Primitive neuroectodermal tumor arising in the abdominopelvic region: CT features and pathology characteristics

Ewing sarcoma of the pancreas: a pediatric case report and narrative literature review

Ewing's Sarcoma (ES) is an rare, small round-cell sarcoma that predominantly occurs in children and young adults, with both skeletal and extraskeletal manifestations. However, pancreatic ES, due to its rarity, is infrequently featured in scholarly literature, with only a scant 43 reported instances. Our study describes a case of pancreatic ES in an 8-year-old boy who was found to have an abdominal mass. Following an exhaustive examination, the boy was diagnosed with a neoplasm in the pancreatic head and underwent a complex surgical procedure encompassing pancreatoduodenectomy and partial transverse colectomy. Immunohistochemical assays confirmed the neoplastic cells' positivity for Cluster of Differentiation 99(CD99), Vimentin, and NK2 Homeobox 2(NKX2.2), while genomic testing identified an EWSR1-FLI1(Ewing Sarcoma Breakpoint Region 1-Friend Leukemia Integration 1) gene fusion. This led to a conclusive diagnosis of pancreatic Ewing's Sarcoma. The patient underwent seven cycles of adjuvant chemotherapy, alternating between VDC (Vincristine, Doxorubicin, Cyclophosphamide) and IE (Ifosfamide, Etoposide) tri-weekly, but did not undergo radiotherapy. At present, the patient remains neoplasm-free. Through our case analysis and comprehensive review of the existing literature, we aim to underscore th rarity of pancreatic Ewing's sarcoma and to highlight the efficacy of our individualized therapeutic approach.

Primitive Neuroectodermal Tumour Invading the Inferior Vena Cava

In the present report, we describe our experience with a 44-year-old male with abnormal retroperitoneal primitive neuroectodermal tumours (PNETs) in our hospital, who was operated on with a spindle cell neoplasm diagnosis.

LEARNING POINTS

Appropriate treatment is a crucial challenge in patients with PNETs due to late referral.The differential diagnoses were malignant pheochromocytoma, paraganglioma and retroperitoneal sarcoma.Physicians should keep in mind that the patient could be simultaneously suffering from sarcoma and a retroperitoneal PNET.

[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.

Primary Intra-abdominal Ewing's Sarcoma in Adults: A Multimodality Imaging Spectrum

Ewing sarcoma (ES) and peripheral primitive neuroectodermal tumor are part of a spectrum of neoplastic diseases known as the ES family of tumors, which also includes extraosseous ES, peripheral primitive neuroectodermal tumor, malignant small-cell tumor of the thoracopulmonary region (Askin's tumor), and atypical ES. Although imaging features of these tumors have been previously described, extensive discussion about intra-abdominal manifestations is scarce in the literature. We present an imaging spectrum of these tumors in the abdomen and pelvis with particular attention to multimodality approach for staging and restaging.

Radiological features of primitive neuroectodermal tumors in intra-abdominal and retroperitoneal regions: A series of 18 cases

Objectives

To characterize the imaging and clinicopathological features of primitive neuroectodermal tumors (PNETs) arising in intra-abdominal and retroperitoneal regions.

Methods

Eighteen patients with histopathologically proven intra-abdominal and retroperitoneal PNET were enrolled; computed tomography was performed for all cases, and magnetic resonance imaging was performed for a single case. Typical computed tomography and magnetic resonance imaging findings, including morphology, texture and enhancement features, as well as clinicopathological characteristics and prognosis data were retrospectively analyzed.

Results

Of eighteen PNET patients, fifteen were male and three were female, with a median age of 36 years (range, 2–65 years). The onset of symptoms was most often nonspecific and insidious. The mean tumor diameter was 7.2 cm (range, 3.0–12.1 cm), with necrosis in fifteen cases, cystic changes in eight, partition structure in five, calcification in five, hemorrhage in two, and mural nodules in one. Contrast enhanced computed tomography showed multiple tiny feeding arteries within the masses in six cases, resulting in a crab-like appearance, and mild ring enhancement pattern in five cases. Eleven cases showed surrounding invasion and metastasis. Of the eighteen PNET cases, nine cases showed smooth, well-defined margins, and nine cases had irregular, ill-defined margins. A median survival was 10.0±1.6 months. However, chemotherapy had efficacy on patients even those with advanced disease.

Conclusions

Primary intra-abdominal and retroperitoneal PNETs are rare, and imaging features documented here may help the diagnosis of this severe disease. Notably, two signs present in retroperitoneal PNET tumors, including a mild ring enhancement pattern and a crab-like appearance of the tiny feeding arteries, may have the potential to help us improve the ability to make a relatively reliable diagnosis.

CT Features and Pathological Correlation of Primitive Neuroectodermal Tumor of the Kidney

The purpose of the study was to analyze the computed tomography (CT) findings of primitive neuroectodermal tumor (PNET) of the kidney and correlate them pathologically. Ten cases of pathologically confirmed renal PNET were collected and retrospectively reviewed. The CT features that were analyzed include tumor size, shape, margins, density, nature of enhancement, presence of thrombosis, and metastasis, etc. These parameters were correlated with pathological findings and combined with literature review. The median age of the patients was 30 years. CT images showed solitary, large, ill-defined, irregular, or lobulated heterogeneous mass. Invasive growth toward the renal cortex and pelvis with renal cortical interruptions were seen in eight cases with one case exhibiting invasion that extended beyond the renal capsule with soft tissue seen in the perirenal fat pace. The tumors were confined to the kidney contour with enlargement of kidney in six of the cases. Cystic changes with mural nodules were detected in three cases. Eight cases showed persistent moderate enhancement during the nephrographic phase. Irregular septum-like structures were seen in four cases. Thrombosis was detected in eight cases. Lymph node metastasis was detected in eight cases with bilateral lung metastasis in two and bone metastasis in one. Renal PNET is a rare highly aggressive disease affecting younger people. It should be considered as a strong differential when well confined, yet large tumors that cause enlargement of the kidney are seen and also when tumors expressing cystic changes along with mural nodules are seen. Although renal PNET has certain other characteristic CT features, pathological and immunohistochemistry report must also be sought for definitive diagnosis.

Imaging findings of adrenal primitive neuroectodermal tumors: a series of seven cases

OBJECTIVE

To explore the imaging features of adrenal primitive neuroectodermal tumors (PNETs).

MATERIALS AND METHODS

This retrospective study included seven patients with surgically and pathologically confirmed adrenal PNETs. Among them, six underwent computed tomography (CT) scans, and one underwent magnetic resonance imaging. The imaging findings, including size, shape, margin, hemorrhage, calcification, cystic degeneration, regional lymph nodes involvement, tumor thrombus formation and enhancement pattern, were retrospectively analyzed.

RESULTS

Among the seven adrenal PNET patients, six were male, and one was female. The median age was 26 years (range 2-56 years). The disease generally presented with either insidious symptoms (n = 4) or non-specific symptoms, including right flank pain (n = 1) and left upper abdominal discomfort (n = 2). On the pre-enhanced CT images, the tumor usually appeared as a well-defined, rounded or oval, heterogeneous mass without calcification. Certain tissue characteristics, such as cystic degeneration (n = 5), capsule (n = 4) and hemorrhage (n = 2), were observed. Regional lymph node involvement was observed in three cases, and renal vein thrombus was observed in one case. All cases showed mild heterogeneous enhancement of the tumor on the enhanced CT images.

CONCLUSION

An adrenal PNET commonly presents as a relatively large, well-defined, heterogeneous mass with cystic degeneration, necrosis and a characteristic mild contrast-enhancement pattern on multiphase enhanced images. PNET should be considered when the diagnosis of common tumors is not favored by signs on images.

CLINICAL TRIAL REGISTRATION STATEMENT

This study was approved by the medical ethics committee of Xiangya Hospital, Central South University. The approval number is 201512538.

CT and clinical findings of peripheral primitive neuroectodermal tumour in children

OBJECTIVE

To describe the clinical, CT and pathological findings of paediatric peripheral primitive neuroectodermal tumours (pPNETs) to enhance the recognition of these rare tumours.

METHODS

The clinical, CT and pathological findings of 18 paediatric patients with pPNETs confirmed by biopsy or surgical pathology were retrospectively reviewed.

RESULTS

The age of these 18 paediatric patients with pPNETs ranged from 4 months to 15 years, with a mean age of 7.7 years. The lesions of these 18 paediatric patients with pPNETs were located in the head and neck (n = 4), chest (n = 2), abdomen and pelvic cavity (n = 6), spine (n = 3), ilium (n = 2) and femur (n = 1). Immunohistochemical examination revealed Homer-Wright rosettes in seven lesions, and 94.4% of lesions showed consistent positive staining for CD99. On plain CT images, the majority of pPNETs showed lesions that were ill-defined (72.2%), irregularly shaped (83.3%), heterogeneous (66.7%) or hypodense masses (94.4%), and together with osteolytic bone destruction when the lesion originated in the bone. Calcifications were found in three lesions. After contrast administration, all soft-tissue masses were persistently enhanced heterogeneously with various cystic or necrotic regions, and 71.4% of them had linear enhancement. 94.4% of soft-tissue masses showed a moderate degree of enhancement. Seven cases had lymph node metastasis at diagnosis.

CONCLUSION

Paediatric pPNET can involve any part of the body, and a large, ill-defined, aggressive soft-tissue mass and moderate heterogeneous enhancement with varying cystic regions and linear enhancement, with or without osteolytic bone destruction, on CT images could suggest the diagnosis.

ADVANCES IN KNOWLEDGE

Primitive neuroectodermal tumours constitute a rare type of malignant neuroectodermal tumours that have chromosomal translocations identical to Ewing's sarcoma, and reports about radiological characteristics of this disease in children are insufficient. This study has described the clinical features and CT and pathological findings in 18 paediatric patients diagnosed with pPNETs in different locations, as a way to enhance the recognition of these tumours and help to differentiate from other types of paediatric malignant bone and soft-tissue tumours.

Peripheral primitive neuroectodermal tumor: dynamic CT, MRI and clinicopathological characteristics--analysis of 36 cases and review of the literature

Background

The peripheral primitive neuroectodermal tumor (pPNET) is a rare malignant tumor originating from neuroectoderm. The accurate diagnosis is essential for the treatment of pPNET.

Methods

we performed the largest cases of retrospective analysis thus far to review the unique computed tomography (CT), magnetic resonance imaging (MRI), and clinicopathological features of pPNET. The tumor location, morphological features, signal intensity, contrast enhancement characteristics, and involvement of local soft tissues of 36 pPNETs were assessed.

Results

Our results showed that there were more men (25/36) than women pPNETs patients. Unenhanced MRI (16 cases) showed that 14 cases were isointense and 2 cases were hypointense on T1WI. Nine cases were isointense and 7 were hyperintense on T2WI. Most pPNETs had heterogeneous signal intensity with small necrosis (CT: 31/36; MRI: 14/16) as well as heterogeneous enhancement (CT: 34/30; MRI: 15/16). The tumors usually had ill-defined borders and irregular shapes (CT: 30/36; MRI: 15/16). Pathologic exam showed small areas of necrosis in all tumors.

Conclusions

The diagnosis of pPNET should be suggested in young men when the imaging depicts a single large ill-defined solid mass with small area of necrosis, especially for those whose images show iso-intense on T1WI and T2WI and have heterogeneous enhancement.

Radiologic and clinicopathologic findings of peripheral primitive neuroectodermal tumors

BACKGROUND

Primitive neuroectodermal tumors (PNETs) constitute a rare type of malignant neuroectodermal tumors that have chromosomal translocations identical to Ewing's sarcoma (ES), and the characteristics of this disease remain unclear.

PURPOSE

To describe the clinical, radiological, and pathological features of peripheral PNETs (pPNETs) to enhance their recognition.

MATERIAL AND METHODS

The clinical, imaging, and pathologic findings of 35 patients with pPNETs were retrospectively reviewed, all being confirmed by biopsy or surgical pathology. All 35 patients had preoperative computed tomography (CT) examinations; 10 patients had preoperative magnetic resonance imaging (MRI) studies.

RESULTS

Of 35 pPNET patients, 54.3% had a primary tumor in soft tissue, the others in bone. On plain CT images, 33 lesions demonstrated heterogeneous hypodense masses with multiple lamellar lower density, and with osteolytic destruction if the tumor originated in bone. Calcification was only found in five lesions arising in soft tissue. All lesions enhanced heterogeneously with varying areas of cystic changes, and all lesions in bone and 52.6% of lesions in soft tissue showed ill-defined margins after contrast administration. On MRI, these tumors appeared in conjunction with osteolytic bone destruction and irregular soft tissue masses iso- to hypointense to skeletal muscle on T1-weighted images and showed heterogeneously high intensity on T2-weighted images. All lesions enhanced heterogeneously with cystic changes. Homer-Wright rosettes were observed in 15 lesions, and 97.1% lesions were positive for CD99 in histopathological results.

CONCLUSION

pPNETs can involve any part of the body, and a large, ill-defined, aggressive soft tissue mass and heterogeneous enhancement with or without osteolytic bone destruction on CT or MR images could suggest the diagnosis.

A to Z of extraskeletal Ewing sarcoma family of tumors in adults: imaging features of primary disease, metastatic patterns, and treatment responses

OBJECTIVE

Though classically thought of as an osseous-based sarcoma of children and adolescents, it is important to recognize that approximately 20% of all cases of Ewing sarcoma family of tumors (ESFT) occur in patients older than 18 years, often with extraskeletal disease. Understanding the specific imaging features, manners of presentation, and patterns of behavior of ESFT is therefore important in all settings.

CONCLUSION

This article presents the imaging findings of ESFT in the adult, with specific attention to extraskeletal manifestations.