Review of juxtaglomerular cell tumor with focus on pathobiological aspect

Juxtaglomerular cell tumor (JGCT) is a very rare cause of hypertension that was first described by Robertson et al. in 1967 and the name was coined by Kihara in 1968 [1,2]. To date, approximately 100 cases with JGCT have been reported. Clinically, this tumor is characterized by hypertension, hyperaldosteronism and hypokalemia secondary to excessive renin secretion by tumor cells [3-8]. In this article, we introduce the general overview of JGCT with focus on pathobiological aspects.This tumor affects adolescents and young adults, with peak prevalence in the second and third decades of life with a female predominance [8-10]. Haab et al. (1995) detected eight JGCTs among 30,000 patients at a hypertensive clinic [11].Patients with JGCT present with various symptoms including headaches, retinopathy, double vision, dizziness, nausea, vomiting, polyuria and proteinuria [8,12]. Most of these symptoms may be attributed to hypertension or hypokalemia. Clinically, JGCT is subdivided into three categories [13]. The typical variant, which accounts for the majority of JGCT, has characteristically high renin concentration, hyperaldosteronism, hypokalemia and hypertension [4,5]. Second most common presentation is the atypical variant showing hypertension with normal potassium level [8]. The third, non-functioning variant is very rare and is characterized by a normal blood pressure and normal potassium level [14-16]. Clinicians should strongly suspect JGCT if they encounter adolescent or young adult patients with severe or even moderate hypertension associated with an unexplained secondary hyperaldosteronism [6]. JGCT may cause malignant hypertension [17]. A case of JGCT associated with membranous glomerulonephritis was also reported [18].Ultrasonography of the kidneys usually shows a hypoechoic mass [19,20]. Computed tomography (CT) scan is very useful for the detection of renal tumor, even when other imaging analyses is negative [8,21]. CT scan shows finding of low, low-to iso- or