Deoxyribonucleic acid flow cytometric study in pheochromocytomas and its correlation with clinical parameters

Pheochromocytomas: can malignant potential be predicted?

OBJECTIVES

The presence of metastatic lesions is the only acceptable fact to confirm malignant pheochromocytoma. Patients with malignant pheochromocytomas, however, have a very poor survival rate. The aim of our study was to postulate predictive values for malignant pheochromocytomas.

METHODS

We evaluated symptoms, diagnostic modalities, treatment, and long-term follow-up of 86 patients with 85 benign and 10 malignant pheochromocytomas. Parameters from the benign were compared with those of the malignant pheochromocytomas.

RESULTS

Preoperative 24-hour urinary dopamine was in the normal range for benign pheochromocytomas but increased in malignant pheochromocytomas (P<0.0001). Vanillylmandelic acid was elevated in both benign and malignant pheochromocytomas but higher in malignant than in benign tumors (P = 0.01). No differences could be shown in urinary epinephrine and norepinephrine samplings. Tumor location was divided into 77 adrenal (81%) and 18 extra-adrenal (19%) sites. Malignant pheochromocytomas were located more often at extra-adrenal sites (P = 0.03). There was no increased incidence of malignancy in patients with familial bilateral pheochromocytomas or multiple endocrine neoplasia. Tumors greater than 80 g in weight corresponded to malignancy (P<0.0001). Dopamine tumor concentration was higher in malignant than in benign pheochromocytomas (P = 0.01). Persistent arterial hypertension occurred in 9 (13%) of 72 benign and 6 (60%) of 10 malignant pheochromocytomas (P = 0.001). The 10-year survival rate was 94% for benign pheochromocytomas. All patients with malignant pheochromocytomas died within this period (P = 0.0001).

CONCLUSIONS

High preoperative 24-hour urinary dopamine levels, extra-adrenal tumor location, high tumor weight, elevated tumor dopamine concentration, and postoperative persistent arterial hypertension are all factors that increase the likelihood of malignant pheochromocytoma. Patients with these characteristics should have more frequent follow-up evaluations to identify malignancy at earlier states.

Composite Pheochromocytoma-Ganglioneuroma of the Adrenal Gland: An Uncommon Entity with Distinctive Clinicopathologic Features

Background: Adrenal composite pheochromocytoma-ganglioneuroma is uncommon. The aim of this study is to investigate the characteristics of patients with this tumor. Methods: Histologic features of 46 pheochromocytomas diagnosed over a 28-year period (1971-1998) were reviewed. The clinical records, pathologic features, and ploidy patterns of patients with composite pheochromocytoma-ganglioneuroma were studied. Cases reported in the literature were also reviewed and compared with typical pheochromocytomas. Results: Four patients (two men; two women) with composite pheochromocytoma-ganglioneuromas were found. The tumors comprised 8.7% of pheochromocytomas. The two male patients with composite tumors were younger than the two female patients (age = 32, 52 vs 73, 75, respectively). The radiologic, gross, and microscopic appearances of the tumors were heterogeneous. One patient had malignant tumor with distant metastases. Flow cytometric analysis showed that the pheochromocytoma component was aneuploid and the ganglioneuroma portion was diploid. A review of the literature showed 31 adrenal composite pheochromocytoma-ganglioneuromas. Composite tumors were seen in older patients and were bigger than typical pheochromocytomas. Conclusion: Composite pheochromocytoma-ganglioneuromas had distinctive clinicopathologic features. Life-long clinical and biochemical follow-up of these patients is essential in view of the non-diploid DNA pattern.