Morphology of the adrenal medulla indicating multiple neuroectodermal abnormalities in pheochromocytoma patients.

: 25 of 85 (29.4%) consecutive patients operated on for pheochromocytoma had other neuroectodermal abnormalities. Medullary thyroid carcinoma was the most common associated neuroectodermal abnormality followed by von Recklinghausen's neurofibromatosis. Other abnormalities were intracranial tumors, parathyroid hyperplasia and midgut carcinoid. The adrenal medulla was studied to find out morphological characteristics in patients with associated neuroectodermal abnormalities. All patients with multiple pheochromocytomas (n = 7) and all patients with hyperplasia of the extratumoral adrenal medulla (n = 13) had other neuroectodermal abnormalities. It is important to detect the associated neuroectodermal abnormalities because they can be lethal. Patients with associated neuroectodermal abnormalities often have hereditary syndromes.