Coexistence of Pheochromocytoma with Abdominal Aortic Aneurysm: An Untold Association
A 45-year-old woman was admitted with complaints of headache, sweating, anxiety, dizziness, nausea and vomiting. She also had dull aching abdominal pain, which was poorly localized, non-radiating and not associated with any nausea, vomiting or altered bowel habits. She was a non-smoker with no significant family history. The patient was 168 cm tall and weighed 61 kg. On physical examination, there were no cafe au lait spots or neurofibromas. Her resting pulse rate was 100 beats/min. The patient's blood pressure was 230/140 mmHg without any asymmetry between the limbs. Abdominal examination revealed mild lower abdominal tenderness without any hepatomegaly and ascitis. There was a palpable, pulsatile, expansile and non-tender mass in the epigastric region. Rest of the systemic examination was unremarkable.\nThe patient's hemogram and blood biochemistry, including potassium, sodium, bicarbonate, calcium, phosphorus, alkaline phosphatase and creatinine levels, and liver function tests were normal. The electrocardiogram revealed left ventricular hypertrophy. No alterations in cardiac as well as renal function were observed. Thus, the presence of pheochromocytoma was suspected. The endocrinological evaluation was planned to measure the levels of catecholamines, steroids and the renin-angiotensin system parameters. The catecholamines and their metabolites were measured by performing high-performance liquid chromatography–electrochemical detection by using Biorad variant D 10. Automated enzyme immunoassay was used for the assessment of plasma cortisol. Adrenocorticotropic hormone (ACTH), plasma renin activity and plasma aldosterone were estimated by radioimmunoassay methods by using the Roche E 601 analyzer. This battery of tests revealed increase in plasma metanephrines, 24-h fractionated metanephrines and VMA and supine plasma renin activity, and that plasma aldosterone concentrations were increased []. Plasma cortisol and hormone ACTH levels were within normal ranges [].\nAbdominal CT revealed a large, well-defined, heterogenous para-aortic mass (6 cm × 3 cm) with attenuation score of 35 hounsfield units (HU) at the upper pole of the right kidney without any calcification []. Further work up to establish the etiology of the abdominal pain included MRI of the abdomen, which demonstrated a 4.5 cm AAA with 3 cm lumen []. A diagnosis of right pheochromocytoma was made, and surgical treatment was recommended to her. Alfa receptor blocking therapy with prazosin was instituted, followed by β-blocker after adequate α-blockade. After 2 weeks, hypertension was well controlled and the remaining symptomatology disappeared. With adequate blood pressure control, laparoscopic adrenalectomy was performed on the patient. Light microscopy of the specimen showed characteristic organoid or zellballen nest of cells, confirming the diagnosis of pheochromocytoma, with no cytoplasmic inclusion, pleomorphism, cytological alterations or necrosis; the mitotic index was low []. Because of the asymptomatic 4.5 cm aneurysm, our patient was advised for periodic follow-up of the lesion.\nDuring the post-operative period, the blood pressure was normal and the patient's convalescence was uncomplicated. She was discharged on the 7th post-operative day. During the next 12 months, the patient's blood pressure remained normal and the size of the aneurysm did not change. A 24-h urine sample was collected for analyzing the levels of metanephrines and VMA, which were found to be within the normal ranges. At present, the patient is asymptomatic and requires no medications.