Small Pheochromocytomas: Clinical, Diagnostic and Perioperative Issues of Disease

Small Pheochromocytomas: Clinical, Diagnostic and Perioperative Issues of Disease Introduction: Pheochromocytoma (P) is considered as relatively rare adrenal tumor with clinical manifestation after reaching the size of 4-6cm. Meanwhile, it’s supposing that small P can be not rare found within different diagnostic imagination. Some of these, being clinically silent, can cause serious cardio-vascular risk undergoing unrelated medical procedures. We compared clinical course, peculiarities of diagnostics and treatment of small P (less than 3cm) and bigger P on the basement of own clinical experience among patients underwent adrenalectomy on proven or suspected P. Material and methods: Group of small P was comprised by 14 patients aged from 21 to 62 years with mean size of tumor 23mm (range: 4-29mm). Control group consisted of 35 patients corresponded on age (23-75 years) with mean P diameter of 56mm (range: 30-127mm). Small P comprised 8% of all 175 patients with P operated on during the last 19 years in endocrine surgery hospital from the whole group of 967 adrenalectomies. Prevalence of women and right side lesions characterized both groups. Discussion: Principal differences between groups were less prominent clinical activity (any symptoms were detected in half of small P) with less level of catecholamines and metanefrines in lab examination of serum and urea of small P patients. Computed tomography was often the first but not targeted diagnostic step. Silent clinical course was the main reason that small P have been discovered predominantly incidentally with no blockage of alpha-adrenergic receptors before surgery in 6 of 14 patients. Most of them had a critical elevation of blood pressure during operation (43% against 9% in control group; p<0.05). Despite small size and mild catecholamine excess in small P group, 4 from 14 patients (29%) experienced episodes of potentially harmful hypertensive crisis during unrelated medical procedures in the past. All small P were treated successfully by laparoscopic adrenalectomy. Most of patients became free from hypertension. Conclusion: Small P may carry actual risk of unexpected hypertensive crisis during any unrelated medical procedures. The clinical course of small P is hidden in half of patients and laboratory investigations are interfered with mild elevation of biochemical markers. Laparoscopic adrenalectomy is safe mode of treatment of small P in case of adequate preparation.