Juxtaglomerular cell tumor of kidney with CD34 and CD117 immunoreactivity: report of 5 cases

Molecular Characterization of Juxtaglomerular Cell Tumors: Evidence of Alterations in MAPK-RAS Pathway

Juxtaglomerular cell tumor (JGCT) is a rare neoplasm, part of the family of mesenchymal tumors of the kidney. Although the pathophysiological and clinical correlates of JGCT are well known, as these tumors are an important cause of early-onset arterial hypertension refractory to medical treatment, their molecular background is unknown, with only few small studies investigating their karyotype. Herein we describe a multi-institutional cohort of JGCTs diagnosed by experienced genitourinary pathologists, evaluating clinical presentation and outcome, morphologic diversity, and, importantly, the molecular features. Ten JGCTs were collected from 9 institutions, studied by immunohistochemistry, and submitted to whole exome sequencing. Our findings highlight the morphologic heterogeneity of JGCT, which can mimic several kidney tumor entities. Three cases showed concerning histologic features, but the patient course was unremarkable, which suggests that morphologic evaluation alone cannot reliably predict the clinical behavior. Gain-of-function variants in RAS GTPases were detected in JGCTs, with no evidence of additional recurrent genomic alterations. In conclusion, we present the largest series of JGCT characterized by whole exome sequencing, highlighting the putative role of the MAPK-RAS pathway.

Clinical features, laboratory findings and treatment of juxtaglomerular cell tumors: a systemic review

Juxtaglomerular cell tumors (JGCTs) or reninoma are rare kidney tumors leading to secondary hypertension, and the non-specific clinical manifestations bring about challenges to the diagnosis. This study is to summarize the clinical features, laboratory findings, and treatment of JGCTs. The PubMed, EMBASE database, and manual search were utilized to find all cases, and 158 reports containing 261 patients were identified. Data on patients' demographics, clinical features, diagnostic methods, and treatment options were collected and analyzed. JGCTs occurred predominantly in female patients (female to male ratio, 2.1:1). The median age of patients was 25 years (IQR:18-34 years). Hypertension (97.24%) was the cardinal manifestation. Hypokalemia was reported in 78.71% (159/202) of subjects, and normal serum potassium accounted for 20.79% (42/202). In cases with assessed plasma renin activity (PRA) levels, the median PRA was 7.89 times the upper limit of normal (IQR:3.58-14.41), and 3.82% (5/131) of cases in the normal range. Tumors were detected in 97.8% (175/179) computed tomography (CT), 94.7% (72/76) magnetic resonance imaging (MRI), and 81.5% (110/135) ultrasound, respectively. For 250/261 patients undergoing surgical procedures, 89.14% (197/221), 94.94% (150/158), and 100% (131/131) of patients were restored to normal blood pressure, PRA, and serum potassium, respectively. JGCTs are commonly associated with hypertension, hypokalemia, and hyperreninemia, whereas patients with normotension, normokalemia, and PRA should be systematically pursued after drug-elution lasting for 2 weeks. CT and MRI are more sensitive imaging diagnostic methods. The blood pressure and biochemical parameters of most patients returned to normal after surgery.

Approach to the Patient: Reninoma

A reninoma is a functional tumor of afferent arteriolar juxtaglomerular cells that secretes the enzyme renin, leading to hyperactivation of the renin-angiotensin-aldosterone system. Reninoma is a potentially curable cause of pathological secondary hyperaldosteronism that results in often severe hypertension and hypokalemia. The lack of suppression of plasma renin contrasts sharply with the much more common primary aldosteronism, but diagnosis is often prompted by screening for that condition. The major differential diagnosis of reninoma is renovascular hypertension. Fewer than 200 cases of reninoma have been described. Reninomas have been reported across a broad demographic but have a 2:1 predilection for women, often of childbearing age. Aldosterone receptor blockade, angiotensin-converting enzyme inhibitors, or angiotensin receptor blockers offer effective medical management but are contraindicated in pregnancy, so surgical curative resection is ideal. The current optimal imaging and biochemical workup of reninoma and management approach (ideally, tumor excision with subtotal renal resection) are described.

Pregnancy complicated by juxtaglomerular cell tumor of the kidney: A case report

BACKGROUND

Juxtaglomerular cell tumor (JGCT) of the kidney, also known as reninoma, is a rare renal tumor that typically clinically manifests as hypertension, hypokalemia, high renin, and high aldosterone. It is a cause of secondary hypertension. Pregnancy with JGCT is rarer and easily misdiagnosed as pregnancy-induced hypertension, thus affecting treatment.

CASE SUMMARY

A 28-year-old woman presented in early pregnancy with hypertension (blood pressure of 229/159 mmHg), nausea, and occasional dizziness and headache. The patient was diagnosed with pregnancy-induced hypertension, and no relief was found after symptomatic treatment; hence, the pregnancy was terminated by artificial abortion. Her blood pressure remained high following termination of pregnancy. Blood tests suggested hypokalemia (2.997 mmol/L), blood aldosterone measured 613 ng/L, and computed tomography urography showed a tumor in the right kidney. Therefore, laparoscopic partial nephrectomy was performed. After surgery, the patient’s blood pressure returned to normal, and blood potassium, aldosterone, and renin normalized. Postoperative pathological examination revealed JGCT. After long-term follow-up, the patient became pregnant again 6 mo after surgery. No hypertension occurred during pregnancy, and the patient delivered a healthy female neonate.

CONCLUSION

Patients with pregnancy complicated by JGCT are difficult to diagnose. Herein, we advise surgeons on proper handling of such situations.

Juxtaglomerular cell tumor: report of a case with unusual presentation

Juxtaglomerular cell tumor is a benign, renin-secreting neoplasm. The tumor arises from the juxtaglomerular apparatus cells of the kidney. Because the tumor is hormonally active, patients usually suffer from hypokalemia, hyperaldosteronism, and hypertension. Herein, we describe a case of a 19-year-old Asian female with a somewhat unusual presentation.

A 19-year-old Asian female presented with upper extremity weakness, numbness, and tingling. On physical examination, the only notable finding was hypertension. Extensive workup revealed elevated aldosterone level and plasma renin activity. CT scan of the abdomen revealed a 2.2 cm mass in the lower pole of the left kidney. The mass was resected by partial nephrectomy. On microscopic evaluation, the tumor had glomoid appearance with sheets of uniform, round to polygonal cells with clear to eosinophilic cytoplasm. Immunohistochemical stains showed the tumor cells to be positive for CD117, CD34 and CD10 and negative for ER, PR, CK7, PAX-8, pan-cytokeratin, EMA, S100, Melan-A, HMB45, SMA and CAIX. Diagnosis of Juxtaglomerular cell tumor was rendered. This case highlights the importance of a regular physical exam and a high index of suspicion in patients presenting with unusual complaints.

Immunohistochemical Expression of Renin & GATA3 Help Distinguish Juxtaglomerular Cell Tumors from Renal Glomus Tumors

Juxtaglomerular cell tumors and glomus tumors both arise from perivascular mesenchymal cells. Juxtaglomerular cells are specialized renin-secreting myoendocrine cells in the afferent arterioles adjacent to glomeruli, and juxtaglomerular tumors derived from these cells are therefore unique to the kidney. In contrast, glomus tumors have been described at numerous anatomic sites and may show significant morphologic and immunophenotypic overlap with juxtaglomerular tumors when occurring in the kidney. While ultrastructural studies and immunohistochemistry for renin may distinguish these entities, these diagnostic modalities are often unavailable in routine clinical practice. Herein, we studied the clinicopathologic features of a large series of juxtaglomerular tumors (n=15) and glomus tumors of the kidney (n=9) to identify features helpful in their separation, including immunohistochemistry for smooth muscle actin (SMA), CD34, collagen IV, CD117, GATA3, synaptophysin, and renin. Markers such as SMA (juxtaglomerular tumors: 12/13, 92%; glomus tumors: 9/9, 100%), CD34 (juxtaglomerular tumors: 14/14, 100%; glomus tumors: 7/9, 78%), and collagen IV (juxtaglomerular tumors: 5/6, 83%; glomus tumors: 3/3, 100%) were not helpful in separating these entities. In contrast to prior reports, all juxtaglomerular tumors were CD117 negative (0/12, 0%), as were glomus tumors (0/5, 0%). Our results show that juxtaglomerular tumors have a younger age at presentation (median age: 27), female predilection, and frequently exhibit diffuse positivity for renin (10/10, 100%) and GATA3 (7/9, 78%), in contrast to glomus tumors (median age: 51 years; renin: 0/6, 0%; GATA3: 0/6, 0%). These findings may be helpful in distinguishing these tumors when they exhibit significant morphologic overlap.

Spindle Cell Hemangioma and Atypically Localized Juxtaglomerular Cell Tumor in a Patient with Hereditary BRIP1 Mutation: A Case Report

Spindle cell hemangioma is a benign vascular tumor typically occurring in the dermis or subcutis of distal extremities as red-brown lesions that can grow in both size and number over time. They can be very painful and potentially disabling. A family history of cancer or previous history may be relevant and must be taken into consideration. Juxtaglomerular cell tumor (reninoma) is an extremely rare cause of secondary hypertension diagnosed mostly among adolescents and young adults. Excessive renin secretion results in secondary hyperaldosteronism. Subsequent hypokalemia and metabolic alkalosis, together with high blood pressure, are clues for clinical diagnosis. Histological examination of the excised tumor leads to a definitive diagnosis. Reninoma is found in subcapsular localization, in most cases as a solitary mass, in imaging studies of kidneys. Exceptionally, it can be located in another part of a kidney. Both spindle cell hemangioma and reninoma are extremely rare tumors in children and adolescents. Herein, the authors present a case report of a patient with hereditary BRCA1 interacting protein C-terminal helicase 1 (BRIP1) mutation, spindle cell hemangioma, and secondary hypertension caused by atypically localized reninoma.

Juxtaglomerular cell tumor: Clinicopathologic evaluation in a large series emphasizing its broad histologic spectrum

The juxtaglomerular cell tumor (JCT) is a rare renal tumor. We re-evaluated the clinicopathologic features of 21 JCTs to summarize their variable morphologies. Immunohistochemical, fluorescent in situ hybridization and periodic acid-Schiff stains were routinely performed, and four JCT cases were detected via transmission electron microscopy. The 21 JCTs involved five males and 16 females, ranging in age from 19 years to 69 years (mean, 36.9 years; median, 34 years). The tumors were composed of large, small, or spindle cells with a round, oval or polygonal shape, arranged in various growth patterns. Both necrosis (1/21) and mitosis (2/21, with 1/50HFP, 8/50HFP) was rarely appreciated. All cases were immunoreactive for renin and CD34 (21/21), and few were positive for α-SMA (13/21;11/21, focally; 2/21, diffusely,), CD117 (9/21, focally) and synaptophysin (3/21, focally). Ultrastructurally, all four cases exhibited secretory granules in varying sizes in the cytoplasm, two of which exhibited cellular junctions. Almost all cases (20/21) had a favorable prognosis, but one succumbed due to bone and hepatic metastases, which corresponds to malignant JCT. Our study demonstrates that JCTs may have atypical clinical presentations and variable histologic appearances. A familiarity with these features may contribute to a correct diagnosis.

JUXTAGLOMERULAR CELL CAUSE OF SECONDARY HYPERTENSION IN AN ADOLESCENT

Reninoma (juxtaglomerular cell tumor) is a rare cause of renin-mediated hypertension. We reported a 18 year old woman with history of hypertension for 3 years. Laboratory findings showed severe hypokalemia and markedly increased levels of renin and aldosterone. Kidney ultrasonography, abdominal computed tomography and magnetic resonance imaging revealed a small mass in the middle region of the right kidney. The patient underwent nephron-sparing surgery; immunohistochemical results demonstrated typical features of reninoma. Postoperatively, blood pressure and potassium levels were normal at 1 month follow-up.

Juxtaglomerular Cell Tumor With Atypical Pathological Features: Report of a Case and Review of Literature

Juxtaglomerular cell tumor (JGCT) is a rare renal tumor with a predominantly benign clinical course. It affects young adults, who often present with hypertension, hypokalemia, and hyperaldosteronism. The tumor cells are round to spindle-shaped with occasional mild to moderate atypia, but mitotic figures are usually absent. Surgical resection is the treatment of choice. Typically, the blood pressure and renin levels normalize after removal of the tumor. Rare cases of metastatic and recurrent JGCT have been reported including cases with vascular invasion. These cases typically occur in older adults and present with larger tumor size (9-15 cm). We report a case of JGCT, 5.5 cm in greatest dimension, with atypical pathological features including invasion of the renal vein, lymphovascular invasion, and significant pleomorphism with rhabdoid morphology, along with a brief review of the literature.

Minimally Invasive Surgery-Based Multidisciplinary Clinical Management of Reninoma: A Single-Center Study

Background

This article presents our experience in managing a rare kidney tumor – reninoma – by analyzing a relatively large series of cases from a single center.

Material/Methods

Nine cases of reninoma were reviewed. Clinical manifestations, imaging examinations, laboratory examinations, perioperative data, and pathological findings were summarized. A 58.8-month follow-up was performed to evaluate patient survival and recrudescence.

Results

The main clinical manifestations were hypertension, hypokalemia, headache, dizziness, nausea, vomiting, palpation, and sweating. Three patients had hypertensive end-organ damage, including brain hemorrhage, gestation termination, and grade III ocular fundus changes. All patients underwent retroperitoneal laparoscopic partial nephrectomy successfully. The mean warm ischemic time was 23.4 min. The median operation time was 95.1 min, with a median estimated blood loss of 60 ml. The median hospital stay was 6 days. No serious intraoperative or postoperative complications occurred. The histology and electron microscopy findings confirmed the diagnosis of reninoma in all cases. After 58.8 months of follow-up, symptoms involving hypertension were relieved in all patients, and no tumor recurrence or metastasis was detected.

Conclusions

Reninoma may have severe consequences despite being a benign tumor. Retroperitoneal laparoscopic partial nephrectomy is a feasible and effective method for the surgical removal of reninoma. Multidisciplinary cooperation plays an important role in improving the diagnosis and enabling the early surgical treatment of reninoma. Especially in cases of reninoma with moderate and high RENAL scores, an accurate diagnosis of reninoma based on multidisciplinary cooperation facilitates the selection of less invasive surgical approaches.

Juxtaglomerular cell tumor: Clinical and immunohistochemical features

Juxtaglomerular cell tumor (JGCT) is a rare tumor, with approximately 100 cases reported in the literature. The authors respectively studied the clinical data of 11 patients diagnosed with JGCT in Peking Union Medical College Hospital from 2004 to 2014, and investigated the immunohistochemical profiles in 10 tumors. Nine of the 11 patients were diagnosed before the age of 40 years. Hypertension was present in all patients, while hypokalemia occurred in seven of 11 patients. Computed tomography detected JGCTs with a sensitivity of 100%. Immunoreactivities for CD34 and vascular endothelial growth factor were observed in most tumor specimens, suggesting that JGCTs express a variety of vessel-related immunohistochemical markers, although JGCTs are considered a tumor without abundant blood supply. Nuclear accumulation of cyclin D1 was common in JGCTs. Results from immunohistochemistry were negative for BRAF, HER2, and TFE3, suggesting that BRAF, HER2, and TFE3 genes might not play a part in tumorigenesis in JGCTs.

Topics in histopathology of sweat gland and sebaceous neoplasms

This article reviews several topics regarding sweat gland and sebaceous neoplasms. First, the clinicopathological characteristics of poroid neoplasms are summarized. It was recently reported that one-fourth of poroid neoplasms are composite tumors and one-fourth are apocrine type lesions. Recent progress in the immunohistochemical diagnosis of sweat gland neoplasms is also reviewed. CD117 can help to distinguish sweat gland or sebaceous tumors from other non-Merkel cell epithelial tumors of the skin. For immunohistochemical differential diagnosis between sweat gland carcinoma (SGC) other than primary cutanesous apocrine carcinoma and skin metastasis of breast carcinoma (SMBC), a panel of antibodies may be useful, including p63 (SGC⁺ , SMBC^- ), CK5/6 (SGC⁺ , SMBC^- ), podoplanin (SGC⁺ , SMBC^- ) and mammaglobin (SGC^- , SMBC⁺ ). Comparison of antibodies used for immunohistochemical diagnosis of sebaceous carcinoma (SC) suggests that adipophilin has the highest sensitivity and specificity. Some authors have found that immunostaining for survivin, androgen receptor and ZEB2/SIP1 has prognostic value for ocular SC, but not extraocular SC. In situ SC is rare, especially extraocular SC, but there have been several recent reports that actinic keratosis and Bowen's disease are the source of invasive SC. Finally, based on recent reports, classification of sebaceous neoplasms into three categories is proposed, which are sebaceoma (a benign neoplasm with well-defined architecture and no atypia), borderline sebaceous neoplasm (low-grade SC; an intermediate tumor with well-defined architecture and nuclear atypia) and SC (a malignant tumor with invasive growth and evident nuclear atypia).

Reninoma coexisting with adrenal adenoma during pregnancy: A case report

Reninoma is a rare form of secondary hypertension. The present study reported a case of reninoma that coexisted with an adrenal adenoma in a young female with secondary hypertension during pregnancy. The patient, a 31-year-old female exhibiting hypertension for >1 year, developed a mass in the right adrenal gland, which was detected by an ultrasound scan in the 33rd gestational week. In addition, a well-defined solid mass on the left kidney was detected by a magnetic resonance imaging scan1 month subsequent to the termination of the pregnancy. The blood pressure (BP) of the patient did not change subsequent to the laparoscopic right adrenalectomy. The patient subsequently underwent laparoscopic left partial nephrectomy 2 months later. The BP levels demonstrated a significant reduction from 177/115 to 125/80 mmHg in the same day postoperatively, and stabilized to be within the normal range. The BP level of the patient remained within the normal range subsequent to a 6-month follow-up. Pathological analysis revealed reninoma on the left kidney. The present study aimed to provide information for radiologists who may encounter this type of benign tumor in the future, which exhibits elevated BP levels.

Presence of Mast Cells and Mast Cell Degranulation in Scalp Biopsies of Telogen Effluvium

BACKGROUND

Telogen effluvium (TE) is a type of acquired, diffuse alopecia that occurs due to an abnormal shift of scalp hair follicles from anagen to telogen, leading to premature shedding of hair. Previous studies have suggested the existence of a neuroimmunologic "brain-hair follicle" axis, in which mast cells have been implicated as an important link between the nervous system and immunologic system.

OBJECTIVE

The current study sought to investigate the role of mast cell presence and mast cell degranulation in the pathogenesis of TE.

MATERIALS AND METHODS

Mast cells were counted using Giemsa and tryptase immunohistochemical stains in scalp biopsy specimens with the pathologic diagnosis of TE (TE, n = 10), alopecia areata (AA, n = 7), and androgenic alopecia (ANDRO, n = 9).

RESULTS

We found significant (P < 0.001) group-level differences between the mean mast cell counts per high-power fields for each type of alopecia studied. Tukey post hoc analysis showed the mean mast cell count for TE to be significantly larger than AA for both Giemsa (P = 0.002) and tryptase (P = 0.006); significantly larger than ANDRO for both Giemsa (P < 0.001) and tryptase (P < 0.001); and significantly larger when compared to normal scalp skin for both Giemsa (P < 0.001) and tryptase (P < 0.001). No significant difference of mean mast cell counts was observed for AA compared to ANDRO for Giemsa (P = 0.373) or tryptase (P = 0.598) stains.

CONCLUSION

Our findings suggest that mast cells could play a role in mediating stress-induced hair loss seen in TE.

Preoperative Diagnosis of Juxtaglomerular Cell Tumors in Eight Patients

The aim of this study was to improve the diagnostic efficiency for juxtaglomerular cell tumors (JCTs) and to determine whether clinical and magnetic resonance imaging features can help to differentiate JCTs from clear cell renal cell carcinoma (ccRCC). The clinical features of eight patients with JCTs and 27 patients with ccRCCs were analyzed. A flow diagram for young people with hypertension was applied to facilitate the diagnosis. Clinical presentations were analyzed, including age, hypertension, and hypokalemia. The results of our study produced a flow diagram that narrowed the scope of diagnosis. The statistical results demonstrated that patients with a renal mass aged 14 to 30 years, had grade 3 hypertension, or had moderate hypokalemia had a greater possibility of having a JCT than a ccRCC (P<.0000, P<.01, P<.0005, respectively). In addition, the flow diagram and magnetic resonance imaging features were useful to distinguish JCTs from other renal tumors.

A Rare Cause of Secondary Hypertension in A Young Adult

Reninoma is a rare, renin-secreting, benign renal neoplasm that can cause secondary hypertension. We report a case of a 21-year-old man who suffered from progressively worsening headache for 2 months with a history of hypertension for 7 years. Laboratory studies showed normal potassium level, increased basal plasma renin activity, and normal serum aldosterone level. Abdominal computed tomography and magnetic resonance imaging revealed a small mass in the middle region of the right kidney. Partial nephrectomy was performed; immunohistochemical results demonstrated typical features of reninoma. Postoperatively, blood pressure and potassium level were normal at the 2-month follow-up.

Focal Segmental Glomerulosclerosis Secondary to Juxtaglomerular Cell Tumor during Pregnancy: A Case Report

Juxtaglomerular cell tumor is a rare renal neoplasm. Secondary hypertension with juxtaglomerular cell tumor can be seen in females in their 20s and 30s. We present a case of juxtaglomerular cell tumor during pregnancy. A 32-year-old female was hospitalized for refractory hypertension and nephrotic syndrome in the 23rd gestational week. One year before admission, she had been diagnosed with hypertension; plasma renin activity at that time had been 2.3 ng/ml/h. Her blood pressure was uncontrolled during pregnancy, and proteinuria was detected in the 12th gestational week despite the administration of antihypertensive medications. Laboratory data showed proteinuria, hypokalemia, and hypoalbuminemia. In the 25th gestational week, she underwent surgical termination of the pregnancy because of congestive heart failure and acute renal injury. After the termination of the pregnancy and the delivery of a viable fetus, her hypertension and nephrotic syndrome were found to persist with a high plasma renin activity (13 ng/ml/h). Ultrasonography showed a 5.5-cm left renal cystic mass with a partially solid component at the lower renal pole. The left kidney with the renal mass was excised by laparoscopic nephrectomy. Plasma renin activity normalized the next day, with a decrease in blood pressure to 120–130/80–90 mm Hg; however, proteinuria remained at ≥3.5 g/day. On the basis of histopathological findings, the patient was diagnosed with a juxtaglomerular cell tumor and focal segmental glomerulosclerosis. Juxtaglomerular cell tumor is a rare renin-secreting tumor associated with refractory hypertension in young females and is a possible cause of hypertension during pregnancy.

Recurrent malignant juxtaglomerular cell tumor: A rare cause of malignant hypertension in a child

A juxtaglomerular cell tumor or reninoma is a very rare renin-secreting tumor of the kidney and can be an unusual cause of secondary hypertension. We report a case of recurrence of this uncommon tumor at the hilum of left kidney in an 8-year-old male child.

Juxtaglomerular cell tumor: a morphological, immunohistochemical and genetic study of six cases

Juxtaglomerular cell tumors (JGCTs) are rare tumors characterized by renin synthesis, hyperaldosteronism and hypertension. A curious immunohistochemical overlap between JGCT and gastrointestinal stromal tumor (GIST) including the expression of vimentin, CD34, CD117, α-smooth muscle actin was previously reported, prompting us to further investigate JGCT and its phenotypic and molecular genetic characteristics. Virtual karyotyping showed gain of chromosomes 3, 4, 10, 13, 17 and 18 in one JGCT, and fluorescence in situ hybridization (FISH) study confirmed this multiple gain pattern. Additionally, loss of chromosome 9 was observed in four of six cases analyzed with FISH. A whole genome expression analysis revealed 415 up-regulated (including renin, and CD117) and 325 down-regulated genes between the 2 cases. The study confirmed earlier reports on the gain of chromosomes 4 and 10, and provided further evidence of up-regulation of the genes located on these 2 chromosomes. For the first time our study indicated the importance of the loss of chromosome 9 and loss of expression of several tumor suppressor genes located on this chromosome as possible pathogenetic events important in development of JGCT.

Hypertension secondary to reninoma treated with laparoscopic nephron-sparing surgery in a child

Reninoma is an extremely rare, renin-secreting, benign kidney tumor that can cause hypertension. We present a case of hypertension secondary to reninoma treated with laparoscopic nephron-sparing surgery in a 15-year-old girl and review some relevant published literature. Laparoscopic retroperitoneal nephron-sparing surgery was performed and the tumor was removed intact. The histopathologic examination showed the characteristic of reninoma with positive CD34 staining immunohistochemically. The patient's blood pressure and level of serum potassium remained normal at 1-month follow-up examination.

Review of juxtaglomerular cell tumor with focus on pathobiological aspect

Juxtaglomerular cell tumor (JGCT) generally affects adolescents and young adults. The patients experience symptoms related to hypertension and hypokalemia due to renin-secretion by the tumor. Grossly, the tumor is well circumscribed with fibrous capsule and the cut surface shows yellow or gray-tan color with frequent hemorrhage. Histologically, the tumor is composed of monotonous polygonal cells with entrapped normal tubules. Immunohistochemically, tumor cells exhibit a positive reactivity for renin, vimentin and CD34. Ultrastructurally, neoplastic cells contain rhomboid-shaped renin protogranules. Genetically, losses of chromosomes 9 and 11 were frequently observed. Clinically, the majority of tumors showed a benign course, but rare tumors with vascular invasion or metastasis were reported. JGCT is a curable cause of hypertensive disease if it is discovered early and surgically removed, but may cause a fatal outcome usually by a cerebrovascular attack or may cause fetal demise in pregnancy. Additionally, pathologists and urologists need to recognize that this neoplasm in most cases pursues a benign course, but aggressive forms may develop in some cases.

Juxtaglomerular cell tumor, causing fetal demise

AIMS

This case report describes juxtaglomerular cell tumor-a rare renin-producing tumor of the kidney, complicating pregnancy.

CLINICAL CASE

A previously healthy 24-year-old primigravid woman developed hypertension in the 20th week of pregnancy, leading to a miscarriage in the 28th week. However, hypertension continued after the miscarriage. A more complete examination revealed a solid tumor in the lower pole of the right kidney. The patient underwent a partial right nephrectomy. A histological examination and electron microscopy confirmed the diagnosis of JGCT. The patient's blood pressure was normalized within 2 weeks.

CONCLUSIONS

JGCT can lead to miscarriage if undiscovered during pregnancy. A kidney ultrasound should be performed on pregnant women with newly detected hypertension. No staining in early phase of contrast CT is the feature that differentiates JGCT from renal cell carcinoma. These tumors are benign, with only one reported exception, and nephron-sparing surgery is preferable.

Secondary hypertension due to a renin-secreting juxtaglomerular cell tumor

A juxtaglomerular cell tumor (JCT) is a rare, renin-secreting tumor of the kidney and can cause hypertension. JCT is pathologically benign, and resection of the tumor is curative for hypertension. We report the case of a 17-year-old girl who had hypertension and hypokalemia for 1 year. Laboratory studies showed increased basal plasma renin activity, but normal serum aldosterone level. Abdominal computed tomography disclosed a 2 cm solid mass in the left kidney. However, renal vein sampling and captopril test results were equivocal. Partial nephrectomy was performed and histologic examination demonstrated typical features of JCT. Hypertension and hypokalemia completely resolved postoperatively. JCT should be considered when investigating hypertensive individuals with high plasma renin activity.

Loss of chromosomes 9 and 11 may be recurrent chromosome imbalances in juxtaglomerular cell tumors

Juxtaglomerular cell tumor (JGCT), first described in 1967, is a rare tumor of the kidney that derived from specialized smooth muscle cells of the wall of the glomerular afferent arteriole. Less than 100 cases have been published, mainly as isolated case reports or small series. JGCTs are considered benign, but the clinical follow-up is short in most reported cases. Only 1 metastatic case has been reported to date, raising the question of tumors of uncertain malignant potential rather than clearly benign neoplasms. Genomic features have been studied in only 2 cases that showed gain of chromosome 10 as well as loss of chromosomes 9, 11q, and X. The present work studied the genomic characteristics of 2 additional cases of JGCT by comparative genomic hybridization. Similarly to the 2 previously reported cases, these 2 tumors showed loss of chromosomes 9 and 11, suggesting recurrent chromosomal imbalances. In addition, 1 case showed gain and loss of entire chromosomes, similar to a previous case studied by karyotyping. Such an aneuploid karyotype may reflect a potential for malignancy as previously reported. Thus, JGCT might be better considered as a tumor of uncertain malignant potential and then necessitates a prolonged follow-up. Future clinicopathologic and genomic studies of large retrospective and prospective series may help to better understand the biology of this fascinating entity.

Juxtaglomerular cell tumor in an 8-year-old girl

Juxtaglomerular cell tumor (JGCT) is an extremely rare renal neoplasm in the pediatric population. It is considered a benign tumor arising from the juxtaglomerular apparatus of the kidney. JGCT has characteristic clinicopathologic features, but its cytogenetic features are unknown. We report a case of JGCT in an 8-year-old female who presented with severe hypertension, elevated serum renin level, and a well circumscribed tumor in the right kidney. Protogranules of renin was identified in the cytoplasm of the tumor cells by electron microscopic examination. Fluorescence in situ hybridization revealed monosomy of chromosomes X, 6, 9, 11, 15, and 21.