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 rem oved. The tumor was 8.5 cm in greatest dimension and is thought to be the l argest such tumor reported to date. Ultrastructural study confirmed the dia gnosis of JGCT by the demonstration of the typical cytoplasmic rhomboidal s ecretory granules on electron microscopy. The tumor cells were also strongl y reactive for CD34, a finding that has not been previously reported and th at may be an adjunct to the diagnosis of JGCT in a patient with hypertensio n, hyperreninemia, and/or hypokalemia. At present, however, further studies on additional cases for CD34 expression will be necessary to fully evaluat e the diagnostic utility of this marker in the diagnosing of JGCT.