Spectrum of pheochromocytoma in the 131I-MIBG era

Flow cytometric DNA analysis for determination of malignant potential in adrenal pheochromocytoma or paraganglioma: an Indian experience

BACKGROUND

We analyzed the histological features and DNA flow cytometric results in 34 patients with pheochromocytoma and paragangliomas and attempted correlation with the biological behavior for determination of the malignant potential of these tumors.

METHODS

DNA analysis was done on a FACSort flow cytometer using paraffin-embedded tissues. Histopathological analysis was performed using parameters, i.e., cell size (large, medium, and small), cell size variation, mitotic rate, nuclear pleomorphism, golden yellow to brown pigment in the tumor, necrosis, and venous invasion.

RESULTS

Six tumors had high (>5/10HPF) mitotic rate while venous invasion was seen in three tumors. Fifty percent (18/34) of patients had aneuploid tumors, and 68% (23/34) of patients had high (>10%) S-phase fraction tumors. Aneuploidy correlated with >5/10HPF mitotic rate (P <.05) and diploidy with golden yellow to brown pigment (P <.01). The patients with aneuploid tumor had a worse prognosis than patients with diploid tumors (P =.004). No such difference was observed with low and high S-phase fractions (P =.748), presence and absence of venous invasion (P =.927), and mitotic rate (P =.159). Nuclear pleomorphism and necrosis were not significant factors in prognosis.

CONCLUSIONS

Flow cytometric DNA analysis of paragangliomas and pheochromocytomas correlated with biological behavior in the patients with regard to metastasis and overall survival in the patients.

Tumour size: the only predictive factor for 131I MIBG uptake in phaeochromocytoma and paraganglioma

BACKGROUND

131I Meta-iodobenzylguanidine (131I MIBG) scintigraphy can detect chromaffin tumours with a high specificity but its sensitivity remains limited. In this study, the influence of clinical features and tumour pathology on the results of 131I MIBG of patients with phaeochromocytomas and paragangliomas was examined.

METHODS

The records of 104 patients operated on for chromaffin tumours who had pre-operative 131I MIBG were reviewed. Demographic data, clinical features, biochemical results and pathology of tumours were analysed. The size of the tumour was assessed by the three measured diameters of the specimen and its calculated volume. Univariate relationship between tumours' characteristics and the results of 131I MIBG were examined.

RESULTS

Out of 119 tumours, 104 (87%) were detected by 131I MIBG. Mean +/- SD largest diameter and volume of the tumours were 6.0 +/- 2.4 cm (range 0.8-11.5 cm) and 68 +/- 74 cm3 (range 0.2-421 cm3). Results of 131I MIBG were significantly correlated with both the largest diameter of the tumour (P < 0.01) and by its volume (P < 0.001). 131I MIBG was negative in 35.5% of tumours < 20 cm3 and in 2.6% of those < 20 cm3. No other criteria were correlated with positive 131I MIBG, including aetiology, pathology or catecholamine secretion pattern.

CONCLUSIONS

The result of 131I MIBG scanning in patients with chromaffin tumours is significantly correlated with the size of the tumour.

"The" pheochromocytoma: a benign, intra-adrenal, hypertensive, sporadic unilateral tumor. Does it exist?

This study aims to examine the frequency of the pheochromocytoma (pheo), defined as a "benign, intra-adrenal, hypertensive, sporadic, unilateral tumor." Three large series amounting to 310 subphrenic chromaffin tumors operated over periods of 17, 23, and 41 years, respectively, have been reviewed. Among those combined 310 pheos, 48 (15.5%) were malignant (i.e., metastatic) and 262 (84.5%) were benign; 42 (13.5%) were ectopic (35% of malignant tumors versus 9.5% of benign tumors); 230 (74.2%) were hypertensive (74% of benign tumors versus 73% of malignant tumors); 29 (9.4%) were bilateral, including 23 patients with a family history; 41 (13.2%) of patients had MEN II type A or B syndrome; and 20 (6.5%) occurred in a phacomatosis setting. Some of the patients had a non-MEN family history of pheo (n = 5), seemingly sporadic hyperparathyroidism (n = 4), or other associated neuroendocrine tumor (n = 9). Sometimes several of these features were combined. Finally 125 (40.3%) cases fitted the classic description of the tumor, 47.0% at the time of initial presentation and 40.3% at the end of follow-up. Late occurrence of metastases or metachronous diagnosis of familial disease make lifelong follow-up mandatory. Genetic studies may be indicated in pheochromocytoma patients.

The clinical significance of nuclear DNA ploidy pattern in 184 patients with pheochromocytoma

Flow cytometric nuclear DNA analysis was performed on paraffin-embedded tissue samples taken from 184 patients with pheochromocytoma and paraganglioma treated between 1960 and 1987. The Hedley technique was used for measurement of nuclear DNA content. Thirty-five percent of the tumors were DNA diploid, 33% showed a DNA tetraploid pattern, and 32% had DNA aneuploid pattern. Familial pheochromocytoma and associated endocrine or neoplastic disorders were more common among patients with DNA nondiploid tumors. Eighty-four percent of the tumors that invaded blood vessels and all patients with regional or distant metastases had tumors classified as DNA tetraploid or DNA aneuploid. Of 22 patients who had disease progression, 21 (95%) had tumors with abnormal DNA ploidy pattern (P less than 0.001). All 12 patients who died of cancer-related disease had abnormal DNA ploidy; none of the patients with DNA diploid tumor (n = 64) have died of pheochromocytoma (P less than 0.01). These results suggest that nuclear DNA ploidy pattern is an important and independent prognostic variable for patients with pheochromocytoma and paraganglioma.

Sporadic unilateral adrenomedullary hyperplasia with hypertension cured by adrenalectomy

Adrenomedullary hyperplasia (AMH) with increased urinary excretion of epinephrine is regarded as the earliest adrenal manifestation in familial pheochromocytoma; however, pathogenetic mechanisms and morphogenesis involved in the development of sporadic adrenomedullary diseases are unknown as yet. We present 4 patients with clinical, biochemical, imaging, and morphological findings of sporadic unilateral adrenomedullary hyperplasia cured by unilateral adrenalectomy. All patients were hypertensive with intermittent hypertensive crises, and with increased catecholamine concentrations in urine and serum. Correct unilateral localization was achieved by 123-I-BG-scan (planar and SPECT) (n = 2) or cavovenous blood sampling with selective catheterization of both suprarenal veins (n = 2). Histomorphometric analyses revealed diffuse adrenomedullary hyperplasia in all 4 specimens with significant increase of relative volume to 17.6% (controls, 8.7%), and of estimated medullary weight to 0.95 g (controls, 0.45 g); corticomedullary ratio (C:M) was decreased to 5.4 (controls, 11.2). DNA histograms showed euploidy in all cases. In 3 patients, DNA analysis revealed evidence of cell proliferation, but without increase to grade of malignancy indices (0.101-0.523). Adrenalectomy was performed preferentially by a translumbar approach; the operative and postoperative course was uneventful in all 4 patients. Blood pressure without antihypertensive drugs returned to normal in 3 patients, in 1 patient to the upper normal limit.