Renal primitive neuroectodermal tumors

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.

Renal Ewing's sarcoma/primitive neuroectodermal tumor (PNET): a case series of 7 patients and literature review

Background

Primitive neuroectodermal tumor (PNET) is a rare kind of sarcoma that is primarily found in the kidney and has a very poor prognosis. Here, we review and summarize the clinical data of patients with renal PNET in our center and follow up the patients for survival status. Although the current literature suggests that chemotherapy may benefit the survival of these patients, the information from our center suggests that this may not be the case.

Methods

We retrospectively analyzed the clinical data of patients with renal PNET diagnosed pathologically at Peking University First Hospital from January 1, 2007, to January 1, 2018. All of the patients were followed up for survival status.

Results

Seven patients with renal PNET were found. The ratio of males to females was 6:1. The median age was 29 years (21–72 years) at the time of diagnosis. The preoperative imaging examination showed a large renal mass protruding outwards from the renal contour, with internal necrosis and hemorrhage. Six/7 patients were diagnosed with distant metastasis or retroperitoneal lymph node metastasis. The main clinical manifestations of patients were pain (5/7) and fever (3/7). In immunohistochemistry, all patients’ samples were CD99 positive. All patients died in our follow-up, with an average overall survival (OS) of 12.09 months (1.90–26.77 months).

Conclusions

As a rare renal tumor, renal PNET has a propensity to occur in young males. Most patients have distant metastasis when they are diagnosed, and the prognosis is very poor. Effective treatments are urgently needed.

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.

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.

Primary Renal Ewing Sarcoma in an Adult

Primary renal Ewing sarcoma is extremely rare and carries a dismal prognosis. It is particularly diagnostically challenging due to its ability to mimic other round cell tumors. Herein we report such a case in a 28-year-old white female. The diagnosis was confirmed by immunophenotyping, fluorescence in situ hybridization, and reverse transcription polymerase chain reaction analyses.

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.

Primary primitive neuroectodermal tumor of the cervix

Primary primitive neuroectodermal tumors (PNETs) are rare and high-grade malignant tumors that mostly occur in children and young adults. The most common sites are the trunk, limbs, and retroperitoneum. Herein, we present a case of a PNET involving the cervix uteri in a 27-year-old woman. The lesion showed characteristic histologic features of a PNET and was positive for the immunohistochemical markers cluster of differentiation (CD) 99, vimentin, neuron-specific enolase, neural cell adhesion molecule 1 (CD56), and CD117 (c-kit), further defining the tumor while helping to confirm PNET. The clinical Stage IIIB tumor was treated with chemotherapy and radiotherapy.