Juxtaglomerular cell tumor of the kidney: Case report with immunohistochemical and electron microscopic investigations and review of the literature

We present a case of juxtaglomerular cell tumor (JGCT) that developed in a 44-year-old woman with hypertension, which subsided after the tumor was removed. The tumor was 8.5 cm in greatest dimension and is thought to be the largest such tumor reported to date. Ultrastructural study confirmed the diagnosis of JGCT by the demonstration of the typical cytoplasmic rhomboidal secretory granules on electron microscopy. The tumor cells were also strongly reactive for CD34, a finding that has not been previously reported and that may be an adjunct to the diagnosis of JGCT in a patient with hypertension, hyperreninemia, and/or hypokalemia. At present, however, further studies on additional cases for CD34 expression will be necessary to fully evaluate the diagnostic utility of this marker in the diagnosing of JGCT.