Juxtaglomerular cell tumor

Juxtaglomerular cell tumor (JGCT) is a rare neoplasm originating from the juxtaglomerular cells of the kidney. These cells are primarily involved in the regulation of blood pressure through the renin-angiotensin system. JGCT is most commonly diagnosed in young adults and is characterized by its potential to produce excessive amounts of renin, leading to secondary hypertension and hyperaldosteronism.

Etiology and Pathogenesis

The exact cause of JGCT remains unknown. However, it is believed to arise from the juxtaglomerular cells, which are specialized smooth muscle cells located in the walls of the afferent arterioles of the kidney. These cells play a crucial role in the regulation of blood pressure by secreting renin, a key enzyme in the renin-angiotensin-aldosterone system (RAAS).

Clinical Presentation

Patients with JGCT typically present with symptoms related to hypertension and hyperaldosteronism. These may include headache, fatigue, visual disturbances, and in severe cases, end-organ damage. Due to the tumor's excessive renin production, patients may also exhibit symptoms of hypokalemia such as muscle weakness and cramps.

Diagnosis

The diagnosis of JGCT involves a combination of clinical evaluation, laboratory tests, and imaging studies. Laboratory tests may reveal elevated plasma renin activity and aldosterone levels. Imaging studies, such as ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI), are used to locate the tumor within the kidney.

Treatment

The primary treatment for JGCT is surgical removal of the tumor. Nephron-sparing surgery is preferred to preserve kidney function, especially in cases where the tumor is localized and the kidney's structure allows for partial resection. In some cases, antihypertensive medications may be required to manage blood pressure before and after surgery.

Prognosis

The prognosis for patients with JGCT is generally favorable following successful surgical removal of the tumor. Most patients experience a significant improvement in blood pressure and a decrease in renin and aldosterone levels postoperatively. Long-term follow-up is recommended to monitor for recurrence or the development of chronic kidney disease.

Epidemiology

JGCT is a rare entity, accounting for less than 1% of all kidney tumors. It has a slight predilection for females and is most commonly diagnosed in young adults, although cases have been reported across a wide age range.

NIH genetic and rare disease info

• NIH info on Juxtaglomerular cell tumor

Juxtaglomerular cell tumor is a rare disease.