|Year : 2001 | Volume
| Issue : 2 | Page : 161-163
Extra-adrenal pheochromocytoma - a case report
Sharad H Somani, Jagdish B Bhawani, Percy Jal Chibber
Department of Urology, Sir J J Hospital, Mumbai, India
Percy Jal Chibber
Department of Urology, Sir J J Hospital, Byculla, Mumbai - 400 008
Source of Support: None, Conflict of Interest: None
Keywords: Pheochromocytoma; Extra-Adrenal.
|How to cite this article:|
Somani SH, Bhawani JB, Chibber PJ. Extra-adrenal pheochromocytoma - a case report. Indian J Urol 2001;17:161-3
| Case Report|| |
A 28-year-old female presented with headache and restlessness for 2 years and vague abdominal pain for 6 months. Investigations revealed a mass below the lower pole of the right kidney on ultrasonography. An attempt at removal of the mass was attended by severe hypertensive crisis mandating abandonment of the procedure. Patient was referred to our center for further management. On admission, her blood pressure was 220/120 mm of Hg. Urinary Vanillylmandelic acid (VMA) was 15.5 mg (normal range 2-14 mg). Computerised tomography (CT) abdomen revealed a 5-cm diameter mass below the lower edge of the right kidney near the midline with solid and cystic component and enhancement on post-contrast study. Adrenals were normal. 131 I-Metaiodobenzylguinidine (MIBG) scan revealed a single area of increased uptake at the site of the mass [Figure - 1]. With adequate preoperative preparation exploratory laparotomy was done. A mass below the lower pole of right kidney, in front of the inferior vena cava and aorta below the origin of inferior mesenteric artery was found and removed [Figure - 2]. Histology of the mass was consistent with pheochromocytoma [Figure - 3]. Patient was asymptomatic postoperatively and her blood pressure was well controlled on 25 mg atenolol orally daily. Follow-up urinary VMA was normal and MIBG scan after 3 months revealed no area of increased tracer uptake.
| Discussion|| |
Pheochromoeytoma is rare, accounting for less than 0.1 % of hypertensive population.  Extra-adrenal pheochromocytomas are rarer still (10% of all pheochromocytomas) and are usually seen in the second and third decades.  There is no sex predominance.  Extra-adrenal pheochromocytomas are often multicentric and more likely to be malignant than those of adrenal origin. 
The organ of Zuckerkandl, small collections of paraganglion tissue that lie contiguous to the aorta between the root of inferior mesenteric artery and the aortic bifurcation, were described by Emil Zuckerkandi in 1901. , The embryological origin and histology of these tissues are similar to the adrenal medulla and the tumours arising from both of them are functionally similar.  Organ of Zuckerkandl is second in frequency as a site for extra-adrenal pheochromocytoma.  These tumours are predominantly epinephrine producing as opposed to other extra-adrenal sites which are norepinephrine-producing tumours. ,
The presence of hypertension with symptoms of adrenergic excess should alert the clinician to the tumours of adrenal medulla as well as the extra-adrenal paraganglion system.  Patients with extra-adrenal pheochromocytoma commonly present with the classic triad of headache, palpitations and sweating. Sustained or paroxysmal hypertension is present in 80-100% of these patients.
Urinary estimation of catecholamines and their metabolites is a better biochemical investigation than plasma estimation for the diagnosis of these lesions.  CT scan is the imaging modality of choice for localization. , MIBG scan is indicated in extra-adrenal tumours to rule out multicentricity and metastasis. , In extra-adrenal pheochromocytomas the traditional histological markers of malignancy may not predict the malignant behavior. The diagnosis of malignancy can be made with confidence only by demonstrating tumour cells at sites where paraganglion tissue is normally absent. , Surgery after adequate preoperative preparation remains the treatment of choice. 
A lifelong follow-up is indicated, as the extra-adrenal pheochromocytomas are more likely to recur and to metastasize. Annual determination of urinary catecholamines and their metabolites is recommended. Persistent hypertension after successful removal of pheochromocytoma occurs in approximately 25% of cases. 
| References|| |
|1.||Whalen RK, Althausen AF, Daniels GH. Extra-adrenal pheochromocytoma. J Urol 1992: 147: 1-10. |
|2.||Goldfarb DA, Novick AC. Bravo L et al. Experience with extra adrenal pheochromocytorna. J Urol 1989; 142: 931-936. |
|3.||Brantigen CO, Katase RY. Clinical and pathologic features of paragangliomas of the organ of Zuckerkandl. Surgery 1969; 65: 898. |
[Figure - 1], [Figure - 2], [Figure - 3]