Endocrine Abstracts

We describe a case of cystic pheochromocytoma (PCC) with negative biochemical evaluation, diagnosed on the basis of hypertensive crises during operative management and histopathologic findings. A 57-year-old woman complained of several episodes of stabbing right upper abdominal pain accompanied by tachycardia, headache, lack of breath, elevated blood pressure and vomiting in the preceding three years. At presentation, blood investigations were significant only for mildly elevated transaminases and serum amylase. An abdominal ultrasound was performed and revealed large right adrenal incapsulated and heterogenous mass, 7 × 7 cm in size, with mass effect. Computed tomography imaging confirmed incapsulated adrenal mass with internal septations and unenhanced attenuation of >30 Hounsfield units. Based on imaging appearance and patient’s history, a suspicion of PCC was established, and the patient was referred to endocrinologist. Laboratory exams for Cushing’s syndrome were unremarkable and urinary vanilmandelic acid, metanephrines and serum chromorgranin A were within normal range on several occasions. Further evaluation with iodine-123 (123I)-labeled metaiodobenzylguanidine (MIBG) scintigraphy would have been useful to differentiate the mass, but it was not available at the moment of investigations. Despite negative biochemical diagnosis,strong clinical suspicion for PCC was established and the patient was preoperatively prepared with α-adrenoreceptor and beta blockers. Initial attempt for laparoscopic adrenelectomy was unsuccessful due to early intraoperative occurrence ofhypertensive crises with blood pressure 300/150 mmHg. Three months later a successful open adrenelectomy was performed with nonsignificant intraoperative hemodynamic instability. Histopathologic evaluationconfirmed cystic benign PCC with dominance of multnuclear giant, foamy macrophages, presence of hemosiderin deposition and hemolyzed erythrocytes. Although cystic adrenal lesions comprise several types of non-functionating benign lesions, the differential diagnosis should include cystic form of PCC, an entity that is rarely reported. In cystic PCC the number of cateholamin-producing cells are low, especially when an extensive necrotic cystic regions are present. Furthermore, catecholamines stored in the capsular mass may not be released into the blood circulation until surgical attempt for isolation of PCC is made. Therefore, high clinical suspicion for PCC is necessary since negative biochemical diagnosis is possible. As demonstrated by our case, clinical presentation was crucial in the diagnosis and preoperative management. Preoperative optimization with antihypertensive drugs and blood volume expansion fluids is obligatory in PCC surgery in order to prevent detrimental intraoperative hemodynamic instability. Albeit laparoscopic adrenelectomy is becoming a first line surgical option for PCC, still it’s not always feasible as shown in our case.