Takao Noshiro

Histological grading of adrenal and extra-adrenal pheochromocytomas and relationship to prognosis: A clinicopathological analysis of 116 adrenal pheochromocytomas and 30 extra-adrenal sympathetic paragangliomas including 38 malignant tumors

Pheochromocytomas and extra-adrenal sympathetic paragangliomas show varied histological patterns, and it is difficult to diagnose malignancy or predict the clinical course using current histological criteria. In the present study, we reviewed 146 sympathetic paragangliomas including 116 adrenal (102 unilateral, 14 bilateral) and 30 extra-adrenal tumors including 38 metastatic tumors. We developed a scoring scale according to the following six factors: histological pattern, cellularity, coagulation necrosis, vascular/capsular invasion, Ki-67 immunoreactivity, and types of catecholamine produced. The tumors were classified as well (WD), moderately (MD), and poorly differentiated (PD) types according to their scores. The frequency of these tumor types were 113 WD (77%), 27 MD (19%), and 6 PD (4%). Metastasis was observed in 15 of 113 WD (13%), 17 of 27 MD (63%), and all 6 PD (100%). Five-year survivals of patients with metastases were 92% with WD, 69% with MD, 0% with PD. Respective 10-yr survivals were 83%, 38%, and 0%. Differences between groups were statistically significant. The data show that using this grading scoring system for sympathetic paragangliomas correlates with both metastatic potential and patient survival.

Expression of urotensin II and its receptor in adrenal tumors and stimulation of proliferation of cultured tumor cells by urotensin II.

Urotensin II is a potent vasoactive peptide, which was originally isolated from fish urophysis. We studied expression of urotensin II and its receptor mRNAs in the tumor tissues of adrenocortical tumors, pheochromocytomas and neuroblastomas. Effects of exogenously added urotensin II on cell proliferation were studied in a human adrenocortical carcinoma cell line, SW-13 and a human renal cell carcinoma cell line, VMRC-RCW. The reverse transcriptase polymerase chain reaction (RT-PCR) showed expression of urotensin II and its receptor mRNAs in all the samples examined; seven pheochromocytomas, nine adrenocortical adenomas (four with primary aldosteronism, four with Cushing syndrome and one with non-functioning adenoma), four adrenocortical carcinomas, one ganglioneuroblastoma and five neuroblastomas, as well as four normal portions of adrenal glands (cortex and medulla). Urotensin II-like immunoreactivity was detected in one of eight adrenocortical adenomas, two of four adrenocortical carcinomas, one of six pheochromocytomas, and one of five neuroblastomas by radioimmunoassay, but not in normal portions of adrenal glands (detection limit; 0.2pmol/g wet weight). Treatment with urotensin II for 24h significantly increased number of SW-13 cells (at 10(-8) and 10(-7)mol/l) and VMRC-RCW cells (at 10(-8)mol/l). These findings raise the possibility that urotensin II may act as an autocrine/paracrine growth stimulating factor in adrenal tumors.

Changes in clinical features and long-term prognosis in patients with pheochromocytoma

To investigate changes in preoperative clinical features and the long-term outcome of tumor recurrence, mortality, and morbidity in patients with pheochromocytoma, we retrospectively examined changes in the clinical features by comparing 49 patients from 1957 to 1985 (group I) with 46 patients from 1986 to December 1995 (group II). In addition in these 95 patients (excluding 2 who had died before operation), we evaluated long-term postoperative outcome from the initial operation to August 1996 (909 patient-years). The mean age in group II was older than that of group I. The percentage of patients having proteinuria or hypertensive retinopathy in group II was less than that in group I. Of 20 patients with incidentally discovered pheochromocytoma, 7 (35%) were > or =60 years old, 7 asymptomatic, and 11 (55%) normotensive. Plasma and urinary catecholamines in these patients were significantly (P < .01) lower than in patients with pheochromocytoma having typical clinical features. Long-term cohort study showed 14 deaths. Relative survival rates were 91% at 5 years and 83% at 10 years and unchanged thereafter. The Kaplan-Meier estimate of pheochromocytoma-free survival was shorter in patients with a larger-than-median (60 g) tumor weight. Six patients had malignant recurrence 3 to 101 months (median, 45 months) after the initial operation. Of 65 patients confirmed alive at follow-up, 11 were hypertensive. In the Cox model, hypertension-free survival was not associated with age, a family history of hypertension, duration of hypertension, or creatinine clearance. Pheochromocytoma should be diagnosed from a wide spectrum of clinical features including those that are not generally suspected of resulting from excess catecholamines or hypertension, and after surgery, patients with this disease should be followed-up carefully for a long period (at least 10 years) because of the risk of tumor recurrence and the high prevalence of disease.

Neurofibromin and NF1 Gene Analysis in Composite Pheochromocytoma and Tumors Associated with von Recklinghausen’s Disease

Composite tumor of pheochromocytoma and neuroblastoma, or ganglioneuroma, or ganglioneuroblastoma (composite pheochromocytoma), also known as mixed neuroendocrine and neural tumor, are sometimes combined with neurofibromatosis type 1 (NF1). To better understand the relationship between NF1 and composite pheochromocytoma, an immunohistochemical study using anti-neuro-fibromin that is an NF1 gene product and DNA sequence of NF1 Exon 31 were carried out in five cases of composite pheochromocytoma and in various tumors from five patients with NF1. Neurofibromin was not expressed in Schwann cells and sustentacular cells of composite pheochromocytomas and was very weakly or negatively expressed in neurofibroma of NF1 patients. However, it was strongly expressed in ganglionic cells and pheochromocytoma cells of the composite pheochromocytomas and also in mucosal ganglioneuromas, a gangliocytic paraganglioma, and in pheochromocytomas from the patients with NF1. Although there was no mutation in NF1 Exon 31, it could not be ruled out that there were mutations in other sites of the NF1 gene. Neurofibromin insufficiency may induce abnormal proliferation of Schwann cells in composite pheochromocytomas as well as in neurofibromatosis.

Twenty-six-years' survival with multiple bone metastasis of malignant pheochromocytoma

Abstract The prognosis of metastatic pheochromocytoma is poor in general. There have been few instances of long-term survival reported. We report a case of a 44-year-old woman who has survived for 26 years after bone metastasis. She was diagnosed as having pheochromocytoma arising in the left adrenal medulla in 1974. Metastasis of pheochromocytoma in the first and third lumbar vertebrae and the right ilium was observed at the same time. The primary lesion was removed, and posterior lumbar spinal fusion was performed for immobilization. The metastatic lesion in the ilium was left untouched. After 26 years, she is well despite a recurrence of the tumors in the skull and a new metastasis in the left abdomen.

Expression of adrenomedullin mRNA in adrenocortical tumors and secretion of adrenomedullin by cultured adrenocortical carcinoma cells

Immunoreactive-adrenomedullin concentrations and the expression of adrenomedullin mRNA were studied in the tumor tissues of adrenocortical tumors. Northern blot analysis showed the expression of adrenomedullin mRNA in tumor tissues of adrenocortical tumors, including aldosterone-producing adenomas, cortisol-producing adenomas, a non-functioning adenoma and adrenocortical carcinomas, as well as normal parts of adrenal glands and pheochromocytomas. On the other hand, immunoreactive-adrenomedullin was not detected in about 90% cases of adrenocortical tumors (<0.12 pmol/g wet weight (ww)). Immunoreactive-adrenomedullin concentrations ranged from 0.44 to 198.2 pmol/g ww in tumor tissues of pheochromocytomas and were 9.2 +/- 1.2 pmol/g ww (mean +/- SD, n = 4) in normal parts of adrenal glands. Adrenomedullin mRNA was expressed in an adrenocortical adenocarcinoma cell line, SW-13 and immunoreactive-adrenomedullin was detected in the culture medium of SW-13 (48.9 +/- 1.8 fmol/10(5) cells/24h, mean +/- SEM, n = 4). On the other hand, immunoreactive-adrenomedullin was not detectable in the extract of SW-13 cells (<0.09 fmol/10(5) cells), suggesting that adrenomedullin was actively secreted from SW-13 cells without long-term storage. These findings indicate that adrenomedullin is produced and secreted, not only by pheochromocytomas, but also by adrenocortical tumors. Undetectable or low levels of immunoreactive-adrenomedullin in the tumor tissues of adrenocortical tumors may be due to very rapid secretion of this peptide soon after the translation from these tumors.

Altered sympathetic and vagal modulations of the cardiovascular system in patients with pheochromocytoma ☆: Their relations to orthostatic hypotension

To examine sympathetic and vagal cardiovascular regulatory mechanisms in the pathogenesis of orthostatic hypotension in pheochromocytoma, we continuously monitored blood pressure (Finapres) and RR interval (electrocardiogram) in supine and standing positions in 12 patients with pheochromocytoma, 43 patients with essential hypertension, and 30 normotensive subjects. Mayer wave power spectrum of systolic blood pressure variability (approximately 0.1 Hz) and respiratory power spectrum of the RR interval variability (approximately 0.25 Hz) were taken as measures of sympathetic vascular and cardiac vagal modulations, respectively. Systolic blood pressure decreased more upon standing in pheochromocytoma patients (-21 +/- 7 mm Hg) than in normotensive subjects (-5 +/- 2 mm Hg) or essential hypertensive patients (-3 +/- 2 mm Hg) (P < .005 for both), whereas heart rate tended to increase most in the pheochromocytoma group. Postural reduction in systolic blood pressure was highly correlated with postural increase in heart rate (reciprocal change in RR interval) in the pheochromocytoma group (r = 0.716, P < .01) suggesting that baroreflex is well functioning in those patients. The Mayer wave power spectrum in recumbency was extremely depressed in pheochromocytoma patients (1.1 +/- 0.2 mm Hg2) compared with normotensives (4.5 +/- 0.8 mm Hg2) or essential hypertensives (5.6 +/- 0.6 mm Hg2) (P < .001 for both). This parameter increased significantly with standing in all groups but remained lower in patients with pheochromocytoma (5.1 +/- 1.0 mm Hg2) than in normotensives (7.1 +/- 0.9 mm Hg2, P = NS), whereas essential hypertensive patients demonstrated far greater value (19.2 +/- 3.8, P < .01 for both). The respiratory power spectrum of the RR interval in recumbency of pheochromocytoma patients (189 +/- 54 msec2) was less than in normotensive subjects (714 +/- 100 msec2, P < .001) but did not differ from that in patients with essential hypertension (214 +/- 41 msec2). The respiratory power spectrum of the RR interval upon standing was markedly suppressed in pheochromocytoma patients (36.9 +/- 16.7 msec2) compared with normotensive subjects (129.5 +/- 23.6 msec2) or essential hypertensive patients (126.6 +/- 28.6 msec2) (P < .001 for both). Postural decrement in the respiratory power spectrum of the RR interval correlated positively with postural increase in heart rate (r = 0.577, P < .05) in patients with pheochromocytoma. After successful surgery (n = 9), the Mayer wave power spectrum of the systolic blood pressure and the blood pressure response to orthostasis were normalized. These data suggest that altered sympathetic vascular regulation is central to the pathogenesis of orthostatic hypotension in pheochromocytoma, whereas cardiac vagal regulation acts to compensate.

Ki-67 is an indicator of progression of neuroendocrine tumors

No current histological or cytological indices can distinguish reliably malignant from benign tumors in neuroendocrine tumors, including pheochromocytomas, pancreatic endocrine tumors, and carcinoid tumors. We investigated immunohistochemically the expression of Ki-67 in 52 neuroendocrine tumors, including 17 pheochromocytomas, 9 pancreatic endocrine tumors, 23 carcinoid tumors, 2 neuroendocrine carcinomas (NEC), and 1 neuroblastoma with liver metastasis. Of the 52 tumors, distant metastasis was observed in 4 pheochromocytomas, 2 pancreatic endocrine tumors, 4 carcinoids, 2 NEC, and 1 neuroblastoma. We classified these tumors into 3 groups; Groups A, B, and C, depending on the number of Ki-67-positive cells counted under a 200 x magnified field. Expression of Ki-67 was extremely high in group A (> 50 labeled nuclei/field), moderately high in group B (20–50 labeled nuclei), and very low in group C (< 10 labeled nuclei). There was a significant correlation between expression of Ki-67 and tumor progression. The tumors in group A progressed rapidly with the worst outcome; the tumors in group B progressed slowly but with a bad outcome; and the tumors in group C had no metastasis and a good prognosis. Ki-67 is an excellent indicator to assess progression of neuroendocrine tumors.

Expression of stanniocalcin in zona glomerulosa and medulla of normal human adrenal glands, and some adrenal tumors and cell lines

Stanniocalcin (STC) is a calcium (Ca)‐regulating hormone that was originally discovered in the fish Stannius body, which is a unique endocrine organ. Hypercalcemia increases STC secretion, which inhibits Ca uptake by the gills and normalizes serum Ca level. In this study we investigated the STC expression in human normal and abnormal adrenal cells. Immunohistochemistry using monoclonal antibody against STC revealed specific staining in zona glomerulosa and medulla of normal human adrenal glands. STC was also detected in human adrenal tumors, such as pheochromocytoma, differentiated neuroblastoma, and aldosterone‐producing adenoma, and cultured adrenal tumor cells (rat pheochromocytoma PC‐12 cells and human neuroblastoma NB‐1 cells). However, undifferentiated human adrenal neuroblastoma was negative for STC staining. Reverse transcription polymerase chain reaction demonstrated STC mRNA expression in cultured PC‐12 cells and NB‐1 cells. Following several studies indicating that zona glomerulosa cells of adrenal glands express neuroendocrine properties, STC expression in normal and abnormal adrenal cells provides additional evidence to support the neuroendocrine differentiation of these cells. In conclusion, STC may be useful as a new cell marker of adrenal glands under physiological and pathological conditions.

Expression of prolactin-releasing peptide and its receptor in the human adrenal glands and tumor tissues of adrenocortical tumors, pheochromocytomas and neuroblastomas

Adrenal tumors, such as pheochromocytomas, are known to express various peptides and their receptors. Prolactin-releasing peptide (PrRP) is a novel neuropeptide isolated from bovine hypothalamic tissues. In the present study, expression of PrRP receptor was studied in the human brain, pituitaries, adrenal glands and tumor tissues of adrenocortical tumors, pheochromocytomas, a ganglioneuroblastoma and neuroblastomas by reverse transcriptase polymerase chain reaction (RT-PCR) and Northern blot analysis. The presence of immunoreactive-PrRP in the adrenal glands and in these tumor tissues was studied by radioimmunoassay. Human brain tissues and pituitaries were obtained at autopsy. Normal portions of adrenal glands and tumor tissues were obtained at surgery. RT-PCR analysis showed expression of PrRP receptor in the human brain, pituitaries, normal portions of adrenal glands and various tumor tissues. Northern blot analysis showed high expression of PrRP receptor only in tumor tissues of pheochromocytomas, indicating that PrRP receptor expression is high in pheochromocytomas. Immunoreactive-PrRP was detected in normal portions of adrenal glands (0.162+/-0.024 pmol/g wet weight, n=4, mean+/-S.E.M.), four out of six cases of pheochromocytomas (0.050-7.9 pmol/g wet weight), one neuroblastoma and some adrenocortical tumors. The present study has shown that PrRP receptor mRNA was widely expressed in the brain tissues, pituitaries, adrenal glands and various tumors. The high expression of PrRP receptor in pheochromocytomas suggests potential pathophysiological roles of PrRP in these tumors.