Metastatic Juxtaglomerular Cell Tumor in a 52-Year-Old Man

Abstract

Juxtaglomerular cell tumor is a rare renal neoplasm arising from the juxtaglomerular apparatus. Approximately 70 cases have been reported in the English literature since it was first described by Robertson et al in 1967. This tumor has been considered benign and resection has so far been curative. In this paper, we report the first metastatic juxtaglomerular cell tumor. The 15-cm tumor occurred in the right kidney of a 46-year-old man. It invaded the renal vein, and was treated by radical nephrectomy in 1995. The diagnosis at that time was renal cell carcinoma. The patient was well for 6 years and then developed bilateral lung masses, which were resected. Microscopically, the tumors from the kidney and the lungs were similar, consisting of solid sheets of uniformly round-to-polygonal cells intermixed with abundant delicate vasculature. Both renal and pulmonary tumors were positive for vimentin, renin, and only focally to CD34. Electron microscopic studies performed on the paraffin-embedded renal tumor and formalin-fixed lung tumor revealed the typical rhomboid crystals of proto-renin. In consideration of the characteristic morphologic features, immunohistochemistry, and the presence of rhomboid crystals of proto-renin, the diagnosis was modified to malignant juxtaglomerular cell tumor.

Chromosome abnormalities in juxtaglomerular cell tumors

“…The same IP-FISH analyses performed on Tumor 1 confirmed the finding of a hypotriploid karyotype with many numerical aberrations. Many of the examined chromosomes (3,5,7,8,12, and 18) were trisomic in Tumor 1, although all of them also showed a relatively large disomic clone, as was also true for the nondisomic chromosomes in Tumor 2, possibly representing cytogenetically normal stromal cells. This reasoning also applies to chromosomes 10 and 20 for which predominantly tetrasomic clones were found together with smaller disomic clones.…”

“…19 The immunohistochemical findings with positive staining for vimentin and CD34, focally positive staining for SMA, but no staining for CK, CD31, and actin, are also typical, as are the rhomboid and crystalloid granules that were found by electron microscopy. Although JGCTs are classified as benign tumors, 19 there have been reports of metastasis 7 as well as a reninoma-associated death. 6 For these reasons, we believe that a (cyto)genetic characterization of these tumors might prove to be of clinical interest in addition to the academic interest centered around the elucidation of the pathogenetic mechanisms involved.…”

“…6 Recently, a malignant JGCT was described. 7 To our knowledge, no reports to date have addressed the genomic features of reninomas. In the current study, we describe the first karyotype of a reninoma together with molecular genetic characterization by comparative genomic hybridization (CGH) and interphase fluorescence in situ hybridization (IP-FISH) of the same tumor as well as of another reninoma.…”

Arsenic trioxide inhibits growth of As4.1 juxtaglomerular cells via cell cycle arrest and caspase-independent apoptosis

“…Hypertension is a sign in almost all patients, and laboratory findings of hyperreninemia, hyperaldosteronism, and hypokalemia are characteristic. A malignant juxtaglomerular cell tumor was recently described (11). It has been speculated that the kidney and juxtaglomerular apparatus (JGA) contain a ROS-generating system that is responsive to angiotensin II (46,47).…”

Juxtaglomerular Cell Tumor that was Preoperatively Diagnosed Using Selective Renal Venous Sampling

“…JCTs primarily affect adolescents and young adults, with a peak prevalence in the second and third decades of life, and are twice as common in women (8,13). All of the reported JCTs have been benign tumors, except for two cases (4,14). However, the clinical behavior of these lesions can be malignant as a result of severe systemic complications of hypertension.…”