Pheochromocytoma due to unilateral adrenal medullary hyperplasia

Abstract

We describe two male patients, aged 17 and 47 years, with clinical and biochemical features of pheochromocytoma. Both patients had normal-sized adrenal glands on abdominal CT scan and abnormal unilateral uptake of I-123 metaiodobenzylguanidine (MIBG) on scintigraphy. The surgical adrenalectomy revealed normal macroscopic glands in both patients. Histological examination showed adrenal medullary hyperplasia with adrenal cortico-medullary ratios of 2:1 and 4:1. Unilateral adrenalectomy resulted in amelioration of symptoms and normalization of catecholamines excretion. DNA examination for RET protooncogene revealed no mutations in exons 10, 11, 13, 14 and 16. Our results suggest that diffuse adrenal medullary hyperplasia may be the initial pathological change in the adrenal gland leading, subsequently, to the development of nodular hyperplasia and adrenal medullary tumor. These results indicate that the syndrome of pheochromocytoma may occur as an unilateral adrenal medullary hyperplasia in patients without evidence for multiple endocrine neoplasia.

Laparoscopic Adrenalectomy for Nonfamilial Adrenal Medullary Hyperplasia

“…1,9 However, approximately 20% of normal adrenals take up some 123 I-MIBG. 9 Scintigraphy in the form of MIBG scanning is slightly less sensitive but is useful in determining extra-adrenal, multifocal, or recurrent disease.…”

“…1,9 However, approximately 20% of normal adrenals take up some 123 I-MIBG. 9 Scintigraphy in the form of MIBG scanning is slightly less sensitive but is useful in determining extra-adrenal, multifocal, or recurrent disease. 7 For patients with negative 123 I-MIBG scintigraphy or patients who may have malignant pheochromocytoma, octreotide scan and FDG-PET are other options for localization.…”

The value of plasma markers for the clinical behaviour of phaeochromocytomas

“…Notably, all of these latter cases had normal urinary CAT metabolites as well, but PCCs were more or less incidentally diagnosed by CT and MIBG scans in three sporadic cases and during family screening in three MEN2 cases. In four of these six cases, tumours were smaller than 1 cm, this has been arbitrarily referred to as micronodular medullary hyperplasia, the PCC-precursing lesion in the adrenal medulla in MEN2 (35) and sporadic (36,37) cases. The following correlations of plasma markers and clinicopathological features of PCCs could be established.…”

Diagnosis of pheochromocytoma in the setting of Parkinson disease

“…1 the reported resolution of typical pheochromocytoma symptoms after surgical adrenalectomy in two patients with unilateral adrenal medullary hyperplasia suggests that pheochromo cytoma could represent an initial patho logical change that ultimately leads to formation of a tumor. 2 under normal circumstances, biochemical tests for excess of catecholamines and their metabolites form the mainstay of the initial diagnostic work-up for pheochromo cytoma. traditionally, these tests include measurements of plasma and urine catecholamines (epinephrine and norepinephrine), urine fractionated metanephrine and normetanephrine, urine vinyl mandellic acid, and plasma free metanephrines and normeta neprine.…”