Peripheral Neuroectodermal Tumor Research Articles

Peripheral neuroectodermal tumour: a clinicopathological and immunohistochemical study of seven cases in Sri Lanka

The clinicopathological and immunohistochemical features of 7 cases of peripheral neuroectodermal tumour were documented. Children and adults were affected. The tumours were found in both bone and soft tissue. All tumours were positive for neurone specific enolase. Some were positive for PGP 95 neurofilaments and 0-13, in addition. Cytoplasmic glycogen was variable. Some tumours showed good neural differentiation. In general the tumours had an aggressive behaviour.

#633 Congenital peripheral neuroectodermal tumor presenting as disseminated cutaneous disease

#633 Congenital peripheral neuroectodermal tumor presenting as disseminated cutaneous disease

Hypersensitivity after ifosfamide administration

The toxicity profile of the alkylating anti-cancer drug ifosfamide is quite well known. However, up to now only a few cases of hypersensitivity as an attributed adverse effect of ifosfamide have been described in literature. This article describes the history of a woman suffering from a primary peripheral neuroectoder mal tumor (PNET) who was admitted to our hos pital for chemotherapy. Treatment was given ac cording to the EICESS-protocol (European Intergroup Cooperative Ewing's Sarcoma Study) with the following anti-cancer drugs: etoposide, doxorubicin, vincristine, and ifosfamide/mesna. Af ter ifosfamide administration an acute hypersensi tivity reaction was seen consisting of redness in the face and on the left arm, back and chest, and bronchoconstriction. Subsequent intravenous ad ministration of the anti-histaminic clemastine (2 mg) and dexamethasone (5 mg) before ifosfamide administration on a second occasion did not pre vent these reactions. After substituting cyclophos phamide for ifosfamide in consecutive courses no untoward reactions occurred.

Vla and alpha 6 beta 4 integrin expression in neuroendocrine carcinomas of the skin (their xenografts on nude mice and a corresponding primary culture).

Immunohistological expression of VLA1-5 and alpha 6 beta 4 integrins have been studied in 21 cases of primary neuroendocrine carcinomas of the skin (NECS), three xenografts on nude mice and one NECS cell culture. The phenotypic properties of NECS cells were largely maintained in NECS grafted on athymic nude-mice and in the corresponding cell line. Our results indicate that alpha 1 beta 1 and to a lesser extent alpha 3 beta 1, alpha 5 beta 1 are the main integrins expressed in NECS. In addition, VLA2, 4 and alpha 6 beta 4 are heterogeneously expressed in the same group of tumors and very sparsely present. These data suggest that like neuroblastoma and primitive peripheral neuroectodermal tumor (pPNET) the absence or the heterogeneous distribution of such integrins is correlated with the aggressive behaviour of NECS although long-term follow-up was not available for our cases. On the other hand, the alpha 1 expression could be regarded as a novel marker for differential diagnosis between NECS (alpha 1+) and pPNET (alpha 1-). The alpha 1 beta 1, alpha 2 beta 1, alpha 3 beta 1, alpha 5 beta 1 heterodimers in the 21 NECS studied showed an uniform pericellular staining of both the peripheral cells and central cells of the tumor islands. The predominant expression of alpha 1 beta 1 is consistent with the hypothesis of a primitive epithelial totipotential origin in NECS.

Immunostaining of the p30/32 MIC2 antigen and molecular detection of EWS rearrangements for the diagnosis of Ewing's sarcoma and peripheral neuroectodermal tumor

The identification of Ewing's sarcoma (ES) and peripheral neuroectodermal tumor (PNET) among other small round cell tumors (SRCTs) is a critical issue in musculoskeletal pathology because of the lack of clearly distinctive morphological features. In this study, the authors have compared advantages and limits of two procedures that were recently suggested as additional tools for the identification of ES/PNET, the analysis of p30/32 MIC2 antigen by immunohistochemistry, and the evaluation of the fusion products of two specific chromosomal aberrations, the t(11;22)(q24;q12) and the t(21;22)(q22;ql2), by reverse transcriptase-polymerase chain reaction (RT-PCR). The authors have analyzed the expression of p30/ 32 MIC2 in 28 cell lines and in 90 tumor samples. p30/32 MIC2 was highly expressed in ES/PNET but was also present in all the other cell types. The broad spectrum of positivity for p30/32 MIC2 in SRCTs of bone was substantially confirmed by the analysis of tissue samples. In the same material, the authors have evaluated the presence of t(11;22) or t(21;22) transcripts ( EWS/FLI-1 and EWS/ERG, respectively) by RT-PCR. These transcripts were found in all the cell lines and tissue samples of ES/PNET, but not in other tumors. The authors' results question the use of p30/32 MIC2 immunostaining alone for the identification of ES/PNET and suggest the adoption of RT-PCR as an advantageous alternative. Molecular diagnosis of ES/PNET by RTPCR is highly specific and can be applied to small amounts of tissue. Moreover, RNA extracted from paraffin-embedded specimens was shown to be suitable for RT-PCR analysis, thus enabling analysis of archival material.

Peripheral primitive neuroectodermal tumors. CT and MRI evaluation

The clinical, radiographic, and pathologic features of 17 patients with documented peripheral primitive neuroectodermal tumor (PNET) were evaluated in a retrospective study. The age at diagnosis ranged from 9 months to 46 years (median, 15.8 years). Primary sites of involvement were the abdomen (n = 8), extremities (n = 5), chest (n = 1), temporal bone (n = 1), maxilla (n = 1), and diploe (n = 1). At the time of diagnosis, six patients had distant metastases; all of these patients died, with an average survival of 8.8 months. Radiologic workup included standard radiographs, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and bone scintigraphy. The radiographic appearance of these tumors was not specific for differentiation of PNETs from other types of bone and soft tissue tumors. The typical appearance resembled large non-calcified, soft tissue masses with cystic or necrotic areas. Heterogeneous enhancement with intravenous contrast agents was evident on CT, as was an intermediate signal intensity on T1-weighted images and hyperintense signal on T2-weighted and STIR sequences. After gadolinium administration, variable enhancement was seen. MRI and CT were useful in predicting resectability, in detecting distant metastases, and in the evaluation of response to treatment. Surgery was performed in all cases, either for definitive diagnosis or for therapy. All patients received combined chemotherapy and radiotherapy and five patients received autologous bone marrow transplantation. Clinical follow-up was obtained over a mean period of 3 years (range 1 day to 6 years). Prognosis was poor with a median survival of 3.4 years. Our experience in 17 patients with peripheral neuroectodermal tumors indicates that although their radiologic features are non-specific, they should be included in differential diagnosis of soft tissue tumors of aggressive behavior, especially in a young age group. CT and MRI are useful in delineating the extent and resectability of tumor and in monotoring treatment.

EWS/FLI-1 fusion transcript detection and MIC2 immunohistochemical staining in the diagnosis of Ewing's sarcoma.

Ewing's sarcoma (ES) and other primitive peripheral neuroectodermal tumors (pPNETs) can present a significant diagnostic problem, as they may morphologically resemble other small round cell tumors (SRCTs) of childhood. However, ES/pPNET is known to carry a characteristic t(11;22)(q24;q12), the detection of which may aid diagnosis. The recent identification of the EWS and FLI-1 genes flanking the translocation break point has enabled reverse transcriptase-polymerase chain reaction (RT-PCR) to be used to detect the putative chimeric transcription factor mRNA produced by the fusion gene. We have assessed the RT-PCR method of detection by examining 40 cases of ES for the presence of EWS/FLI-1 transcripts. Twenty-six (76%) of the 34 cases with intact mRNA yielded fusion transcripts. Four different transcript sizes were detected and two tumors contained two transcripts of different size. No transcripts were detected in a control group of non-ES/pPNET SRCTs. Eight cases with intact mRNA were transcript negative. The MIC2 cell surface antigen, which is reported to be present in over 95% of ES/pPNETs, was present in 32 of 33 tumors (97%), including all 24 EWS/FLI-1 transcript-positive cases examined. Hence MIC2 is a useful screen for ES, with RT-PCR detection of t(11;22) being the optimal method for confirming the diagnosis.

Pathology of Ewing sarcoma

Ewing's sarcoma is a very rare tumor which has, however, attracted much oncological interest since the dramatic improvement of its prognosis under chemotherapy. Its histogenesis has been discussed controversially for a long time, including a possible origin in immature reticulum, myogenous, endothelial and undifferentiated mesenchymal cells. Repeated reports have also suggested a possible neuroectodermal genesis. Convincing arguments, however, have only been brought forward during recent years, since it was found that Ewing's sarcoma and malignant peripheral neuroectodermal tumor share a common chromosome translocation 11;22. In the meantime this hypothesis has been strengthened by numerous cell biological analyses. There seems to be no clear border between Ewing's sarcoma and malignant peripheral neuroectodermal tumors with definite neural differentiation. Histological differential diagnosis of Ewing's sarcoma has been improved by immunohistological methods. In most cases, they can be distinguished from lymphoma (leucocyte common antigen, B and T markers) and embryonal rhabdomyosarcoma (muscle specific actin, desmin) without problems. Apart from that, it is possible nowadays to obtain antibodies against the MIC 2-protein, which is preferably expressed in Ewing sarcoma. The diagnostics of Ewing's sarcoma and the malignant peripheral neuroectodermal tumor have considerably been enriched by the fact that the specific chromosome translocation t(11;22) can be proved molecular biologically. In contrast to the cytogenetic evidence, it is not necessary to establish cell cultures.

Primary cutaneous neuroendocrine tumors: Diagnostic use of cytogenetic and MIC2 analysis

Merkel cell carcinoma (MCC) is a primary cutaneous neoplasm most commonly involving older adults. The cell of origin is thought to be the Merkel cell, a cutaneous neurosecretory cell. However, other neuroectodermal tumors may present in the skin and may be difficult to distinguish from MCC, including peripheral neuroectodermal tumors (PNET) and metastatic small cell carcinoma. We examined a primary cutaneous tumor of an 18-year-old which was strongly positive for cytokeratin (CK), neuron-specific enolase (NSE), and 12E7, an antibody to the protein determined by the MIC2 gene. Electron microscopy showed paranuclear aggregates of filaments and no cytoplasmic processes. These findings were considered to be consistent with MCC. Cytogenetic analysis demonstrated 46,XX,der(1)t(1;3;22)(lqter→pa34::3q28→q11::22q12→qter),der(3)t(1; 3) (pter→q11::1p35-pter),der(22)t(3; 22) (22pter→q11::?3q29→qter). This was confirmed by chromosome painting using probes for chromosomes 1, 3, and 22. Peripheral neuroectodermal tumors (PNETs) show a characteristic translocation involving the same breakpoint on chromosome 22 that was present in this tumor. PNETs can also be CK and NSE positive. The MIC2 gene codes for a surface glycoprotein that has been shown to be very strongly and reliably expressed in PNETs, but not in other small round blue cell tumors and not in small cell carcinoma of the lung. However, MIC2 expression has not been studied in MCC. We investigated the use of MIC2 analysis in the distinction of MCC from PNET. Five additional MCCs were stained with the monoclonal 12E7 antibody, ant one additional tumor showed the strong membranous positivity reported in PNETs. Our data suggest that MIC2 analysis may be useful in differentiating between MCC and PNET However, cases will remain for which the distinction is elusive and cytogenetic analysis may be helpful.

Metastasis of C1300 and TBJ murine neuroblastomas correlates with expression of matrix metalloproteinases.

Because metalloproteinases, specifically type IV collagenases, may mediate metastasis, 72- and 92-kDa collagenase activities were evaluated in two murine neuroblastoma cell lines: non-metastatic C1300 and metastatic TBJ. Zymogram analysis demonstrated that 72- and 92-kDa collagenases were associated only with metastatic TBJ. Three human neuroblastoma cell lines were then evaluated by zymogram and Western blot analyses: 72-kDa collagenase was found in metastatic SK-N-SH and IMR-32, but not in SK-N-MC, which may be a peripheral neuroectodermal tumor and not a neuroblastoma. Therefore, 72- and 92-kDa collagenases may be markers of metastasis in neuroblastoma and may aid in differentiation from other small blue cell tumors.

Ewing's sarcoma and extracranial peripheral neuroectodermal tumors.

Ewing's sarcoma and extracranial primitive neuroectodermal tumors of bone and soft tissue are small round-cell tumors that comprise a family of neoplasms distinguished by a cytogenetic marker that can be detected by reverse transcription and polymerase chain reaction. Based on molecular and immunohistochemical studies, it is generally acknowledged that this is a family of neuroectodermal tumors. Molecular methods allow accurate diagnosis with minimally invasive surgical options, provide a manner to detect minimal residual disease, and begin to shed light on the pathogenesis of these entities. Combined modality treatment regimens continue to improve the outlook for nonmetastatic Ewing's sarcoma and primitive neuroectodermal tumors patients. Patients who present with metastatic disease may benefit from intensive therapy as facilitated by peripheral stem cell and autologous bone marrow rescue programs.

Is esthesioneuroblastoma a peripheral neuroectodermal tumor?

Esthesioneuroblastoma (ENB; olfactory neuroblastoma) is a rare, locally aggressive neoplasm of the sinonasal area and anterior cranial fossa. The histogenesis of the lesion is not clearly delineated, and the broad histological spectrum of ENB has confounded the issue. The location, histological features (neuropil, Homer Wright, and olfactory rosettes), and reported immunocytochemical reactions (neuron-specific enolase (NSE) and chromogranin (CHR) positivity) suggest that ENB may be a neural or neuroendocrine neoplasm derived from the olfactory membrane. Recent demonstration in two of three metastatic putative ENB cell lines of the 11; 22 chromosomal translocation, seen in Ewing's sarcoma (ES) of bone and peripheral neuroectodermal tumors (PNET) of bone and soft tissue, has led to the conclusion that ENB may be closely related histogenetically to PNET. The overwhelming majority of cases of ES and PNET express the protein product of MIC-2, a gene located on the pseudoautosomal region of the X and Y chromosomes. This protein can be identified immunocytochemically by antibodies 12E7, HBA71, and ON13. We studied the expression of MIC-2 using the 12E7 antibody as well as multiple neural markers in 18 ENB samples obtained from the files of The Johns Hopkins Hospital. The patients ranged in age from 19 to 90 years (mean, 47.5; median, 47) and included five men and 13 women. None of the 18 specimens reacted with antibody 12E7, but 16 were positive for NSE, nine reacted to synaptophysin (SYN), and 13 showed antibodies to chromogranin (CHR). Our studies agree with the previous suggestions that ENB is a primitive neural tumor but fail to support the hypothesis that it is a member of the PNET family.

Primitive Neuroectodermal Kidney Tumor: 2 Case Reports and Review of the Literature

Peripheral neuroectodermal tumors are uncommon cancers arising from outside the central nervous system. The urinary system is rarely involved. The differentiation of these tumors from other small cell cancer and neuroblastoma is based on immunohistochemical differences. We report 2 cases of such tumors arising from the renal parenchyma. Tumor behavior and treatment modalities are discussed.

Primitive neuroectodermal tumour of the chest wall

The concept of primitive neuroectodermal tumour (PNET) has been evolving for many years, as has its nomenclature. It was first described as a tumour arising in peripheral nerve, when it was called neuroepithelioma. These tumours are part of the differential diagnosis of malignant small round cell tumours, which include Ewing's sarcoma, rhabdomyosarcoma, neuroblastoma and lymphoma, and which appear as sheets of monotonous small round cells on light microscopy, staining dark blue with haematoxylin and eosin. In the 1970's, reports of tumours displaying neural features introduced new terms such as primitive neuroectodermal tumour and peripheral neuroectodermal tumour. A relationship to the undifferentiated primitive neuroectodermal tumours of the central nervous system in children was assumed by the title of these tumours, although it was recognised that they were not necessarily related to peripheral nerves.

MDM2 and CDK4 gene amplification in Ewing's sarcoma.

Amplification of the MDM2 gene, which maps to chromosome band 12q13 and encodes a p53-binding protein, may result in functional inactivation of p53 and has been observed in various bone and soft tissue sarcomas. Published studies have included few cases of Ewing's sarcoma (ES) or peripheral neuroectodermal tumour (PNET), a tumour group in which alterations of the p53 pathway have so far not been extensively studied. We examined two ES cell lines, RD-ES and SK-ES-1, and 30 specimens from 27 patients (24 ES, 6 PNET; 19 primary, 4 local recurrence, 7 metastasis) for MDM2 gene amplification by Southern blot analysis. All 30 clinical specimens had been confirmed to contain sufficient ES/PNET DNA by the demonstration of a rearrangement of the t(11;22)-associated EWS gene using an EWS cDNA probe on the same blots. MDM2 gene amplification was detected in 3 of 30 specimens (10 per cent), including two ES and one PNET, but in neither of the cell lines. The three cases with amplification were morphologically typical primary tumours. Two of the three cases also showed co-amplification of the CDK4 gene, which encodes a cyclin-dependent kinase and also maps to band 12q13. Clinically, all three cases had metastatic disease at diagnosis, compared with only 1 of 15 MDM2-negative cases where the primary tumour was studied. The difference was statistically significant (P = 0.005), suggesting an association of MDM2 amplification with advanced stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Differential expression of beta 1, beta 3 and beta 4 integrins in sarcomas of the small, round, blue cell category.

Integrins are a large and complex family of membrane spanning alpha beta heterodimeric cell surface glycoproteins mediating cell/cell and cell/matrix interactions. Small, round, blue cell sarcomas (SRBCS) are a group of poorly differentiated tumours of various and in part uncertain histogenesis displaying similar cytomorphology. Among them are rhabdomyosarcomas (RMS), ganglioneuroblastomas [(G)NB], primitive peripheral neuroectodermal tumours (pPNET) and Ewing's sarcomas (ES). Thirty-two SRBCS were studied immunohistochemically for the distribution of beta 1, beta 3 and beta 4 integrins in situ. We found complex and to some extent differential patterns of beta 1, beta 3 and beta 4 integrin subunit expression in different types of SRBCS: all of the sarcomas studied were consistently beta 1+, beta 4-, alpha 2-. Four of nine RMS were completely negative for all other integrin subunits studied while one RMS was alpha 5+ throughout and three RMS were focally alpha 5+. Three RMS expressed the alpha 6 and alpha v chains. In contrast to RMS, pPNET and ES, all of which were alpha 1-, alpha 3-, (G)NB were alpha 3+ and frequently co-expressed alpha 1. The eight pPNET and seven ES studied showed a similarly restricted integrin profile that was limited to the expression of beta 1 and alpha 5 in nearly all cases. In summary, RMS were beta 1+, alpha 1-, alpha 3- and heterogeneously expressed alpha 5 and alpha 6. (G)NB were generally beta 1+, alpha 1+, alpha 3+, alpha 5-, alpha 6-. pPNET and ES were beta 1+, alpha 1-, alpha 3-, alpha 5+, alpha 6-. The data illustrate a complex expression pattern of various integrins in SRBCS, a differential expression pattern of some of the integrin subunits among different types of SRBCS and almost identical integrin profiles in pPNET and ES.

Multiple primitive neuroectodermal tumors

Primitive neuroectodermal tumors are rare, highly aggressive neoplasms that affect both sexes and occur in all age groups. They are a large group of neoplasms with neuroepithelial differentiation, including cutaneous neuroblastomas. Histopathologically they are characterized by a rather uniform population of small, dark cells, with or without Homer Wright rosettes. Immunohistochemically they stain for one or more of the reputed neural markers. Ultrastructurally they show interdigitating processes containing neurosecretory granules, intermediate filaments, and microtubules. We describe a patient with unusual multiple peripheral neuroectodermal tumors localized to the skin, with benign biologic behavior. The patient related the appearance of new lesions for several years without evidence of visceral dissemination or systemic complications. The histopathologic, immunohistochemical, and ultrastructural findings support the diagnosis of a peripheral neuroectodermal tumor.

Ewingʼs sarcoma and peripheral primitive neuroectodermal tumor

Disease-free survival for patients with small sarcomas of bone has been impressively improved with the use of intensive combination chemotherapy and safe local control with surgery or radiation. The ability of monoclonal antibodies to recognize different antigens has allowed new insights into the histogenesis and has distinguished a neural variant now referred to as malignant peripheral neuroectodermal tumor. Both entities share the translocation t(11;22) (q24;q12) as a constant phenomenon. The breakpoint region has now been cloned, allowing for molecular identification and detection of tumor cells and opening a new era of diagnostic and staging possibilities. Patients with disseminated disease, either at diagnosis or in relapse, have benefitted from megatherapy regimens followed by bone marrow or peripheral stem cell rescue. However, this approach is still under investigation and remains to be standardized.

DNA ploidy and proliferative activity (S-phase) in childhood soft-tissue sarcomas: their value as prognostic indicators

The value of DNA ploidy as a prognostic indicator is well established in many cancers, but recent studies in childhood rhabdomyosarcoma (RMS) have been contradictory. In a retrospective study of 128 cases of soft-tissue sarcoma (STS) diagnosed since 1980, the prognostic value of clinical, histological and flow cytometric parameters was compared, using univariate and multivariate methods. Eighty-one RMSs, 18 extraosseous Ewing's (EOE)/peripheral neuroectodermal tumours (PNETs) and 29 other non-RMS STSs were histologically and clinically reviewed. Five year actuarial survival was 63.4% for all STSs and 69.4% for RMSs. Paraffin-embedded tissue blocks were available for flow cytometry in 90 cases. Of the RMSs, 65.5% were aneuploid [DNA index (DI) > 1.1] compared with 23% of the EOE/PNETs and 31% of non-RMS STSs. Median S-phase was also significantly higher in RMSs (17.0%) than in other STSs (10.8%) (P = 0.0023). Univariate analysis in RMSs showed that stage, ploidy status, S-phase, site and tumour size all had a significant impact on survival. In multivariate analysis of 59 cases of RMS, one clinical and two flow cytometric parameters were independently associated with poor prognosis. These were stage (IV), nonhyperdiploidy (DI < 1.10 and > 1.8) and a high rate of proliferative activity (S-phase > 14.0%). These results confirm that ploidy and S-phase are important new prognostic indicators in rhabdomyosarcoma.

Peripheral neuroectodermal tumor of the chest (Askin tumor) as secondary neoplasm after Hodgkin's disease: A case report

The authors present the case of a 20-year-old woman who developed a peripheral neuroectodermal neoplasm of the thoracopulmonary region (Askin tumor) 7 years after achieving complete remission of stage-IV Hodgkin's disease. The previous treatment had consisted of eight courses of alternating MOPP/ABVD combined with involved-field 20-Gy radiotherapy. The second neoplasm appeared in a nonirradiated area of the chest wall, with erosion of the ribs as shown by sonography and computed tomography. The histological pattern was in accordance with a generic diagnosis of a malignant small cell tumor; the immunostaining positivity of the neoplastic cells for the neuron-specific enolase allowed us to make the diagnosis of a tumor with a neuroectodermal origin. Partial resection of the neoplasm and four courses of chemotherapy including adriamycin, cisplatin, and ifosfamide induced a complete remission, confirmed by surgical restaging. She is alive and well 10 months after the completion of therapy. The clinical, radiological, and microscopic features of this tumor occurring as a secondary neoplasm after Hodgkin's disease are described.