Imaging of peripheral PNET: common and uncommon locations

Primary adrenal Ewing sarcoma: A systematic review of the literature

BACKGROUND

Ewing sarcoma (ES) is a malignant neoplasm of neuroectodermal origin and is commonly observed in children and young adults. The musculoskeletal system is the main body system impacted and ES is rarely seen in the visceral organs particularly the adrenal gland.

AIM

To present a comprehensive review of primary adrenal ES, with emphasis on diagnosis, therapy and oncological outcomes.

METHODS

A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020. PubMed/ MEDLINE, EMBASE and Google Scholar bibliographic databases were searched to identify articles from 1989 to 2022 and included patients with ES/primitive neuroectodermal tumor (PNET) of the adrenal gland. PubMed, Google Scholar and EMBASE medical databases were searched, combining the terms "adrenal", "ES" and "PNET". Demographic, clinical, pathological and oncological data of patients were analyzed by SPSS version 29.0.

RESULTS

A total of 52 studies were included for review (47 case reports and 5 case series) with 66 patients reported to have primary adrenal ES. Mean age at diagnosis was 26.4 ± 15.4 years (37.9% males, 57.6% females, sex not reported in 3 cases). The most frequent complaint was abdominal/flank pain or discomfort (46.4%) followed by a palpable mass (25.0%), and the average duration of symptoms was 2.6 ± 3.1 mo. The imaging modality of choice was computed tomography scan (81.5%), followed by magnetic resonance imaging (20.4%). Preoperative staging revealed that 17 tumors (27.9%) were metastatic and 14 patients had inferior vena cava or renal vein neoplastic thrombus at initial diagnosis. Open adrenalectomy was performed in the majority of cases (80.0%), of which 27.9% required more extensive resection. Minimally invasive surgery was attempted in 8.2% of tumors. Complete surgical resection was achieved in 89.4% of the patients. Adjuvant therapy was administered to 32 patients, in the form of chemotherapy (62.5%), radiotherapy (3.1%) or combination (34.4%). Median overall survival was 15 mo and 24-mo overall survival was 40.5%. Median disease-free survival was 10 mo and 24-mo disease-free survival was 33.3%.

CONCLUSION

The significant progress in molecular biology and genetics of ES does not reflect on patient outcomes. ES remains an aggressive tumor with a poor prognosis and high mortality.

Experience of CT diagnosis and management of primary renal Ewing's sarcoma: A retrospective analysis of 6 cases and a literature review

To present the clinical experience of primary renal Ewing's sarcoma/primitive neuroectodermal tumors (rEWs/PNET) admitted to our hospital and systematically review the published literature. A retrospective analysis was performed on patients with pathologically confirmed renal EWs/PNET (rEWs) in our hospital, and the literature on rEWs published in PubMed and Embase databases before March 1, 2022 was searched for analysis. A total of 337 rEWs were included in the statistical analysis, including 6 cases of our patients and 331 cases published in the literature. The common clinical symptoms of rEWs are abdominal pain, hematuria, abdominal mass and so on. computed tomography (CT) plays an important role in the diagnosis of rEWs, and the typical manifestation is a large heterogeneous soft tissue density mass, with a specific "septum-like" enhancement in contrast-enhanced scan. The 2-year overall survival rate of rEWs was 48%, with a median survival time of 18 months. "Septum-like" enhancement on CT can be used as a relatively specific sign for the differential diagnosis of rEWs from Wilms tumor and neuroblastoma. The maximum diameter of the rEWs was usually greater than 10 cm, the clinical symptoms of weight loss, metastasis at diagnosis, tumor thrombogenesis of renal vein or/and inferior vena cava tumor, and the failure to undergo radical nephrectomy were the factors of poor prognosis. The incidence of primary rEWs is low and the prognosis is poor. Early diagnosis and radical nephrectomy combined with chemotherapy is the key to improve the prognosis of patients, and CT plays an important role in early diagnosis.

A rare radiotherapy-sensitive primitive neuroectodermal tumor with APC gene amplification in an adult: a case report and literature review

Primitive neuroectodermal tumor (PNET) of the lung is rare in adults, and treatment options vary. We herein describe the disease course and follow-up of PNET in an adult. A 27-year-old man was admitted to our hospital because of cough and headache, and whole-exome sequencing revealed positive expression of the EWSR1-FLI1 fusion gene and amplification of the APC gene. Although the patient received multidisciplinary treatment including chemotherapy regimens of etoposide plus cisplatin; focal radiotherapy focusing on the cerebrum, lung, and kidneys; and a subsequent palliative gastrointestinal operation, he eventually died of multiple organ functional failure. His overall survival period was 18 months, and his progression-free survival period was 4 months. During the treatment, the patient showed remarkable sensitivity to radiotherapy. In conclusion, PNET of the lung in adult patients is extremely rare, and the prognosis is very poor. Involvement of a multidisciplinary team in the development of personalized therapeutic strategies is essential. This patient with APC gene amplification showed excellent sensitivity to radiotherapy for intrapulmonary and intracranial lesions, suggesting that APC gene amplification may be related to radiotherapy sensitivity. However, further clinical research is needed.

Primary and metastatic primitive neuroectodermal tumor of the heart: A systematic review

OBJECTIVE

Primary and metastatic primitive neuroectodermal tumors of the pericardium are uncommon. Two cases are presented and discussed.

METHODS

The cases of a 17- and 38-year-old male patients with neuroectodermal tumors of the pericardium are presented. In addition, a systematic review was performed according to the Preferred Reporting Items and checklist for Systematic reviews and Meta-Analyses (PRISMA). All selected articles' quality assessment was done using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Case Reports.

RESULTS

The systematic review yielded 29 patients with primary or metastatic PNET. Two patients underwent cardiac transplantation. It seems that unlike considering total resection in other organs, pericardiectomy in PNET patients with pericardial origin may lead to further invasion of the lesions, and it is not recommended. The average disease-free follow-up was 10 months. The combination of neoadjuvant and adjuvant chemotherapy along with surgery and radiotherapy offered the best disease-free outcomes.

CONCLUSION

Neuroectodermal heart tumors are rare, aggressive tumors requiring chemotherapy and radiotherapy in association with tumor resection surgery to have the best disease-free duration.

Genotypes versus phenotypes: The potential paradigm shift in the diagnosis and management of pediatric neoplasms

The gold standard of cancer diagnosis has long been based on histological characteristics. With the rapid advancement of genetic medicine, such standard algorithm of diagnostic approach is facing a challenge. The genetic findings have been changed from being a “supporting character” into the role of a “main character”. More and more disease diagnosis and classification has to be defined by genetic basis. In this article, we focus on the challenges in the field of pediatric oncology. We cited 2 scenarios where genetic information plays a pivotal role in identifying the underlying pathology. The first scenario is that same genetic mutation can lead to variable clinical phenotypes, this includes EWSR1‐PATZ1 fusion related neoplasms; BCOR neoplasms; and GATA‐2 deficiency related immunodeficiency and myelodysplastic syndrome. Another scenario is relatively more common that is the same clinical and histopathological phenotype with different underlying genotypes. The genotypes actually impact on the treatment response and outcome. We used medulloblastoma as an example. In fact, we can also find similar scenario in many pediatric cancers such as Ewing sarcoma, ependymoma, etc. The essence of this article is to remind clinicians of the rapid development in genetic medicine and it has been reshaping the landscape of the modern disease classification and therapeutic approach. In the near future, it may even lead to a paradigm shift in our disease diagnostic algorithm.

Primitive neuroectodermal tumor incidence, treatment patterns, and outcome: An analysis of the National Cancer Database

BACKGROUND

Primitive neuroectodermal tumors (PNETs) comprise less than 1% of all sarcomas. The rarity of this disease has resulted in a paucity of information about disease process and management. This study sought to evaluate the incidence, treatment patterns, and outcomes among patients with PNET.

METHODS

The National Cancer Database was queried for diagnoses of PNET between 2004 and 2014. Patients were dichotomized based on tumor type (central [cPNET] vs peripheral [pPNET]). Demographic, tumor, treatment, and outcome variables were analyzed for the entire patient cohort and by type of PNET.

RESULTS

White (86.4%) males (56.6%) represented the majority of patients. The incidence of PNET remained stable over the study period (r²  = 0.0821). A total of 70.7% underwent surgical resection of the primary site, 50.3% received radiation, and 74.7% received systemic chemotherapy. Compared to those with pPNET, patients with cPNET more often received radiation treatment (P < .001), primary tumor resection (P < .001), and experienced increased 90-day mortality (P < .014).

CONCLUSION

cPNET and pPNET are rare and aggressive malignancies that tend to arise in White males. Multimodal treatment including surgery, chemotherapy, and radiation is conventional. Patients with cPNET more often receive radiation and primary tumor resection with increased 90-day mortality.

Left renal Ewing's sarcoma: A case study and a review of imaging literature

Extra-skeletal Ewing's sarcoma is among the rarest tumors in adults. The primary sites of the tumor dictates symptoms and signs, thus early treatments are compromised when more common tumors are lined up as differentials by the location. We present a case of a 35-year-old pregnant female who developed a renal Ewing sarcoma during pregnancy. A prior simple left kidney cyst in an ultrasound with no tumor signs was spotted. A month after her cesarean section she visited a doctor when she was sent and admitted for surgery with renal cell carcinoma as the primary diagnosis to the Firoozgar hospital. Histology confirmed the final diagnosis. To this end, she completed the standard chemotherapy for the renal Ewing sarcoma with pulmonary metastasis when she was re-evaluated for the general bone pain, diagnosed with multiple bone metastases, and ultimately approached her palliative care. She expired after 2 months. This study demonstrates: a gently progressive mass; palpable in late stages; introduced rise in mean corpuscular volume and lactate dehydrogenase with no drop in the hematocrit. In conclusion, any random parenchymal and/or cortical thickening in primary ultrasound and/or computed tomography demonstrating a cyst—whether displaying internal echo or not— with suggested signs should be furtherly evaluated.

Cytogenetic characterization of the malignant primitive neuroectodermal SK-PN-DW tumor cell line

Background

The SK-PN-DW cell line was established in 1979 and is commercially available. Despite the use of this cell line as an in vitro model for functional and therapeutic studies of malignant primitive neuroectodermal tumor (PNET), there is a lack of complete information about the genetic alterations that are present at the cytogenetic level. Thus, the current study aimed to characterize the cytogenetic profile of this cell line.

Methods

Routine G-banded chromosome analysis, fluorescence in situ hybridization, and oligonucleotide array comparative genomic hybridization assays were performed to characterize the chromosomal changes in this cell line.

Results

The G-banded karyotype analysis showed that the number of chromosomes in this cell line ranged between 36 and 41. Importantly, all cells displayed a loss of chromosomes Y, 11, 13, and 18. However, some cells showed an additional loss of chromosome 10. Additionally, the observed structural changes indicated: a) unbalanced translocation between chromosomes 1 and 7; b) translocation between chromosomes 11 and 22 at breakpoints 11q24 and 22q12, which is a classical translocation that is associated with Ewing sarcoma; c) a derivative chromosome due to a whole arm translocation between chromosomes 16 and 17 at likely breakpoints 16p10 and 17q10; and d) possible rearrangement in the short arm of chromosome 18. Moreover, a variable number of double minutes were also observed in each metaphase cell. Furthermore, the microarray assay results not only demonstrated genomic-wide chromosomal imbalance in this cell line and precisely placed chromosomal breakpoints on unbalanced, rearranged chromosomes, but also revealed information about subtle chromosomal changes and the chromosomal origin of double minutes. Finally, the fluorescence in situ hybridization assay confirmed the findings of the routine cytogenetic analysis and microarrays.

Conclusion

The accurate determination of the cytogenetic profile of the SK-PN-DW cell line is helpful in enabling the research community to utilize this cell line for future identity and comparability studies, in addition to demonstrating the utility of the complete cytogenetic profile, as a public resource.

Long-term survival of a patient with a large adrenal primitive neuroectodermal tumor: A case report

BACKGROUND

Adrenal primitive neuroectodermal tumor (PNET) is an extremely rare malignant tumor with poor prognosis and of neural crest origin. Herein, we report a case of adrenal PNET and summarized its clinical and pathological characteristics on the basis of 16 patients reported recently.

CASE SUMMARY

A female patient aged 25 years presented with right lumbago for 12 mo, and pre-operative computed tomography showed a huge right adrenal mass. She received tumorectomy, and post-operative pathological examination showed adrenal PNET. After surgery, she underwent adjuvant chemotherapy and was followed up 31 mo after surgery. She received brachytherapy for right paracolic and hepatic metastases. She was alive and followed up for 60 mo. In available studies, only 57.14% (4/7) and 44.44% (4/9) were positive for the expression of neuron-specific enolase and synaptophysin, respectively, although CD99 expression was found in all the patients (100%; 10/10).

CONCLUSION

It is concluded that adrenal PNET is very rare and highly malignant, and histology is a golden standard in its diagnosis. Surgery and adjuvant therapy is the main treatment.

Scrotal Peripheral Primitive Neuroectodermal Tumor

The peripheral primitive neuroectodermal tumor (pPNET) is a rare malignant tumor originating from neuroectoderm that usually occurs in children or adolescent and is frequently located in the extremities, chest cavity, pelvic cavity and chest wall. We present a rare case of an 84-year-old man with a history of pPNET in the scrotal sac, to our knowledge not previously published in the literature. The presence of a large irreducible mass in the inguinal sac forced to exclude a tumor. Ultrasound and MRI are very useful modalities to assess the location of the mass, its dependency from any organ and the tumoral internal structure. Molecular imaging with the detection of EWS-FLI1 fusion transcripts is useful for the diagnosis and differential diagnosis of Ewing sarcoma/pPNETs.

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.

Peripheral primitive neuroectodermal tumor in masseter muscle

Primitive neuroectodermal tumor is a member of malignant small round cell tumors. These tumors especially originate from the central and autonomous nervous system. However, these tumors may be originated from peripheral tissues and are called peripheral primitive neuroectodermal tumor. A 14-year-old girl attended to the Ear Nose Throat Clinic with the complaint of progressive painless swelling mass for 2 months on the right side of the face. Neck magnetic resonance imaging showed 3.5 × 2.5 × 2-cm isointense mass on T1 and hyperintense on T2 sequences. There was no pathological lymphadenopathy on computed tomographic scan. As a result of mandibular cortical invasion seen on computed tomographic scan, radical surgical excision was decided as surgical treatment. Total parotidectomy with preserving facial nerve and partial mandibulectomy with a 2-cm margin of safety were done, and reconstruction plaque applied to the mandible. Two lymph nodes were seen at the submandibular region. For this reason, prophylactic supraomohyoid neck dissection had also been performed. Pathological assessment proved the diagnosis of PNET, and chemoradiotherapy was planned for the patient.To our knowledge, this is the second reported case in literature. In this present case, peripheral neuroectodermal tumor in the masseter muscle and its diagnosis and treatment process were reported with literature review.

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.

Radiological and clinical findings of osseous peripheral primitive neuroectodermal tumors

Peripheral primitive neuroectodermal tumor (pPNET) is a rare and highly malignant undifferentiated type of tumor. The aim of the present study was to analyze the computed tomography (CT), magnetic resonance imaging (MRI) and clinical findings of osseous pPNET. The present study retrospectively analyzed the clinical data and CT findings from 15 patients with osseous pPNET; the MRI findings from 11 of these 15 patients were confirmed by histopathological examination. The 15 patients included 9 men and 6 women. The mean patient age was 29 years (range, 16-64 years) and 11 cases were aged <30 years. A CT scan was performed in 15 cases and the findings included a lytic lesion (13 cases), a lytic lesion with irregular sclerosis and dilation (2 cases), a soft tissue mass (15 cases), calcification (2 cases) and periosteal reaction (5 cases). A total of 9 cases of soft tissue mass were heterogeneous, with different sizes of lower-density necrotic areas. An enhanced MRI scan was performed in 11 cases. On T1-weighted images (WI), the soft tissue mass was isointense (8 cases) and marginally hyperintense (3 cases). On T2WI, aggressive soft tissue masses were heterogeneous iso- or hyperintense (11 cases). On contrast-enhanced T1WI, marked heterogeneous enhancement was present in 10 cases and intermediate heterogeneous enhancement in 1 case. The results indicated that osseous pPNET mainly affects male adolescents and young adults. The CT findings of osseous pPNET were destructive lesions with a soft tissue mass and, occasionally, with periosteal reaction. The tumor was often isodense, with patchy hypodense areas. Tumor calcification was uncommon. The MRI findings were those of an aggressive soft tissue mass exhibiting isointensity on T1WI and iso- or hyperintensity on T2WI, with marked heterogeneous enhancement. Although the imaging characteristics of pPNETs may be non-specific, CT and MRI may be useful in delineating the extent of the tumor, identifying distant metastases, predicting resectability and monitoring treatment.

Primitive neuroectodermal tumor in the spinal canal: A case report

Primitive neuroectodermal tumors (PNETs) are rare tumors of uncertain histogenesis that occur predominantly in children and young adults. The current study reports a case of PNET in a 60-year-old female, which presented clinically as an intraspinal tumor, causing symptoms of lower back pain, numbness and pain in the right lower extremity. The patient underwent tumorectomy. Following primary therapy, the symptoms of spinal cord compression were relieved. The patient underwent several courses of radiotherapy following surgery but refused to continue with chemotherapy. After a further four months, the tumors recurred and the patient succumbed to the disease.

[Peripheral PNET of mesenteric location]

Les tumeurs neuroectodermiques primitives (PNET) mésentériques sont exceptionnelles. Elles appartiennent au groupe des tumeurs neuroectodermiques primitives périphériques et sont assimilées histologiquement aux sarcomes d'Ewing. Le diagnostic repose essentiellement sur les résultats immunohistochimiques et cytogénétiques. Nous nous proposons, à travers un cas de PNET à localisation mésentérique de revoir l'ensemble des aspects cliniques, radiologiques, histopathologiques et thérapeutiques de ce groupe de tumeur.

Rapidly progressive primitive neuroectodermal tumor of the prostate: A case report and review of the literature

The present study reports a rare case of primitive neuroectodermal tumor (PNET) of the prostate. A 23-year-old male presented to Oita Medical Center (Oita, Japan) with the complaint of dysuria and anal pain. A large mass in the prostate and a number of swollen lymph nodes in the pelvic region were identified by a computed tomography scan and magnetic resonance imaging. The patient was, thus, admitted to Oita University Hospital (Yufu, Japan), where a biopsy of the prostate gland was performed. Histological analysis revealed small round cells that were positive for MIC-2 expression and fluorescent in situ hybridization analysis detected a translocation involving Ewing sarcoma breakpoint region 1 at chromosome 22q12. Thus, a diagnosis of PNET of the prostate was established. Systemic chemotherapy was the selected treatment, however, a poor response was obtained. The patient succumbed approximately four months after the initial onset of symptoms. PNET of the prostate has been reported in eight cases worldwide; in comparison, the present case exhibited the most unsatisfactory outcome.

The imaging features of meningeal Ewing sarcoma/peripheral primitive neuroectodermal tumours (pPNETs)

OBJECTIVE

To explore the imaging features of meningeal Ewing sarcoma/peripheral primitive neuroectodermal tumours (pPNETs).

METHODS

The imaging features and pathological characteristics of eight cases of surgically and pathologically confirmed Ewing sarcoma/pPNET were analysed retrospectively in light of recent literature on the disease.

RESULTS

The peak age was between 10 and 20 years. The lesions tended to be spindle shaped and dural based, usually widely so. CT showed that the lesions had slightly uneven high density in five cases and iso-low mixed density in three cases; marked heterogeneous enhancement was seen in all cases after contrast injection. MRI of the lesions showed varying proportions of isointense and hypointense signal in all cases on unenhanced T1 weighted imaging and varying proportions of isointense and hyperintense signal on T2 weighted imaging. After contrast injection, marked heterogeneous enhancement was seen in all cases; three cases showed a short and nodular dural tail and five cases showed adjacent skull erosion and osteolysis. Pathological results included high cell density, haemorrhage and necrosis. The cells resembled lymphocytes and spindle cells with transparent cytoplasm. CD99 and vimentin were expressed by all tumour cells.

CONCLUSION

Features of meningeal Ewing sarcoma/pPNETs include peak incidence at 10-20 years of age, a broad connection to the meninges, a thick dural tail involved with tumour, skull and scalp erosion and early metastasis. Necrosis and cystic changes are the common histological findings.

ADVANCES IN KNOWLEDGE

The imaging features of meningeal Ewing sarcoma/pPNETs have not been reported. The study helps to identify meningeal Ewing sarcoma/pPNETs and meningioma.

Askin tumor: CT and FDG-PET/CT imaging findings and follow-up

The aim of the study was to describe the imaging findings of Askin tumors on computed tomography (CT) and fluorine 18 fluorodeoxyglucose-positron emission tomography (FDG-PET/CT).Seventeen cases of Askin tumors confirmed by histopathology were retrospectively analyzed in terms of CT (17 cases) and FDG-PET/CT data (6 cases).Fifteen of the tumors were located in the chest wall and the other 2 were in the anterior middle mediastinum. Of the 15 chest wall cases, 13 demonstrated irregular, heterogeneous soft tissue masses with cystic degeneration and necrosis, and 2 demonstrated homogeneous soft tissue masses on unenhanced CT scans. Two mediastinal tumors demonstrated the irregular, heterogeneous soft tissue masses. Calcifications were found in 2 tumors. The tumors demonstrated heterogeneously enhancement in 16 cases and homogeneous enhancement in 1 case on contrast-enhanced scans. FDG-PET/CT images revealed increased metabolic activity in all 6 cases undergone FDG-PET/CT scan, and the lesion SUVmax ranged from 4.0 to 18.6. At initial diagnosis, CT and FDG-PET/CT scans revealed rib destruction in 9 cases, pleural effusion in 9 cases, and lung metastasis in 1 case. At follow-up, 12 cases showed recurrence and/or metastases, 4 cases showed improvement or remained stable, and 1 was lost to follow-up.In summary, CT and FDG-PET/CT images of Askin tumors showed heterogeneous soft tissue masses in the chest wall and the mediastinum, accompanied by rib destruction, pleural effusion, and increased FDG uptake. CT and FDG-PET/CT imaging play important roles in the diagnosis and follow-up of patients with Askin tumors.

Three cases of a peripheral primitive neuroectodermal tumor diagnosed using computed tomography or magnetic resonance imaging

The present study describes the findings from three cases of peripheral primitive neuroectodermal tumors (PNETs) diagnosed using computed tomography (CT) or magnetic resonance imaging (MRI). The patients were all diagnosed with PNETs of the peripheral central nervous system. All the lesions were soft-tissue masses with cystic degeneration. The CT images revealed that the lesions were large and inhomogeneous, with unclear borders and cystic degeneration. The surrounding tissues and structures were compressed against each other. Following the enhancement of the CT, the solid components of the tumors were enhanced, whereas the cystic components did not show enhancement. Following the enhanced MRI, irregular enhancement was noted in the solid components and the cystic and solid masses showed unclear borders. The surrounding tissues were compressed. The solid components of the tumors were enhanced, whereas the cystic components showed no enhancement. Based on these observations, PNETs were diagnosed. Thus, a CT or MRI is mandatory for the precise diagnosis of a peripheral PNET.

Clinical, pathological, and imaging characteristics of primitive neuroectodermal tumors of the spine

Primitive neuroectodermal tumors (PNETs) located in the spine are extremely rare, and information concerning these tumors in the medical literature is limited to single case reports. This pictorial essay presents the clinical, pathological, and imaging characteristics of PNET of the spine.

Imaging characteristics of primary spinal primitive neuroectodermal tumors. A report of five cases and literature review

Primary spinal primitive neuroectodermal tumors (PNETs) are rare and classified into peripheral and central types because the treatment strategy and outcome are different. This study describes five cases of primary spinal peripheral type PNETs. Magnetic resonance imaging showed large extradural masses in the cervical and thoracic spine with bony invasion and paraspinal extension in four cases and a transdural mass in the sacral spinal canal in one case. We also briefly summarize the imaging characteristics of 36 peripheral type and six central type primary spinal PNETs in the literature.

Radiological and clinicopathological features of pPNET

PURPOSE

To analyze the radiological and clinicopathological features of peripheral primitive neuroectodermal tumor (pPNET).

MATERIALS AND METHODS

We retrospectively reviewed the computed tomography (CT) and magnetic resonance (MR) imaging of 14 cases of pPNET confirmed immunohistochemically. Relevant clinical data was also obtained.

RESULTS

Of 14 cases, there were 10 male and 4 female with a mean age of 28 years. The main symptoms were the aggravated pain of the lesion site and enlarged palpable masses. Fourteen lesions were located in the chest wall (n = 4), retroperitoneum (n = 3), pelvic cavity (n = 2), intraspinal area (n = 2), nasal cavity (n = 1), leg ( n= 1) and iliac bone (n = 1). Eleven lesions originating from the soft tissue mainly demonstrated large and infiltrative mass with (n = 4) or without (n = 7) bony invasion. Ten cases of them showed heterogeneous density with patchy, necrotic foci and moderate heterogeneous enhancement. Four of them with large cystic area contained irregular septations within them. Two intraspinal cases had extradural lesions, extending through the intervertebral foramen and formed paraspinal soft tissue masses with vertebral destruction. The case within iliac bone demonstrated extensive mixed (lytic/osteoblastic) lesion with large adjacent soft tissue mass. After surgery or therapy, 10 patients died of local recurrences or metastases.

CONCLUSION

The diagnosis of pPNET should be suggested in young patient when imaging depicts a large, ill-defined, soft-tissue mass containing area of cystic degeneration with internal septations and extending along the neural route and nearby the middle of the trunk. The key for correct diagnosis is to inosculate imaging to clinical data.

Sarcomas of abdominal organs: computed tomography and magnetic resonance imaging findings

Sarcomas originating from abdominal organs are extremely rare, and literature in which investigators focus on their imaging features is scarce. This article aims to review the computed tomography and magnetic resonance imaging features of these rare tumors and to help in clinical diagnosis. Various sarcomas (eg, angiosarcoma, undifferentiated embryonal sarcoma, leiomyosarcoma, carcinosarcoma, rhabdomyosarcoma) originating, respectively, from different abdominal visceral organs (liver, pancreas, spleen, kidney, adrenal gland, uterus, and prostate gland) are reviewed along with cases we encountered.

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

BACKGROUND

We analyze the computed tomography (CT) findings of a peripheral primitive neuroectodermal tumor (pPNET) arising in the abdominopelvic cavity and to improve understanding of the CT images of the tumor.

MATERIALS AND METHODS

Twelve cases of pPNET confirmed by histopathology were analyzed retrospectively. Image characteristics of CT scanning were analyzed and compared with the pathology of the tumors.

RESULTS

There were 8 males and 4 females with mean age of 34.5 years. Unenhanced CT images showed large heterogeneous and ill-defined or well-defined masses with multiple patchy hypodense areas. The average diameter was 9.8 cm (range 4.0-17.2 cm). Contrast-enhanced CT images showed variable heterogeneous contrast enhancement with multiple non-enhancement areas. 3 cases revealed metastasis and 4 cases invaded into adjacent organs. Pathology showed areas of degeneration and necrosis in all tumors. Cluster of differentiation 99 and neurone specific enolase were detected positive in 11 and 12 cases, respectively.

CONCLUSIONS

In conclusion, pPNET in the abdominopelvic cavity likely affects young adults with a slight male preponderance and tend to be large and aggressive. Although CT findings are nonspecific and variable, a large ill-defined or well-defined heterogeneous mass with multiple patchy hypodense areas reflecting their cystic degeneration and necrosis on pathology examination may suggest the diagnosis of pPNET.

Intracranial meningeal hemangiopericytomas in children and adolescents: CT and MR imaging findings

Intracranial meningeal hemangiopericytomas in children and adolescents are prone to bleeding during surgery. CT and MR imaging may serve a role in preoperative diagnosis. The purpose of this report was to describe the radiologic findings in 9 pathologically proved cases of intracranial meningeal hemangiopericytomas in children and adolescents. The average duration of symptoms was short (mean, 4.0 months; median, 1.5 months). The intraoperative blood loss was large (mean, 3561 mL; median, 1000 mL). Tumors were extra-axial, irregularly multilobular, and hypervascular. Radiologically, they showed mixed attenuation on precontrast CT images, heterogeneous signal intensity on precontrast MR imaging, and marked and heterogeneous enhancement on postcontrast MR imaging. Bone erosion was sometimes present, but hyperostosis was not present. On MR imaging, multiple signal intensity voids of vessels were observed in 100% (8/8) of tumors with AVM-like signal intensity flow voids in 25% (2/8) of tumors. These results suggest that CT and MR imaging findings may be helpful for preoperative diagnosis.

Imaging findings in mandibular primitive neuroectodermal tumour: a report of a rare case and review of the literature

Primitive neuroectodermal tumours (PNETs) are aggressive undifferentiated tumours that occur mainly in the central nervous system (CNS). Reviewing the literature, only six cases of primary PNET of the mandible have been reported. These rare tumours are usually overlooked in clinical practice. An 18-year-old woman who presented with dental caries and left cheek swelling was initially diagnosed with facial cellulitis, but the swelling persisted despite adequate intravenous antibiotic therapy. Subsequent ultrasound and MR examinations revealed a tumour originating from the left mandibular ramus. The ultrasonography-guided percutaneous core needle biopsy confirmed the diagnosis of peripheral PNET. The radiographic features of mandibular PNETs are similar to those of PNETs in other regions, except for haemorrhage, necrosis and calcification. In addition, this is the first reported case with sonographic and MR images of this rare tumour, and the first case that was diagnosed based on the ultrasonography-guided percutaneous core needle biopsy. Using these image characteristics, mandibular PNETs can be diagnosed more accurately.

Therapy and outcome of primitive neuroectodermal tumor of the jaw

Data pertaining to outcomes in jaw primitive neuroectodermal tumor (PNET) are lacking. Eleven cases of jaw PNET (five maxillary and six mandibular) were treated at our cancer center with the same chemotherapeutic agents from June 2003 to January 2009. Four patients underwent surgery after neoadjuvant chemotherapy and all received local radiotherapy. At median follow-up of 56 months (range: 19-77 months), 7/11 patients are in sustained remission. There was no difference in outcome with respect to site of tumor, and whether surgery was performed or not. These results support the use of chemoradiation as initial modality of treatment rather than going for extensive and mutilating surgery.

Computed tomography and magnetic resonance imaging findings of peripheral primitive neuroectodermal tumors of the head and neck

PURPOSE

We aimed to analyze the computed tomography (CT) and magnetic resonance imaging (MRI) findings of peripheral primitive neuroectodermal tumor (pPNET) of the head and neck.

METHODS

Eight patients with pPNET of the head and neck confirmed by histopathological examination were analyzed retrospectively.

RESULTS

The average patient age was 8 years. The tumor location in the 8 patients was as follows: maxillofacial region (right, 2; left, 1), left maxillary sinus (1), right masticator space (1), left carotid space (1), right infratemporal fossa (1), and left parotid gland (1). All 5 patients who underwent CT demonstrated ill-defined soft masses and no calcification. Three patients with tumors in the maxillofacial region showed homogeneous small masses and a mild enhancement. The patient with left maxillary sinus tumor showed a heterogeneous mass with patchy, necrotic foci and mild heterogeneous enhancement. The patient with right masticator space tumor showed a heterogeneous mass, and marked heterogeneous enhancement. The T1-weighted images of the patients with right infratemporal fossa, left carotid space, and left parotid gland tumors were isointense. The T2-weighted images were heterogeneous and mildly hyperintense in 2 patients and hyperintense in 1 patient. Heterogeneous intermediate enhancement was demonstrated in 2 patients and mild ring enhancement in 1 patient.

CONCLUSION

The imaging features of pPNET of the head and neck are non-specific. An ill-defined, aggressive mass and variable enhancement on CT and MR images may suggest the diagnosis of pPNET. Peripheral PNET should be included in the differential diagnosis of children and adolescents' regional tumors.

Imaging findings of abdominal peripheral primitive neuroectodermal tumor: report of four cases with pathological correlation

Peripheral primitive neuroectodermal tumors (peripheral PNETs) are rare in the abdomen. We report the imaging findings of four peripheral PNETs arising in the abdomen. Three were ill-demarcated tumors and one was a well-demarcated tumor, with extensive local invasion and lymph node metastasis in two cases, respectively. The tumors are of inhomogeneous attenuation and heterogeneous enhancement after intravenous administration of contrast materials. Although their imaging manifestations cannot distinguish them from other sarcomas, recognition of these imaging features may be helpful in suggesting the possibility of peripheral PNETs in some cases.

Therapy and outcome of orbital primitive neuroectodermal tumor

Primary orbital primitive neuroectodermal tumor (PNET) is rare with no reported series. We report six cases of orbital PNET treated at a tertiary care oncology center in northern India from 2003 to 2008. None of them had distant metastases. All were treated with neoadjuvant chemotherapy followed by exenteration in two, radiotherapy and adjuvant chemotherapy in five cases. Three out of six achieved complete remission at end of therapy with globe salvage in three and vision in two cases. Chemoradiotherapy may help us to avoid mutilating surgery in large or locally advanced tumors, allowing preservation of vision or the globe.

Imaging features of peripheral primitive neuroectodermal tumours

Primitive neuroectodermal tumours (PNETs) are a rare group of extremely aggressive small round cell tumours. Most commonly, they occur within the central nervous system. However, they also sporadically involve extracranial sites (peripheral PNETs). The chest wall is the most common of these sites, the imaging features of which have been well described in earlier studies. The present pictorial essay illustrates the imaging features of PNETs at various extracranial locations.

[Late mediastinal metastasis of Ewing's sarcoma of tibia]

Peripheral neuroectodermal tumors constitute a large spectrum of small round cell tumors among which Ewing's sarcoma is the most undifferentiated type. They are rare tumors which often concern young people and generally occur in bone tissue. Their metastatic potential is high, generally early, and rarely after five years. We report the case of a 45-year-old woman who presented a mediastinal metastasis eight years after the primitive tumor of tibia. The diagnosis was made on small core biopsies obtained by CT punction, and was based on morphologic analysis, immunohistochemistry, and confirmed by molecular biology. The presence of metastasis is the main prognostic factor. Despite therapeutic progress, the global survival rate of metastatic patients is still poor.

Radiological imaging features of non-uterine leiomyosarcoma

Leiomyosarcomas are unusual soft-tissue tumours that occur in the retroperitoneum, peripheral soft tissues, gastrointestinal and genito-urinary tracts, vessels and (rarely) in bone. The aim of this pictonal review is to delineate the more specific radiological features that would suggest a radiological diagnosis of leiomyosarcoma prior to biopsy.