Humans ; Female ; Hypertension/complications* ; Kidney Neoplasms/pathology* ; Juxtaglomerular Apparatus/pathology*

Humans ; Female ; Hypertension/complications* ; Kidney Neoplasms/pathology* ; Juxtaglomerular Apparatus/pathology*

We report a case of renin-secreting juxtaglomerular cell tumor which developed in a hypertensive 47-yr-old Korean man. Presumptive clinical diagnosis was made before surgery based on the high level of plasma renin and the radiologic evidence of renal mass. Grossly, a round, bulging, well-encapsulated mass of 3x3 cm was located in the mid-portion of the right kidney. On microscopic examination, the tumor was composed of ovoid to polyhedral cells with bland nuclei, indistinct nucleoli and light eosinophilic cytoplasm. The immunostaining for renin showed strong positivity in the cytoplasm of tumor cells. The characteristic rhomboid shaped renin protogranules were observed in ultrastructural analysis.
Human ; Hypertension, Renal/*etiology/pathology ; Juxtaglomerular Apparatus/*pathology ; Kidney Neoplasms/*complications/*pathology/secretion ; Male ; Middle Age ; Renin/blood/secretion

OBJECTIVETo study the morphologic characteristics and immunophenotype of juxtaglomerular cell tumor of the kidney (JGCT), with discussion on its diagnostic clues and possible histogenesis.

METHODSThe clinical, pathologic and immunohistochemical features of 5 cases of JGCT were evaluated. In addition, 5 cases of hemangiopericytoma and 5 cases of cutaneous glomus tumor were selected for comparative immunohistochemical analysis.

RESULTSThe JGCT cases came from 4 females and 1 male (mean age at diagnosis = 32 years). All of them manifested symptoms of systemic hypertension. Four of the patients received partial nephrectomy and the remaining patient was treated by radial nephrectomy. All of them were followed up for a period of 4 to 66 months (average = 27 months). There was no evidence of local recurrence or distant metastases. On gross examination, these JGCTs were well-circumscribed and situated in the renal cortex and measured 4.4 cm in greatest dimension on average. Histologically, the tumor was characterized by the following three features: (1) solid sheets of relatively uniform polygonal to round cells with lightly eosinophilic cytoplasm, sometimes containing PAS-positive intracytoplasmic granules; (2) absence of or very scanty mitotic figures; (3) interstitium rich in thin-walled capillaries, associated with focal hyaline change and hemangiopericytoma-like architectural pattern. Under electron microscopy, characteristic rhomboid-shaped renin granules were found in the cytoplasm. All JGCTs were immunoreactive for renin, CD34, actin, and calponin. In contrast, all glomus tumors were negative for renin and all hemangiopericytomas were negative for actin.

CONCLUSIONSJGCT is a rare benign renal neoplasm typically found in young adults and manifests as systemic hypertension. The tumor cells may be originated from modified vascular smooth muscle cells. The identification of renin granules by electron microscopy and demonstration of the characteristic immunophenotype is the key to correct pathologic diagnosis.

Adult ; Antigens, CD34 ; analysis ; Calcium-Binding Proteins ; analysis ; Female ; Humans ; Immunohistochemistry ; Juxtaglomerular Apparatus ; chemistry ; pathology ; ultrastructure ; Keratins ; analysis ; Kidney Neoplasms ; pathology ; Male ; Microfilament Proteins ; Microscopy, Electron ; Middle Aged

Actins ; metabolism ; Adult ; Antigens, CD34 ; metabolism ; Diagnosis, Differential ; Female ; Follow-Up Studies ; Humans ; Hypertension ; etiology ; Juxtaglomerular Apparatus ; pathology ; surgery ; ultrastructure ; Kidney Neoplasms ; complications ; metabolism ; pathology ; surgery ; ultrastructure ; Nephrectomy ; Vimentin ; metabolism

OBJECTIVETo investigate the clinical characteristics, morphologic and immunohistochemical features, diagnosis, differential diagnosis, histogenesis and prognosis of renal juxtaglomerular cell tumor (JGCT).

METHODSLight microscopic observation; immunohistochemical assay of CK8, E-cadherin/CK7, CD10, Vim, Actin, CD34, S100, HMB45, CD31, Chr, Syn and CD117, EM; and follow-up were done on all 4 surgically treated JGCT patients.

RESULTSAll 4 JGCT were observed in young adult with clinically uncontrolled severe hypertension. Grossly, the tumor was encapsulated and small in size. Microscopically, the tumor cells grew in sheets predominantly, but papillary and onion-like pattern could also be seen. The stroma contained prominent vasculature that consisted of numerous thin-wall vessels clustering around thick-walled vessels. Tumor cells were rather small, polygonal, with slightly eosinophilic cytoplasm and ill-defined cell border. Nuclei were uniform in size but nuclear atypia and mitosis could be seen. Numerous mast cells were scattered among the tumor cells, and tubules were identified in 3 of 4 cases with positive expression of distal tubule marker of E-cadherin/CK7. Tumor cells positively expressed Vim, Actin, calponin, and CD34. All cases presented ultrastructural features of distinct rhomboid-shaped crystal. There was no recurrence or metastasis but hypertension persisted in three during follow-up (mean 37 months) for all 4 JGCT patients.

CONCLUSIONJGCT, originating from the juxtaglomerular cell, has a distinct benign entity, and it is typically found in young adults with severe hypertension. It has a unique morphology and ultrastructure features and positive immunoreactivity to Vim, Actin, calponin and CD34.

Actins ; analysis ; Adolescent ; Adult ; Antigens, CD34 ; analysis ; Calcium-Binding Proteins ; analysis ; Female ; Humans ; Hypertension ; etiology ; Immunohistochemistry ; Juxtaglomerular Apparatus ; chemistry ; pathology ; ultrastructure ; Kidney Neoplasms ; chemistry ; pathology ; ultrastructure ; Male ; Microfilament Proteins ; analysis

Actins ; metabolism ; Adult ; Antigens, CD34 ; metabolism ; Carcinoma, Renal Cell ; metabolism ; pathology ; Diagnosis, Differential ; Female ; Glomus Tumor ; metabolism ; pathology ; Hemangiopericytoma ; metabolism ; pathology ; Humans ; Hypertension ; etiology ; Juxtaglomerular Apparatus ; metabolism ; pathology ; surgery ; ultrastructure ; Kidney Neoplasms ; complications ; metabolism ; pathology ; surgery ; ultrastructure ; Nephrectomy ; Wilms Tumor ; metabolism ; pathology