Primitive neuroectodermal tumor of the kidney: a single institute series of 16 patients

Practical Management of Adult Ultra-Rare Primary Retroperitoneal Soft Tissue Sarcoma: A Focus on Perivascular Epithelioid Tumours and Extraosseous Ewing Sarcoma

With the exception of well-differentiated liposarcoma, dedifferentiated liposarcoma, leiomyosarcoma, solitary fibrous tumour, malignant peripheral nerve sheath tumour, and undifferentiated pleomorphic sarcoma, the majority of the ≈70 histologic subtypes of retroperitoneal sarcoma are defined as 'ultra-rare' sarcomas, with an incidence of ≤1-5/1,000,000 persons/year. For most of these ultra-rare RPS subtypes, diagnosis and treatment follows international guidelines for the management of more common RPS histologies, with en bloc surgical resection as the mainstay of curative treatment, and enrolment in clinical trials where possible. Because the treatment of RPS is heavily driven by histology, the surgeon must be familiar with specific issues related to the diagnosis and management of ultra-rare sarcoma subtypes. Expert radiological and surgeon reviews are required to differentiate similarly presenting tumours where surgery can be avoided (e.g., angiomyolipoma), or where upfront systemic therapy is indicated (e.g., extraosseous Ewing's sarcoma). Thus, the management of all retroperitoneal sarcomas should occur at a sarcoma referral centre, with a multidisciplinary team of experts dedicated to the surgical and medical management of these rare tumours. In this focused review, we highlight how diagnosis and management of the ultra-rare primary RPS histologies of malignant perivascular epithelioid cell tumour (PEComa), extraosseous Ewing sarcoma (EES), extraosseous osteosarcoma (EOS), and rhabdomyosarcoma (RMS) critically diverge from the management of more common RPS subtypes.

A Large Contemporary Experience of Renal Tumors in Young: Clinico-pathological Profile and Long-Term Survival Patterns

Renal tumors in young population are relatively rare. We reviewed our experience with renal masses in patients below 45 years of age. Our objective was to analyze clinico-pathological and survival characteristics of renal malignancy in young adults in contemporary era. The medical records of patients below 45 years of age who underwent surgery for renal mass at our tertiary care center between 2009 and 2019 were retrospectively analyzed. Pertinent clinical information was compiled, including age, gender, year and type of surgery, histopathology and survival data. A total of 194 patients who underwent nephrectomy for suspicious renal masses were included. Mean age was 35.5 (14-45) years and males were 125 (64.4%). A total of 29/198 (14.6%) specimens had benign disease. In addition, 155 (91.7%) out of 169 malignant tumors were renal cell carcinomas, clear cell variant being the most common type (51%). Compared to RCC, non-RCC tumors were more common in females (27.7 vs 78.6%, p < 0.0001), had an early age of diagnosis (27.2 vs 36.9 year, p < 0.00001) and poorer progression-free (58.3 vs 72.0%, p = 0.03) and overall survival (63.6 vs 84.2%, p = 0.02) at 6 years of follow-up. Renal masses in young adults are most commonly RCC but can also include other diverse types. RCC in young adults is usually organ confined and has good prognosis. As compared to RCC, non-RCC malignant tumors occur in young age, are more in females, and have worse prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13193-022-01643-2.

Renal primitive neuroectodermal tumor: A rare case with a good prognosis

Background

Renal primitive neuroectodermal tumor (rPNET) has the characteristics of a difficult preoperative diagnosis, a high degree of malignancy, easy early metastasis or postoperative recurrence, a poor prognosis, and so on. However, rPNET that has no metastasis before surgery can have a good survival prognosis only after radical surgical resection.

Methods

We report the case of a 14-year-old male patient with a renal tumor who underwent open radical left nephrectomy without radiotherapy or chemotherapy before or after surgery, as confirmed by postoperative pathological results. The prognosis was followed up by a regular review of the chest and whole abdomen on CT, hematuria analysis, renal function, and electrolytes according to the guidelines for renal cancer.

Results

Postoperative pathological results confirmed rPNET; no adjuvant radiotherapy or chemotherapy were performed after surgery; no tumor recurrence or metastasis were observed during the follow-up of nearly 5 years.

Conclusions

Despite the high degree of rPNET malignancy, patients without metastases before surgery can still obtain a good survival prognosis through timely radical surgery.

Extraosseous Ewing's sarcoma/peripheral primitive neuroectodermal tumour of the kidney: a case report and literature review

BACKGROUND

Extraosseous Ewing's sarcoma/peripheral primitive neuroectodermal tumours(EWS/pPNETs) of the kidney are rare. Signs and symptoms are atypical in EWS patients. Presenting symptoms include haematuria, abdominal pain, or a palpable mass. A comprehensive review of the literature shows that it is difficult to make an accurate diagnosis based on physical examination alone. The imaging findings of EWS/pPNETs are nonspecific. We used contrast-enhanced ultrasound (CEUS) to diagnose an EWS/pPNET in our patient, which had never been reported previously to our knowledge.

CASE PRESENTATION

This article reports the case of a 20-year-old female with an abdominal mass and gross haematuria for 1 month. The ultrasound revealed a hypoechoic mass with a clear margin at the lower pole in the left kidney. CEUS demonstrated signs of annular enhancement and heterogeneous enhancement of the tumour, and simultaneous wash-in was predominant. Computed tomography images showed an elliptical low-density tumour. The patient underwent a left kidney resection, and the pathological diagnosis was an EWS/pPNET. Twenty-one days after the kidney operation, the patient underwent 8 cycles of a CAV (vinorelbine, ifosfamide, epirubicin) + IE (isocyclophosphamide, etoposide) chemotherapy regimen. Subsequently, radiotherapy (dose: 45 Gy, radiation field:the tumour bed following surgical resection) was administered for nearly 30 days. The patient had no signs of local recurrence or metastasis within a follow-up of 4 years.

CONCLUSIONS

As a radiation-free, inexpensive, convenient, and repeatable examination method, ultrasound was the primary choice for kidney examination. Early CEUS was helpful to make an accurate diagnosis. Surgery and adjuvant radiation or chemotherapy administered in a timely manner can prevent further deterioration.

Primary primitive neuroectodermal tumour of the kidney in adults: Experience of managing 12 cases with systematic review and pooled analysis of literature

INTRODUCTION

Primitive neuroectodermal tumor (PNET) of the kidney is unusual in adults. These tumours are diagnosed mainly on histopathology and that too sometimes has limitations. With this study, we aimed to review our clinical and histopathological data of patients with renal PNET and reviewing the world literature.

METHODS

In this retrospective study, we reviewed our database from January 2006 to July 2018 to include all the cases of primary PNET of the kidney. We also performed systematic literature search to identify all the relevant series on renal PNET.

RESULTS

A total of 12 patients including 5 men and 7 women were managed during the above mentioned period. Out of these 7 patients, 2 patients had metastasis at diagnosis, one had locally advanced disease, 6 underwent radical nephrectomy, 5 patients received adjuvant chemotherapy (two currently receiving) and only 1 patient received adjuvant radiotherapy (RT). On Immunohistochemistry (IHC), CD99 and FLI1 were positive in all the patients. Median survival was 10 months. In our review 10 studies were included, 38.6% of the patients had metastatic disease and 10.7% had locally advanced disease at diagnosis. Overall mean survival was 33.75 months. CD99 and FLI1 were positive in 94.3% and 78.5%, respectively.

CONCLUSION

PNET remains a pathological diagnosis and IHC has important place in diagnosis of PNET. Locally advanced and metastatic disease is common at diagnosis leading to overall poor survival.

Adolescent-adult nonmetastatic Ewing sarcoma-Experience from a large developing country

BACKGROUND

Outcome and toxicity data in adolescent-adult Ewing sarcoma (AA-ES) patients are sparse and merits exploration.

METHODS

Histopathologically confirmed, nonmetastatic AA-ES patients, who received standard institutional combination chemotherapy regimen (Ewing's family of tumors-2001 [EFT-2001]) comprising of ifosfamide plus etoposide and vincristine, doxorubicin plus cyclophosphamide, lasting a total of 12 months between 2013 and 2018, were analyzed for treatment-related toxicities, event-free survival (EFS), and overall survival (OS).

RESULTS

There were 235 patients (primary safety cohort [PSC]) with median age of 23 (15-61) years; 159 (67.7%) were males, 155 (65.9%) had skeletal primary and 114 (48.5%) had extremity tumors. One hundred ninety-six (83.4%) were treatment naïve (primary efficacy cohort [PEC]) and of these 119 (60.7%) had surgery. In PEC, at a median follow-up of 36.4 (interquartile range [IQR] 20-55) months, estimated 3-year EFS and OS were 67.3% (95% CI 60.3-75.1%) and 91.1% (95% CI 86.7-95.7%), respectively. Of these, 158 (80.6%) complying with intended treatment, at a median follow-up of 39 (IQR 26-57) months had an estimated 3-year EFS of 68.2% (95% CI 60.3-76.1%). In multivariable analysis, good prognostic factors included longer symptom(s) duration (HR 0.93, 95% CI 0.86-0.994), ≥99% necrosis (HR 0.30, 95% CI 0.11-0.77), and treatment completion (HR 0.32, 95% CI 0.14-0.74). Among PSC, grade 3-4 toxicities were febrile neutropenia (119, 50.6%), anemia (130, 55.3%), peripheral neuropathy (37, 15.7%), with three (1.3%) chemo-toxic deaths.

CONCLUSIONS

The outcomes of AA nonmetastatic ES patients treated with EFT-2001 regimen were comparable to those reported by others, with acceptable toxicity. This regimen can be considered a standard of care in AA-ES.

Management of Abdominal Ewing's Sarcoma: A Single Institute Experience

Ewing’s sarcoma (ES)/primitive neuroectodermal tumors (PNETs) are a rare group of tumors commonly arising from bones, uncommonly from soft tissues, and rarely from abdomen. The aim of the study was to analyze the outcome (recurrence-free survival[RFS]), patient characteristics, role of FDG-PET (fluorodeoxyglucose positron emission tomography) computerized scan, chemotherapy and radiation, and prognostic factors. We retrospectively studied patients diagnosed with abdominal ES/PNET and treated surgically between June 2005 and November 2019. Ten patients were included in the study, with a median age of 36.5 years (19–46 years). The median follow-up was 25 months (3–178 months). The site of origin was the retroperitoneum, small bowel, and abdominal wall in six, two, and two patients, respectively. 70% of patients were treated with induction chemotherapy. R0 resection was achieved in 90% of patients. With chemotherapy, there was significant reduction in tumor size (p = 0.034) with non-significant reduction in SUV max (p = 0.31). The 1- and 2-year RFS were 88.90% and 76.20%, respectively. Pathological peritoneal metastasis and ability to achieve R0 resection were prognostic factors affecting RFS. These patients must be offered multimodality treatment. Induction chemotherapy significantly reduces the tumor size. Pathological peritoneal metastasis and ability to achieving R0 resection significantly affect survival.

Renal Primitive Neuroectodermal Tumor With Inferior Vena Cava Thrombus: Case Series and Literature Review of a Rare but Challenging Entity

OBJECTIVE

To investigate the clinicopathological characteristics, treatments, and prognosis of patients with renal primitive neuroectodermal ectodermal tumors (rPNETs) with inferior vena cava (IVC) tumor thrombus.

PATIENTS AND METHODS

We retrospectively reviewed 6 patients with rPNETs and IVC tumor thrombus between January 2005 and December 2019, and identified 39 published cases through a literature review. The clinicopathological characteristics, treatments, and survival data were analyzed.

RESULTS

The median patient age patients was 26 years, and the male to female ratio was approximately 1:1. The average tumor diameter was 12.5 cm. Seventeen patients (37.8%) showed metastasis at diagnosis. Forty-three cases (95.6%) were managed with surgical resection, and 35 (77.8%) received adjuvant chemotherapy after surgery. Follow-up data were available for 41 patients (median follow-up, 10 months; range, 4.5-13.0). The median overall survival (OS) and median progression-free survival (PFS) were both 30.0 months. Patients who received adjuvant chemotherapy had better PFS than those who underwent surgery only (30.0 months [95% confidence interval [CI], 4.3-55.7] vs 5.0 months [95% CI, 1.0-9.0]; P = .036). In terms of OS, however, the difference between the 2 groups was not significant (30.0 months [95% CI, 8.4-52.6] vs 7.0 months [95% CI, 4.5-9.5]; P = .244).

CONCLUSIONS

rPNET with IVCTT is an extremely rare entity that mostly occurs in young adults. Although multidisciplinary treatment is used, the prognosis of this disease remains unclear. RN with IVC tumor thrombectomy is a challenging procedure requiring vascular management techniques and experience. Adjuvant chemotherapy contributes to improved PFS, but not OS. Thus, early diagnosis and treatment play a key role in improving prognosis.

Primary renal Ewing's sarcoma in an adult: an enigma

Objectives

Extraskeletal Ewing’s sarcoma is a rarity, with a renal primary in an adult, being even rarer. There is no consensus on the optimal imaging modality, as well as best therapeutic option, making them an enigma for clinicians.

Case presentation

We report the case of a 34-year-old lady, a known case of invasive lobular carcinoma of the left breast (ER,PR positive, Her2neu negative), having completed treatment in 2017, wherein, on an ultrasound evaluation for left flank pain, was incidentally found to have a left renal mass. A CT scan corroborated with the ultrasound, with an additional Level 1, left renal vein thrombus. She underwent an open left radical nephrectomy with renal vein thrombectomy. Histopathology of the resected tumor revealed features of Ewing’s sarcoma of the kidney, confirmed by Fluorescent In Situ Hybridisation (FISH) and Immunohistochemistry (IHC).

Conclusion

Primary renal Ewing’s sarcoma in an adult is a rare occurrence, with no characteristic imaging features, and no universally accepted guideline based management protocols. Akin with standard Ewings sarcoma treatment strategies, a margin negative- radical nephrectomy with adjuvant chemotherapy, seems the most apt treatment strategy.

Do Primitive Neuroectodermal Tumors of the Kidney Have a Predilection for Inferior Vena Cava Involvement? A Case Series and Review of the Literature

The primitive neuroectodermal tumor (PNET) of the kidney is an extremely rare neoplasm, the diagnosis of which mainly depends upon histopathology, immunohistochemistry (IHC), and cytogenetics. A handful of cases reported in the literature mention about aggressive features of this neoplasm. The purpose of our study was to review our experience in not only the diagnosis and management of the patients with renal PNET but also to highlight its propensity to involve inferior vena cava (IVC) and also present a rare occurrence of Ewing's sarcoma (ES)/PNET of the renal pelvis. The clinical, operative, and histopathology records of four patients of renal PNET treated between January 2017 and December 2019 were reviewed and data analyzed concerning the available literature. Out of the four patients treated, two had level III and IV IVC thrombus, and one had dense desmoplastic adhesions with the IVC wall. One of the cases had a rare presentation of ES/PNET of the renal pelvis. All patients were managed surgically, while only one patient received adjuvant chemotherapy and following up with remission for the last 2 years and 4 months. On IHC, cluster of differentiation-99 (CD-99) was positive in all patients, and three were positive for Friend leukemia integration-1. PNET of the kidney is primarily an immunohistopathological diagnosis. This neoplasm has an increased propensity for the local invasion of surrounding structures. A multimodality approach with surgery, chemotherapy, and radiotherapy could offer better outcomes, although the prognosis of these tumors remains poor.

Primary Ewing Sarcoma/Primitive Neuroectodermal Tumor of the Kidney: The MD Anderson Cancer Center Experience

Limited information exists on the clinical behavior of the Ewing sarcoma family of tumors (ESFT) of the kidney. We reviewed the records of 30 patients (aged 8-69 years) with ESFT of the kidney seen at our institution between 1990 and 2013. We analyzed the event-free survival (EFS) and overall survival (OS) for associations with patient demographics, disease group, tumor size, tumor thrombus, and treatment. Six patients (20%) had tumors confined to the kidney (Group I), seven (23.3%) had local tumor extension beyond the kidney (Group II), and 17 (56.7%) had distant metastasis at diagnosis (Group III). Twenty-five (83.3%) patients underwent radical (19 upfront, five delayed) or partial (one upfront) nephrectomy, 25 (83.3%) chemotherapy and four (13.3%) radiotherapy. The 4-year EFS and OS were 43% (95% CI, 26-61%) and 63% (95% CI, 46-81%), respectively. EFS and OS were significantly associated with disease group and chemotherapy (p < 0.039). The presence of tumor thrombus in renal vein and/or inferior vena cava was associated with worse EFS (p = 0.053). Patients with disease confined to the kidney treated with nephrectomy and adjuvant chemotherapy have favorable outcomes. Local tumor extension beyond the kidney, tumor thrombus, and distant metastasis are unfavorable factors that warrant intensification or novel approaches of therapy.

Primitive neuroectodermal tumour (PNET) of the renal capsule mimicking solid adrenal tumour

Primitive neuroectodermal tumour (PNET) of renal capsule is a rare entity. We report a case of a 17-year-old girl, who presented with symptoms of epigastric and right hypochondrium pain since 1 year. She was afebrile and physical examination revealed a soft, non-tender, firm, bimanually palpable and ballotable mass along right flank. Ultrasound abdomen showed a large heteroechoic mass in right suprarenal region with indistinct planes with upper pole of right kidney. On CT, a large right suprarenal mass was noted with origin likely from right adrenal gland. Surgery was done and intraoperatively, the large mass in right suprarenal region showed involvement of the upper pole of the right kidney. The right adrenal gland was small in size, compressed and displaced by the lesion. Histopathology revealed the mass to be PNET of kidney. We report the relevant imaging findings of the case with review of literature of this entity.

Primary Ewing Sarcoma/Primitive Neuroectodermal Tumor of Kidney With Inferior Vena Cava Thrombus: Findings on 18F-FDG PET/CT

Primary Ewing sarcoma/primitive neuroectodermal tumor is a group of rare aggressive tumors in adults derived from neuroectoderm, and primary renal involvement is extremely rare. We describe an F-FDG PET/CT findings of a 28-year-old man who presented with left renal mass with inferior vena cava thrombus, which turned out to be primary Ewing sarcoma on histopathology specimen post left nephrectomy.

Primitive neuroectodermal tumor of the kidney: A rare case report

Renal primitive neuroectodermal tumor (PNET) is a rare primary renal neoplasm. Morphologically, it may mimic small blue round-cell tumor. Hence, histopathology in conjunction with immunohistochemistry plays a significant role in correctly diagnosing this malignancy. We report a case of PNET of kidney in a 30-year-old female with an extension to inferior vena cava, who succumbed following an aggressive course of illness.

Ewing Sarcoma With Emphasis on Extra-skeletal Ewing Sarcoma: A Decade's Experience From a Single Centre in India

INTRODUCTION

The diagnosis of Ewing sarcoma family of tumours (ESFT) is challenging, especially in adults and in extra-skeletal or visceral location. Several morphologic mimics with varied treatment options and prognosis confer diagnostic dilemmas. Application of ancillary diagnostic modalities in surgical pathology in clinical routine has enabled accurate diagnosis of ESFT in bone, soft tissues, and viscera.

AIM

The study aims to assess the clinicopathological features including molecular test results of ESFT with emphasis on sex, age, and location, especially extra-skeletal soft tissue and visceral location.

MATERIAL AND METHODS

Data of clinicopathological, molecular tests (wherever performed), diagnosis rendered in 302 ESFT over a decade from our centre were reviewed. Statistical comparison of skeletal and extra-skeletal tumours with reference to age and sex was done using SPSS package. The P value of <.05 was considered significant.

RESULTS

The cohort included 302 ESFTs with 49% skeletal and 51% extra-skeletal tumours. Thigh was most common site among skeletal tumours; chest wall, paraspinal location, and retroperitoneum among soft tissues (39.4%); and kidney, ovary, and cervix among visceral tumours (11.3%). Fluorescence in situ hybridisation for EWSR1 gene rearrangement was positive in 54 patients and reverse-transcriptase polymerase chain reaction in 19 patients. Predominance of male sex, younger age and location in extremities among skeletal tumours and lack of gender predilection, higher age and axial location in extra-skeletal tumours were noted, which were statistically significant. Molecular tests were performed more frequently in extra-skeletal tumours, especially in visceral tumours to establish the diagnosis.

CONCLUSIONS

The study showed statistically significant differences in the age, sex, and location between skeletal and extra-skeletal ESFT. The increased percentage of extra-skeletal tumours especially in viscera was attributed to the increased awareness and availability of ancillary techniques.

Primitive neuroectodermal tumour of the kidney presenting as diplopia secondary to skull metastasis

A 20-year-old man presented to the department of neurology with diplopia, occipital headache and right flank pain for 1-week duration. CT of the brain revealed skull metastasis with heterogeneously enhancing dural-based mass lesion at the occipital region. Positron emission tomography revealed tracer avid soft tissue mass involving the upper pole of the right kidney with loss of fat planes with the inferior surface of the liver. Multidisciplinary team approach was discussed. He underwent palliative nephrectomy with lymph nodal mass excision. Biopsy from the renal mass was suggestive of primitive neuroectodermal tumour. He developed progressive liver metastases in spite of adjuvant chemotherapy denoting very aggressive disease.

Peripheral primitive neuroectodermal tumors: A retrospective analysis of 89 cases and literature review

Peripheral primitive neuroectodermal tumors (pPNETs) are rare, small cell carcinomas with a poor prognosis. The aim of the present study was to describe therapeutic approaches, outcomes and probable prognostic factors. The clinical features, treatments, and outcomes of 89 consecutive patients with pPNET treated at the Peking Union Medical College Hospital from 1999 to 2018 were retrospectively reviewed. A total of 43 males and 46 females were included in the study, with a median age of 25 years (range, 5-73 years). The predominantly affected regions were the abdomen and pelvis, followed by the thoracopulmonary region. The mean primary tumor size was 12.6 cm (range, 1-30 cm). A total of 16 patients (18%) initially presented with metastasis. A total of 46 patients received combined therapy, 35 received mono-therapy, and 8 underwent only biopsy with no further treatment. The period of observation ranged from 1-232 months. The median overall survival (OS) time was 15 months [95% confidence interval (CI), 9-21 months], with 3- and 5-year OS rates of 32 and 25%, respectively. Large tumor size [adjusted hazard ratio (aHR)=3.65; 95% CI, 2.07-6.42; P<0.001), metastasis at initial presentation (aHR=4.34, 95% CI, 2.23-8.42; P<0.001), and combined modality treatment (aHR=0.16, 95% CI, 0.06-0.39; P<0.001) were significantly associated with OS. The prognosis of pPNET is, overall, poor. Large tumor size and metastasis at initial presentation are associated with poorer outcomes. This highly malignant tumor requires an aggressive combination of radical resection, chemotherapy and radiotherapy, when indicated.

Primary renal Ewing's sarcoma in a young male treated completely by surgical excision without chemotherapeutic agents: Case report

•

Primary renal Ewing sarcoma is a rare tumor in adults.

•

Proper surgical resection is the most important treatment step.

•

Further studies needed to establish treatment for this tumor.

Introduction

Primary renal Ewing’s sarcoma is a rare tumor with dismal prognosis. The main treatment modality of treatment is surgical excision with adjuvant or neoadjuvant chemotherapy.

Case presentation

We present a case of primary renal EWS in 27-year-old male. He presented to our center complaining of three days history of severe left flank pain associated with nausea and vomiting. Computerized tomography (CT) revealed a 10 × 7 × 6.5 cm left lower pole renal mass. Left radical nephrectomy was performed and revealed a tumor with uniform round to oval nuclei cells. The cells stained strongly positive for CD 99. The diagnosis was established as primary renal Ewing’s sarcoma. The patient refused the chemotherapy. Fortunately, he was free of the disease on regular clinical and radiological follow-up, the last follow up was 30 months post-nephrectomy.

Conclusion

This case highlights the importance of proper surgical treatment and its role in the managing this type of malignancy especially in localized disease at presentation.

Ewing's sarcoma/primitive neuroectodermal tumor of the kidney: a case report and literature review

Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET) is a malignant bone, and soft-tissue tumor derived from neuroectoderm. It occurs in pediatric adolescents with the histopathological features of invasiveness. Renal involvement is extremely rare, which is limited to case reports and small case series. Most patients showed non-specific symptoms, such as abdominal pain and severe hematuria. The corresponding diagnosis was based on pathological features and immunohistochemical detection. So far, the characteristics of computed tomography (CT) have been rarely described in these cases. We report an 18-year-old man diagnosed with renal ES/PNET, who suffered from a sudden left flank pain associated with gross hematuria. The CT images showed an irregular soft tissue mass with a size of 7.3 cm × 7.0 cm × 9.0 cm. The patient underwent laparoscopic nephrectomy of the left kidney. The final diagnosis of renal ES/PNET was confirmed by immunohistochemical detection and fluorescence in situ hybridization of the nephrectomy specimen. We want to point out that CT scanning is still a useful method for preliminary assessment in preoperative diagnosis.

[Six-year disease-free survival after chemotherapy treatment for metastatic renal peripheral neuroectodermal tumor]

Peripheral neuroectodermal tumors (PNET) of the kidney are extremely rare. They are often diagnosed at a late stage due to their nonspecific clinical presentation. Treatment of patients with metastases is based on palliative chemotherapy. We here report a case of PNET of the kidney with sudden onset of metastases to the lymph nodes and to the skin. The patient showed good clinical and radiological response and experienced progression-free survival at 6 years after polychemotherapy with vincristine, doxorubicin and cyclophosphamide.

Imaging of Unusual Renal Tumors

PURPOSE OF REVIEW

Renal masses are a wide entity and a common finding in clinical practice. Detection of these masses has increased in the last years, yet mortality rates have slightly decreased.

RECENT FINDINGS

According to the World Health Organization classification, there are 8 types, 51 subtypes, and a lot more subsequent subclassifications of renal tumors. Histopathological analysis should always be assessed for final diagnosis of theses tumors. However, imaging can be an important diagnostic guidance. The most common diagnoses of renal tumor are clear cell carcinoma, papillary renal cell carcinoma, angiomyolipoma, and transitional cell carcinoma. Nonetheless, a considerable variety of particular tumors can arise from the kidney, challenging the expertise of radiologists and urologists on this subject. The awareness of these unusual entities is vital for professionals working at a complex medical facility with greater volume of patients. We hereby present uncommon renal tumors and its pathological and radiological features.

Primitive neuroectodermal tumour with synchronous ipsilateral clear cell carcinoma of the kidney

We report the first case of a synchronous ipsilateral primitive neuroectodermal tumour (PNET) and clear cell renal cell carcinoma of the kidney. A 37-year-old man presented to the emergency department with a 24-hour history of colicky abdominal pain and visible haematuria. He had no relevant surgical or medical history. Physical examination was unremarkable apart from mild left flank tenderness. Triphasic CT of the abdomen and pelvis showed two solid lesions in the left kidney. Further staging CT of the chest showed no evidence of local or distal metastasis. He subsequently underwent laparoscopic radical nephrectomy. Pathological analysis of the kidney showed two synchronous renal tumours, a clear cell carcinoma and PNET of the kidney. The patient received adjuvant chemotherapy according to Ewing's sarcoma chemotherapy protocol. Surveillance CT scans at 3, 6 and 12 months showed no evidence of disease recurrence or metastasis.

Qualitative and quantitative CECT features for differentiating renal primitive neuroectodermal tumor from the renal cell carcinoma and its subtypes

OBJECTIVE:

To identify important qualitative and quantitative clinical and imaging features that could potentially differentiate renal primitiveneuroectodermal tumor (PNET) from various subtypes of renalcell carcinoma (RCC).

METHODS:

We retrospectively reviewed 164 patients, 143 with pathologically proven RCC and 21 with pathologically proven renal PNET. Univariate analysis of each parameter was performed. In order to differentiate renal PNET from RCC subtypes and overall RCC as a group, we generated ROC curves and determined cutoff values for mean attenuation of the lesion, mass to aorta attenuation ratio and mass to renal parenchyma attenuation ratio in the nephrographic phase.

RESULTS:

Univariate analysis revealed 11 significant parameters for differentiating renal PNET from clear cell RCC (age, p = <0.001; size, p =< 0.001; endophytic growth pattern, p < 0.001;margin of lesion, p =< 0.001; septa within the lesion, p =< 0.001; renal vein invasion, p =< 0.001; inferior vena cava involvement, p = 0.014; enhancement of lesion less than the renal parenchyma, p = 0.008; attenuation of the lesion, p = 0.002; mass to aorta attenuation ratio, p =< 0.001; and mass to renal parenchyma attenuation ratio, p =< 0.001). Univariate analysis also revealed seven significant parameters for differentiating renal PNET from papillary RCC. For differentiating renal PNET from overall RCCs as a group, when 77.3 Hounsfield unit was used as cutoff value in nephrographic phase, the sensitivity and specificity were 71.83 and 76.92 % respectively. For differentiating renal PNET from overall RCCs as a group, when 0.57 was used as cutoff for mass to aorta enhancement ratio in nephrographic phase, the sensitivity and specificity were 80.28 and 84.62 % respectively.

CONCLUSION:

Specific qualitative and quantitative features can potentially differentiate renal PNET from various subtypes of RCC.

ADVANCES IN KNOWLEDGE:

The study underscores the utility of combined demographic and CT findings to potentially differentiate renal PNET from the much commoner renal neoplasm, i.e. RCC. It has management implications as if RCC is suspected, surgeons proceed with resection without need for confirmatory biopsy. On the contrary, a suspected renal PNET should proceed with biopsy followed by chemoradiotherapy, thus obviating the unnecessary morbidity and mortality.

Primitive neuroectodermal tumor of the kidney at the advanced stage: A case series of eight Chinese patients

Primitive neuroectodermal tumor (PNET) rarely occurs as a primary renal neoplasm. Renal (r)PNET is a rare but aggressive neoplasm with poor prognosis; the majority of patients are diagnosed as advanced stage at presentation and face a worse prognosis than patients with localized disease. The present study describes the diagnosis and management of eight cases of rPNET at an advanced stage, who were treated at two institutions [Lingnan Hospital (branch of The Third Affiliated Hospital) and the Cancer Center of Sun Yat-sen University, Guangzhou], from December 2004 to January 2013. The clinical and pathological results of all patients were retrospectively obtained. Kaplan-Meier analysis was performed to estimate patient survival. The study cohort comprised five males and three females. Radical nephrectomy was performed in seven cases, while the remaining case only received needle biopsy of the tumor. Five cases received adjuvant chemotherapy, while three received no further treatment after surgery. Of note, one case received cytokine-induced killer (CIK) cell immunotherapy combined with surgery and chemotherapy. The overall median survival was 20 months with a 3-year survival rate of 25%. The overall survival of the four patients who received adjuvant chemotherapy following surgery was 36 months, compared with 10 months in the three patients without further treatment. The patient who received CIK cell immunotherapy survived for 20 months. Based on the observations of the present and previous studies, surgical excision and chemotherapy are recommended for treating rPNET at advanced stage. Furthermore, the present study was the first to report on CIK cell immunotherapy for a patient with rPNET, indicating that it may be a promising optional treatment. However, further studies are required to validate the benefit of CIK cells and to establish an appropriate immunotherapy protocol.

Renal Tumors of Childhood: Radiologic-Pathologic Correlation Part 2. The 2nd Decade: From the Radiologic Pathology Archives

Malignant renal tumors account for 7% of childhood cancers, and Wilms tumors are by far the most common-but not in older children and adolescents. Among individuals in the latter half of their 2nd decade of life, renal cell carcinoma (RCC) is more common than Wilms tumor. The histopathologic spectrum of RCCs in children differs from that in adults. The most common subtype of RCC in children and adolescents is Xp11.2 translocation RCC, which is distinguished by hyperattenuation at nonenhanced computed tomography, a defined capsule, and associated retroperitoneal lymphadenopathy. Papillary RCC is the second most common histologic subtype. It enhances less intensely compared with the adjacent renal parenchyma and has a propensity for calcification. Clear cell RCC is seen in patients with von Hippel-Lindau disease and is distinguished by its relatively hypervascular nature. Medullary carcinoma affects adolescents with the sickle cell trait and is characterized by an infiltrative growth pattern and extensive metastasis at presentation. Angiomyolipoma is seen in children with tuberous sclerosis complex and is often multifocal and hypervascular, with macroscopic fat. Metanephric tumors are central, circumscribed, and typically calcified. Lymphoma usually manifests as multifocal masses, but it may involve a solitary mass or infiltrative pattern. Extensive adenopathy and involvement of the gastrointestinal tract or other organs also may be seen. Primitive neuroectodermal tumor is an aggressive neoplasm that is typically quite large at diagnosis. Knowledge of the clinical, biologic, and histopathologic features of renal tumors in older children and adolescents and their effects on the imaging appearance can help the radiologist offer a useful preoperative differential diagnosis.

Primitive Neuroectodermal Tumor and Wegener's Granulomatosis of the Kidney: A Curious Combination of Two Rare Entities

Wegener's granulomatosis (WG) is characterized by necrotizing polyangiitis involving the respiratory tract and kidneys. It causes segmental necrotizing glomerulonephritis in the kidneys. In rare cases, a renal pseudotumor may be seen because of the granulomatous process. Association of WG with renal malignancy, however, is very uncommon. We report a case of a patient who presented several years after being treated for WG with malignant hypertension and an infiltrating mass in the right kidney. The histopathology of radical nephrectomy specimen showed presence of primitive neuroectodermal tumor (PNET). Association of renal cell carcinoma (RCC) with WG has been documented in a few cases, but PNET in such circumstances has not been reported. Long-term immunosuppressive treatment is a known risk factor in the development of malignancies, so it is proposed that the occurrence of RCC in WG may have been a side effect of cyclophosphamide treatment. It is not clear whether the same mechanism for PNET holds true in the present case. It is important to make a differential diagnosis between true malignancy and pseudotumors in WG as these entities cannot be distinguished based solely on imaging. We suggest a need to routinely screen the WG patients for increased risk of urologic malignancies.

Outcomes of Adults With Ewing Sarcoma Family of Tumors (ESFT) of the Kidney: A Single-Institution Experience

BACKGROUND

Ewing sarcoma family of tumors (ESFT) of the kidney are exceedingly rare. Given the rarity of this neoplasm and the complexity associated with its management, information regarding treatment and outcome is warranted.

MATERIALS AND METHODS

We conducted a retrospective study of patients with ESFT of the kidney who were treated at MDACC between January 1, 2001 and January 1, 2011. Descriptive statistics were used.

RESULTS

Thirteen patients were identified (median age, 33 y; male:female 11:2). Common presenting symptoms were back pain, flank pain, and hematuria. Six patients had metastatic disease at presentation. Initial diagnostic biopsy was performed in 6 patients. Immunohistochemistry showed strong positivity for CD99 (mic2) and cytogenetic analysis demonstrated evidence of EWSR1 fusion gene in 8 cases. Nine patients underwent nephrectomy. Frequently used chemotherapy regimens consisted of vincristine, doxorubicin, and ifosfamide. Median overall survival was 17.2 months. Three patients were alive at the time of analysis, at 2, 7, and 11 years from diagnosis (the latter without evidence of disease).

CONCLUSIONS

Renal ESFT carry a guarded prognosis with limited response to therapy and short median overall survival. For patients with metastatic disease, diagnostic biopsy and sarcoma-based chemotherapy regimens are recommended as upfront therapeutic strategy. The role of nephrectomy in the metastatic setting is unclear. Future studies with novel therapies are needed.

Neuroendocrine neoplasms of the genitourinary tract in adults: cross-sectional imaging spectrum

Neuroendocrine (NE) neoplasms of the genitourinary (GU) tract in adults are rare tumors with distinct histopathology and variable biological behavior and imaging findings. They may be primary or metastatic in origin. The spectrum of primary GU tract NE neoplasms includes carcinoid, small cell carcinoma, large cell NE carcinoma, and paraganglioma. The tumors commonly show positivity to specific immunohistochemical markers and characteristic dense-core granules at the ultra-structural level. Although imaging findings are nonspecific and accurate differentiation from the more common malignancies of the individual organs is not possible, cross-sectional imaging modalities play an important role in the diagnosis, staging, and surveillance of these tumors. Somatostatin receptor scintigraphy (octreotide scan) may be useful in the detection and treatment of metastatic disease in select patients. Knowledge of the various NE tumors of the adult GU tract and familiarity with their pathological and imaging findings permit optimal patient management.

Primary Ewing sarcoma of the kidney: a case report and treatment review

Ewing sarcomas/primitive neuroectodermal tumors (ES/PNET) of the kidney are rarely found high-grade malignant tumors, offering poor prognosis. Although established treatment guidelines for ES of kidney are scarce, a multi-modality treatment approached is typically implemented. Herein, we report a 14-year-old female patient with ES of right kidney. Post-nephrectomy disease recurrence was treated with chemotherapy (i.e., vincristine, doxorubicin and cyclophosphamide); marked reduction in tumor size (i.e., from 18.5 × 11.3 cm² to 3.7 × 2.2 cm²; ~96% reduction in size) as per computed tomography images was observed. We present our treatment experience and review from the available literature.

Primary Ewing Sarcoma / Primitive Neuroectodermal Tumor of the Kidney: A Clinicopathologic Study of 23 Cases

Primary Ewing sarcoma / primitive neuroectodermal tumor (ES) of the kidney is a rare neoplasm with limited clinicopathologic data. We report 23 such cases with no history of ES elsewhere in the body. The patients included 13 male and 10 female, aged 8-70 years (mean, 31 years). The average tumor size was 11.7 cm (range, 5-20 cm). Microscopic analysis showed predominantly lobular growth (n = 14), with focal papillary (n = 3), alveolar (n = 1), and hemangiopericytoma-like (n = 1) patterns. Several tumors (n = 11) exhibited robust mitotic activity (>10 mitoses/10 high-power fields). Necrosis (n = 13) and lymphovascular invasion (n = 14) were common. Homer Wright rosettes (n = 6) and perivascular pseudorosettes (n = 1) were also identified. The tumors invaded the renal sinus or perinephric fat (n = 11), renal vein (n = 13), and adrenal gland (n = 2). Molecular and fluorescence in situ hybridization analysis showed rearrangement of EWSR1 gene (10/10), associated with EWSR1-FLI1 gene fusion (7/10). All patients with follow-up information (n = 18) had metastasis, commonly in the lungs (n = 12) and bone (n = 6). Twelve patients died of disease in a mean of 21 months; 6 patients were alive at a mean of 49 months after diagnosis. Primary kidney ES usually present at an advanced stage with extrarenal spread and metastasis. Although renal ES share histologic, immunohistochemical, and molecular features with their bone and soft tissue counterparts, they appear to be more aggressive tumors with poorer clinical outcome.

Ewing Sarcoma/Primitive Neuroectodermal Tumor of the Kidney: A Rare and Lethal Entity

Ewing sarcoma/primitive neuroectodermal tumor represents a spectrum of undifferentiated tumors with similar biology that together represent the second most common sarcoma in the pediatric-young adult age range. Very rarely, this tumor presents as a primary neoplasm of the kidney. The clinical presentation of this tumor is not specific, and other renal tumors may present with a similar histologic appearance. Establishing the correct diagnosis is critical because renal Ewing sarcoma/primitive neuroectodermal tumor carries a strikingly dismal prognosis and thus dictates a specific treatment strategy. A low threshold for the use of ancillary molecular tests is recommended, particularly in diagnostically problematic cases. Important considerations with regards to morphology, immunohistochemistry, and molecular alterations will be reviewed here and should be taken into account before rendering this rare and lethal diagnosis.

Primary renal primitive neuroectodermal tumor

Primitive Neuroectodermal Tumor of the kidney is a rare entity. Very few cases of primary renal PNET have been reported to date. Most literature about rPNET is isolated case reports. We report a case of rPNET in a 39-year-old male with a pre-operative diagnosis of renal cell carcinoma with renal vein thrombosis. The patient underwent radical nephrectomy with thrombolectomy, and histopathological examination revealed a highly aggressive tumor composed of monotonous sheets of round cells. Tumor cells were positive for CD 99 and FLI-1, hence confirming the diagnosis of Primitive Neuroectodermal Tumor. Post-surgery, patient was given VAC/IE-based adjuvant chemotherapy. In view of highly aggressive nature of this tumor, prompt diagnosis and imparting effective chemotherapy regimen to the patient is required, and it is important to differentiate PNET from other small round-cell tumors because of different therapeutic approach.

[Primitive neuroendocrine/ectodermal kidney tumor]

PNET of the kidney are rare, aggressive tumors that occur mainly in adolescents. The diagnosis of PNET is difficult, but is possible with pathognomonic radiological findings. Since a radical nephrectomy is generally not sufficient for PNET of the kidney, early diagnosis and treatment is essential for successful recovery.

Management of Primitive Neuroectodermal Tumor of the Kidney with Inferior Vena Cava Thrombus

Primitive neuroectodermal tumors (PNET) are an aggressive group of small round cell tumors usually arising in the nervous system and affecting children. They have a tendency for local invasion, distant spread and formation of tumor thrombi. The kidney is a rare primary location for these tumors. Outcomes are frequently poor due to late diagnosis (Wilms tumor is a more common tumor in this population) and early spread. Immunohistochemistry is invaluable in making the diagnosis of PNET. We report a case of a primary renal PNET with extensive tumor thrombus into the inferior vena cava, and lung metastasis in a pediatric patient, and its successful management. Our 14-year-old patient with renal PNET was managed with radical nephrectomy, thrombectomy and chemotherapy and remains disease free to date. The diagnosis of renal PNETs should be considered in young adult patients who present with aggressive renal masses at initial presentations. Despite its aggressive nature, good outcomes can be achieved by a multimodality therapeutic strategy.

Rare Renal Incidentaloma in Pregnancy: An Unusual Primitive Neuroectodermal Tumor Presentation

Peripheral Primitive Neuroectodermal Tumors (PNETs) are rare lesions that arise from outside the central nervous system and normally do not affect the genitourinary system. Primary renal presentations are extremely rare but given their aggressive behavior and characteristic cytomorphologic and genetic features should be considered well-defined distinct clinical entities in order to distinguish them from other primary tumors featuring round cells in the kidney. We report one case of PNET involving the kidney and associated with pregnancy.

Renal Primitive Neuroectodermal Tumor: A Case Report

Primitive neuroectodermal tumor (PNET) is a malignant small round cell tumor and typically arises from bone or soft tissue in adolescents and young adults. Renal PNET is extraordinarily rare and exhibits highly aggressive biological behavior with poor prognosis.We present here a new case of renal PNET in a 31-year-old female. The patients were referred to our hospital because of left flank pain with nausea and vomiting for 1 week. A computed tomography scan revealed a 14.7 × 12.7 cm well-defined, unevenly mass lesion with both solid and cystic components and the tumor was not enhanced uniformly.A preoperative diagnosis of cystic renal cell carcinoma and urinary tract infection was made. The patient undergone anti-inflammatory therapy followed by a left radical nephrectomy. Taken with morphological pattern and immunohistochemical markers, a diagnosis of renal PNET was made. Two cycles of combined chemotherapy were executed. At the 14-month follow-up, no evidence of metastasis or recurrence was indicated.This case reminds clinicians that for adolescents and young adults with a suspicious renal mass, a diagnosis of renal PNET should be always considered. An initial surgery followed by radiotherapy and chemotherapy is suggested for the therapeutic management.

A large and metastatic primitive neuroectodermal tumor of the kidney

Primitive neuroectodermal tumor (PNET) of the kidney is rare. Mostly patients with renal PNET are young adults and the survival rates are poor. Although radiological and pathological investigations, differential diagnosis from other kidney tumours is very difficult. The treatment is often delayed because of difficulties with diagnosis. In most cases of renal PNET, as in this case, prognosis is poor. Particularly, in young adults with large renal masses, it must be diagnosed and treatment should be started immediately.

Soft tissue sarcomas of the kidney

Soft tissue sarcomas are rare mesenchymal tumors. Amongst others, primitive neuroectodermal tumors (PNET) of the kidney and synovial sarcoma of the kidney belong to the group of soft tissue sarcomas. Synovial sarcomas can occur almost anywhere in the body, most frequently, however, in the lower (62%) or upper extremities (21%). Metastases occur in 50-70% of cases, and thus the prognosis is poor. PNETs are rare, highly aggressive neoplastic lesions which mainly occur in the torso or axial skeleton in young adults. The prognosis is poor with a 5-year disease-free survival rate of 45-55%. The primary therapeutic approach is surgical resection. Most randomized studies assessing adjuvant chemotherapy for all types of localized soft tissue sarcomas did not show statistically significantly better overall survival times after chemotherapy, although they did show longer progression-free survival. We report on two cases of primary renal synovial sarcoma and one case of PNET of the kidney.

Primitive neuroectodermal tumor (PNET) of the lung in an adult woman

Primary primitive neuroectodermal tumors (PNETs) are extremely rare in the lung and especially in adult women. We describe a case of PNET of the lung with aggressive behavior in 31-year-old woman. Diagnosis was based on histopathological and immunohistochemical studies, and confirmed by molecular genetic analysis of chromosome rearrangements in the EWSR1 gene region. Clinical follow-up, post-mortem findings, and differential diagnosis are also discussed.

Peripheral primitive neuroectodermal tumor of the kidney in a 51-year-old female following breast cancer: A case report and review of the literature

Peripheral primitive neuroectodermal tumor/Ewing's sarcoma (pPNET/EWS) is an aggressive type of sarcoma that is rarely observed in the kidney. pPNET of the kidney principally occurs in young patients (<50 years old) and is very rare in older patients (≥50 years old). Additionally, only six cases of pPNET of the kidney have been reported in the literature in older patients (≥50 years old), and pPNET as a secondary primary tumor has rarely been reported. The current study presents a case of renal pPNET in a 51-year-old female who had been surgically treated for breast carcinoma and administered with adjuvant chemotherapy five years prior to hospitalization for pPNET. A computed tomography scan identified a tumor in the lower pole of the right kidney, which was treated by nephrectomy. Immunohistochemistry demonstrated diffuse, strong membranous positivity for cluster of differentiation (CD)99, positive nuclear staining for friend leukemia integration 1, and negative staining for Wilms' tumor 1 and other markers. Fluorescence in situ hybridization (FISH) analysis of the EWS breakpoint region 1 (EWSR1) demonstrated the characteristic EWSR1 translocation. The patient declined chemotherapy or radiotherapy but accepted traditional Chinese medicine. No evidence of recurrence was observed eight months after diagnosis. Only two cases of renal pPNET with a history of an earlier or synchronous primary cancer were reported in the literature from the USA and Germany, respectively. To the best of our knowledge, the present case is the first FISH-confirmed renal pPNET in an older patient following breast adenocarcinoma.

Renal primitive neuroectodermal tumour: Case series and brief review

Renal primitive neuroectodermal tumor is a rare malignancy. These tumours rarely present with caval involvement. We report 2 cases of primitive neuroectodermal tumours (PNETs) with inferior vena cava involvement. The initial presentation and outcomes differed significantly. The diagnosis was confirmed using histologic and pathologic analysis. We present a brief literature review and an outline of typical clinical and pathologic features of renal PNETs.

Renal Ewing tumors

BACKGROUND

Renal Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) is extremely rare. Clinical symptoms are nonspecific presenting abdominal pain, palpable mass, and hematuria. Owing to advanced technology demonstrating the ES-specific EWS/ETS translocation, this differential diagnosis has become feasible.

PATIENTS AND METHODS

The German database of GPOH Ewing's sarcoma trials from 1980 to 2009 was searched for kidney as primary site. Twenty-four patients were identified and analyzed. The median time of observation was 3.71 years (range 0.27-8.75 years). Additionally, we carried out a Medline search for renal ES/PNET.

RESULTS

The median age was 24.9 years (range 11-60 years). In 37.5%, patients presented with primary metastases. Tumor thrombi in the adjacent renal vessels occurred in 56.2%. In 90.9%, rearrangements of t(11;22) were found. All patients received a combined chemotherapy according to the EURO-E.W.I.N.G.99 protocol. In accordance, local control consisted predominantly of combined modality surgery and radiation (47%). At 3 years, overall survival (OS) was 0.80 (SE = 0.09), and event-free survival (EFS) 0.66 (SE = 0.11).

CONCLUSIONS

ES/PNET should be considered in the differential diagnosis of renal tumors. Patients with renal ES/PNET respond to and benefit from conventional ES treatment according to ES study protocols. Therefore, an accurate diagnostic approach and a guideline-adapted therapy should be facilitated.

Primary Ewing sarcoma of the kidney: a symptomatic presentation and review of the literature

The objective of this review is to discuss the unique nature of primary renal Ewing sarcoma, including incidence, presentation and management. We also report on a common pattern of presentation, consisting of acute flank pain mimicking a renal stone colic, with or without hydronephrosis, and a renal mass discovered during imaging studies of renal Ewing sarcoma. We present our case of renal Ewing sarcoma along with imaging and pathological analysis. We also performed a retrospective review of all cases of renal Ewing sarcoma using PubMed. A total of 48 cases of renal EWS sarcoma have been reported and analyzed in this review. A mean age of 30.4 years was found along with a 61% male predominance. The mean survival was 26.14 months with a lower median survival in patients with advanced metastatic disease. Primary Ewing sarcoma of the kidney is rare. The diagnosis of primary renal EWS can be difficult and is based on a combination of electron microscopy, immunohistochemistry, chromosomal analysis, fluorescence in situ hybridization (FISH) and light microscopy.

Thoracic primitive neuroectodermal tumor: an unusual case and literature review

We describe herein a rare case of a primary primitive neuroectodermal tumor (PNET) in the mediastinum of a 75-year-old man. Grossly, the tumor was located in the left upper anterior mediastinum. Transcutaneous fine-needle biopsy (TCNB) revealed small round-cell proliferation. The expression immunohistochemical analysis was confirmed the diagnosis of PNET. He was successfully treated with chemotherapy and is alive with no sign of recurrence for 17 months after the diagnosis.

Renal primitive malignant tumor with endocrine activity

OBJECTIVE

To report a hypertensive and systematically pigmented female with primitive neuroectodermal tumors.

CLINICAL PRESENTATION AND INTERVENTION

A female patient presented with a complaint of right flank pain. She had a right renal space-occupying lesion, underwent right radical nephrectomy, and returned to normotensive postoperatively. The pathological examination identified typical primitive neuroectodermal tumor histology. During a 60-month follow-up period, she remained normotensive and demonstrated normal renal and adrenal functions.

CONCLUSION

Early diagnosis and definitive surgery led to the patient's long-term survival.

Primitive neuroectodermal tumor of the kidney: case report and review of literature

BACKGROUND

Renal primitive neuroectodermal tumor (rPNET) as a member of Ewing's sarcoma family is extremely rare and usually occurs in children and young adults. Most literature about rPNET was isolated case reports.

CASE PRESENTATION

We reported a case of 45-year-old man with the complaint of right flank pain. Computerized tomography (CT) scan demonstrated a large substantive tumor involving the lower pole of the right kidney. Then the patient underwent radical nephrectomy. Pathologic characteristics and immunohistochemical analysis confirmed the diagnosis of rPNET. Additionally, the patient received three cycles of chemotherapy, and was still alive without metastasis at 15-months follow-up.

CONCLUSION

rPNET is rare and presents aggressive clinical behavior and worse prognosis. We expect that further awareness and study of this rare tumor can be had by presenting our case.