In Type 1 diabetes the presence of diastolic hypertension is closely related to the presence of diabetic nephropathy, from the stage of persistent proteinuria onwards. There may also be some elevation of systolic pressure. The apparent increased prevalence of hypertension in Type 2 diabetes is largely explicable, directly or indirectly, by obesity but there may be an excess of systolic hypertension among elderly patients. Hypertension in the diabetic population is associated with an increased incidence of both microvascular and macrovascular complications, but whether the high blood pressure is causal is not clear. The possible roles of sodium and insulin, the renin-angiotensin system, catecholamines and physical factors are explored. All current antihypertensive agents have additional limitations and disadvantages when used in diabetic patients: diuretics and beta-blockers are probably the initial drugs of choice. Only in the case of diabetic nephropathy is there yet reasonable evidence of antihypertensive treatment reducing the rate of progression of the disease.