Desmin positivity in primitive neuroectodermal tumors of childhood.

In this report, we describe two rosette-forming primitive neuroectodermal tumors that were found to contain desmin by both immunohistochemistry and Western blotting. Electron microscopy on both cases was consistent with primitive neuroectodermal tumors and revealed that the tumor cells contained cytoplasmic bundles of intermediate filaments. In both cases, studies for MyoD1 protein using immunohistochemistry and Western blotting were negative. Thus, the detection of desmin in a pediatric neoplasm does not absolutely exclude the diagnosis of primitive neuroectodermal tumor and should not be considered as prima facie evidence that a small-cell tumor is a rhabdomyosarcoma.     

Malignant gastrointestinal neuroectodermal tumor: clinicopathologic, immunohistochemical, ultrastructural, and molecular analysis of 16 cases with a reappraisal of clear cell sarcoma-like tumors of the gastrointestinal tract

The clinical, histologic, immunophenotypic, ultrastructural, and molecular features of a distinctive gastrointestinal tumor are described. Sixteen patients, 8 women and 8 men aged 17 to 77 years (mean age, 42 y; 63% less than 40 y) presented with abdominal pain, intestinal obstruction, and an abdominal mass. Mean tumor size was 5.2 cm (range, 2.4 to 15.0 cm). The tumors arose in the small bowel (10), stomach (4), and colon (2) and were histologically characterized by a sheet-like or nested population of epithelioid or oval-to-spindle cells with small nucleoli and scattered mitoses. Five cases showed focal clearing of the cytoplasm. Scattered osteoclast-type multinucleated giant cells were present in 8 cases. The tumor cells were positive for S-100 protein, SOX10, and vimentin in 100% of cases, for CD56 in 70%, for synaptophysin in 56%, for NB84 in 50%, for NSE in 45%, and for neurofilament protein in 14% of cases. All cases tested were negative for specific melanocytic, gastrointestinal stromal tumors, epithelial, and myoid markers. Ultrastructural examination of 5 cases showed features of primitive neuroectodermal cells with clear secretory vesicles, dense-core granules, occasional gap junctions, and no evidence of melanogenesis. EWSR1 gene rearrangement was assessed by fluorescence in situ hybridization in 14 cases. Twelve cases (86%) showed split EWSR1 signal consistent with a chromosomal translocation involving EWSR1. One case showed extra intact signals, indicating that the nuclei possessed either extra copies of the EWSR1 gene or chromosome 22 polysomy. Only 1 case showed no involvement of the EWSR1 gene. Six cases demonstrated rearrangement of the partner fusion gene ATF1 (46%), and 3 showed rearrangement of CREB1 (23%); 2 cases lacked rearrangement of either partner gene. Clinical follow-up was available in 12 patients and ranged from 1.5 to 106 months. Six patients died of their tumors (mean survival, 32 mo; 83% less than 24 mo). At last follow-up, 4 patients were alive with regional, lymph node, and liver metastases, and 2 patients were alive with no evidence of disease. The tumor described here is an aggressive form of neuroectodermal tumor that should be separated from other primitive epithelioid and spindle cell tumors of the gastrointestinal tract. The distinctive ultrastructural features and absence of melanocytic differentiation serve to separate them from soft tissue clear cell sarcomas involving the gastrointestinal tract. The designation "malignant gastrointestinal neuroectodermal tumor" is proposed for this tumor type.     

Metastatic primitive neuroectodermal tumor to the kidney

Primitive neuroectodermal tumors of the kidney are rare neoplasms that may mimic renal cell carcinoma, especially in the presence of locally advanced or metastatic disease. Although several cases have been identified as primary renal tumors, this is the first report of metastatic spread of a primitive neuroectodermal tumor to the kidney.     

Peripheral primitive neuroectodermal tumor associated with the anterior mandible: a case report and review of the literature.

Neuroectodermal tumors may arise in many places throughout the body including the diverse tissues of the head and neck. The primitive neuroectodermal tumor is a predominately neural, nonepithelial neoplasm similar to Ewing sarcoma. This article describes an 18-year-old female patient with a highly malignant peripheral primitive neuroectodermal tumor located in the soft tissue anterior to the mandibular symphysis. The clinical and radiographic presentation as well as the histopathology and immunohistochemistry of this rare entity is discussed. A review of the literature with respect to this tumor, as well as the current management of this tumor, is presented.     

Peripheral primitive neuroectodermal tumors of bone. A review of three cases

The recently individualized and still incompletely understood family of peripheral neuroectodermal tumors encompasses several tumor types, of which some have a predilection for bone. Immunocytochemical studies are essential and usually provide the diagnosis. A t(11;22)(q24;q12) translocation is present in over 80% of cases. Ewing's sarcoma is now viewed as an undifferentiated form of peripheral neuroectodermal tumor, and both tumors require management with combination chemotherapy plus radiation therapy and/or surgery. Contradictory data have been reported regarding the comparative prognosis of peripheral neuroectodermal tumor and Ewing's sarcoma, indicating a need for further studies in large numbers of patients. We illustrate these points by three case-reports, two in girls diagnosed with a vertebral primary at five and nine years of age, respectively, and one in a man diagnosed with a pelvic primary at 29 years of age.     

Peripheral primitive neuroectodermal tumor after radiotherapy

A 41-year-old man had a peripheral neuroectodermal tumor develop at the distal third of the fibula 4 years after radiotherapy for relapsed villonodular synovitis. This type of sarcoma usually is classified into the heterogeneic group of small round-cell bone tumors as a subdivision of Ewing's sarcomas. The immuno-staining positivity of the neoplastic cells for the neuron-specific enolase allowed the authors to make the diagnosis of a tumor with neuroectodermal origin. When the histologic study confirmed the diagnosis, the patient was treated with chemotherapy, surgical excision of the tumor, and adjuvant radiotherapy. Radiotherapy is thought to be involved in the genesis of osteogenic sarcomas as it has been shown in several reports, but there is no evidence in the literature of a peripheral neuroectodermal tumor developing after radiotherapy.     

Primitive neuroectodermal tumor with Wilms' tumor. Case report]

Occurrence of embryonal kidney tumors in patients with primitive neuroectodermal tumors, so-called central nervous system-renal neoplasia has been reported. An infant who presented with masses in the right lateral ventricle and the cerebellar vermis is reported. Histological examination showed primitive neuroectodermal tumors. Further investigation revealed tumors in the bilateral kidneys, which were removed subtotally and pathologically shown to be Wilms' tumors. The patient was then treated with anticancer drugs and irradiation. However, he developed lung metastases from the renal tumors and expired. At autopsy, a small tumor was found in the inferior horn of the left lateral ventricle. Histological finding showed a primitive neuroectodermal tumor. Also, bilateral large masses of recurrent Wilms' tumors, multiple metastases to the lungs and peritoneal dissemination were found. There is no evidence that this association is based on the selective neoplastic transformation of embryonal cells of similar histogenetic or cytogenetic origin. Several reports demonstrate the presence of embryonal cells in the nervous tissue which could imply a neuroepithelial origin for Wilms' tumors.     

Applications of monoclonal antibodies in the diagnosis and treatment of primary brain tumors

The development of monoclonal antibodies has resulted in marked expansion in understanding the central nervous system (CNS). This has been especially true in the study of human neuroectodermal tumors where monoclonal antibodies have been used as physiological probes to define and characterize human neuroectodermal tumor-associated antigens. Utilizing monoclonal antibodies, neuroectodermal tumor-associated antigens have been described in four broad categories; biochemically defined markers, shared nervous system-lymphoid cell markers, shared neuroectodermal-oncofetal markers, and putative restricted tumor markers. Preliminary data have demonstrated the ability to localize animal and human tumors in vitro, ex vivo, and in vivo. Early application of monoclonal antibody technology to neuroimmunology and neuro-oncology has resulted in a new awareness of the complex relationships that exist within the CNS. Their specificity and reproducibility may provide the means to qualitatively and quantitatively define the phenotypic heterogeneity of human neuroectodermal tumors. Potentially, monoclonal antibodies, alone or as carriers of radionuclides, drugs, or toxins, may allow successful diagnosis and treatment of human neuroectodermal tumors.     

Primitive neuroectodermal tumor. Ewing's sarcoma

Primitive neuroectodermal tumor is an extraordinarily rare primary tumor in the kidney and can be mistaken for a variety of other round cell tumors. It is important to recognize each of these entities, because each carries unique therapeutic and prognostic implications. However, accurate diagnosis of these tumors is hindered by their significant morphologic overlap and complicated by their rarity. These neplasm are highly aggressive that tend to recurence and to metastatize. Standard therapy combining surgery, chemotherapy, radiation and genetic therapy. We report a case of primitive neuroectodermal tumor of the kidney in a 50 year old female patient.     

Schwannoma with rhabdomyoblastic differentiation: a unique variant of malignant triton tumor

A 54-year-old woman presented with intractable perianal, bilateral buttock, and radiating thigh/calf pain. An MRI scan showed an intradural, contrast-enhancing, ovoid mass in the cauda equina region at L1-L2. At laminectomy, the ovoid mass arose from a nerve root and, intact, was gross totally resected. Histologically, the dominant pattern was that of schwannoma. One year thereafter, the symptoms recurred. An MRI scan demonstrated an irregular, heterogeneously enhancing tumor recurrence. A repeat laminectomy disclosed a large fleshy tumor involving multiple nerve roots. The lesion was subtotally resected and showed pluridirectional differentiation toward embryonal rhabdomyosarcoma, primitive neuroectodermal tumor, and rare malignant epithelial cells. Review of the original tumor disclosed only foci of embryonal rhabdomyosarcoma and primitive neuroectodermal tumor. Based upon available data regarding divergent differentiation in peripheral nerve sheath tumors, this is a unique, previously undescribed tumor demonstrating rhabdomyosarcomatous, primitive neuroectodermal tumor and scant epithelial differentiation in a schwannoma. In essence, it is a variant of malignant Triton tumor because of its origin in a tumor consisting of well-differentiated Schwann cells. It supports the contention that the Schwann cell is the source of a variety of heterologous elements in nerve sheath tumors.     

Pleomorphic xanthoastrocytoma: some observations

The authors describe 3 cases of cerebral pleomorphic xanthoastrocytoma, one of which has an unusual neuroradiological appearance, and review the clinical and prognostic features of the 96 cases reported in the literature. Pleomorphic xanthoastrocytoma is a neuroectodermal tumor that affects young patients, in a superficial or supratentorial site, most frequently at the temporal level. It is difficult to formulate a differential diagnosis with other neuroectodermal tumors or with meningioma on the basis et neuroradiological appearance, as demonstrated by one of the cases reported here. The prognosis of this tumor is very good, regardless of the type of treatment performed, although both relapse and, more rarely, malignant tumor evolution are possible.     

Renal primitive neuroectodermal tumor in childhood with intracardiac extension

Primary primitive neuroectodermal tumors of the kidney are exceptionally rare and usually affect children and young adults. We report the first pediatric case of renal primitive neuroectodermal tumor presenting with tumor extension along the inferior vena cava to the right ventricle. This case highlights that when considering a renal tumor with significant intravascular extension in the pediatric age group, although the most likely diagnosis remains Wilms tumor, other rare entities may also demonstrate similar clinical and imaging features.     

Carotid body tumor and hyperparathyroidism. A case report and review of the literature

Carotid body tumor is an uncommon tumor of the head and neck. The coexistence of this entity with primary hyperparathyroidism is even more unusual, with only four cases having been previously recorded. This report describes a patient with a left inferior parathyroid adenoma and a right carotid body tumor. A common neuroectodermal origin is proposed as an explanation for the simultaneous occurrence of these tumors. The fact that this may represent yet another variable expression of the multiple endocrine neoplasia syndromes emphasizes the importance of careful endocrine screening in patients with carotid body tumors.     

Peripheral primitive neuroectodermal tumors arising in the pancreas: the first case report in Asia and a review of the 14 total reported cases in the world

Objective

To discuss the diagnosis and treatment of peripheral primitive neuroectodermal tumors of the pancreas based on our case and all the cases in the world.

Methods

The first case of peripheral primitive neuroectodermal tumors of the pancreas in Asia was preliminarily reported by our group in 2006. The patient underwent three operations for the primary tumor and recurrences over 41 months prior to the patient’s death in November 2007. All 14 reported cases of pancreatic PNETs in the world were analyzed. The corresponding literatures on its diagnosis and treatment of were reviewed.

Results

A 13 year-old female patient was diagnosed with pancreatic PNETs by the clinical, microscopic, immunohistochemical features, and cytogenetic analysis after the resection of the tumor located in the uncinate process of the pancreas at PUMC Hospital. During the follow-up course, radiotherapy and chemotherapy were given after the first operation. Two additional operations were performed 10 months and 25 months after the first one, respectively, because of tumor recurrence. The patient died 41 months after the initial diagnosis with the recurrence and metastasis that were not suitable for a further surgery. Primitive neuroectodermal tumors of the pancreas are extremely rare. A review of the world’s literature on this tumor identified fourteen cases with a mean survival time of 12 months (ranging from 6 to 50 months). These patients often have no specific clinical symptoms, but most do present with abdominal pain and/or jaundice. The diagnosis is established by small round tumor cells seen on light microscopy, immunohistochemical features of positive P30/32^MIC2 with at least two positive neuronal markers., and cytogenetic analysis showing characteristic translocation of t[11;22][q24;q12]. Since pancreatic PNETs are highly aggressive, early diagnosis, immediate surgical resection and re-resection if possible, early radiotherapy and chemotherapy and close follow-up are required.

Conclusions

Peripheral primitive neuroectodermal tumors can arise in pancreas. The diagnosis and treatment should be made as early as possible, aggressive surgeries for the primary and recurrences may help to improve the prognosis.Key Words: Peripheral primitive neuroectodermal tumors, pancreatic tumor, small round cell tumors, Ewing’s sarcoma     

A primitive neuroectodermal tumor on the face: case report

In 1918, Stout defined the lesion in which small round cells originating from the ulnar nerve formed a rosette as neuroepithelioma. It was claimed that this tumor originated from neuroectodermis and was different from the classical neuroblastoma. The term primitive neuroectodermal tumor (PNET) involves a group of tumors of the soft tissue originating from neural crest and resulting from the brain, spinal cord and branches of the sympathetic nervous system. Extracranial primitive neuroectodermal tumors originate from neural crest cells outside the sympathetic and central nervous system. PNET also has some distinctive histological, immunohistochemical and ultrastructural features. It is usually encountered in children and young adults; most frequently located in thoracopulmonary region (Askin's tumor). The second most commonly involved body part is the extremities. It is very rarely located on the face. PNET is an aggressive tumor. In fact, the disease has a rapid progression, causes local or distant metastases and 50% of the patients die within two years of the presentation. It is treated with aggressive surgery as well as chemotherapy and radiotherapy. In this report, we presented a case of PNET located on the right cheek with multiple distant metastases. Clinicians should be on alert when treating facial tumors, not to skip PNET, which is a very aggressive one.     

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

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

Primitive neuroectodermal tumor in a 57-year-old man

Primitive neuroectodermal tumors are rare cerebral neoplasms previously described only in children and young adults. This report describes such a tumor arising in the left frontal lobe of a 57-year-old man. After surgical resection and radiation therapy to the primary site, the patient developed extensive central nervous system metastases that led to his death. The histopathologic, radiographic, and clinical features of this case suggest that future therapeutic protocols for primitive neuroectodermal tumor should be similar to those for childhood medulloblastoma or neuroblastoma.     

Ischemic colitis: an uncommon manifestation of pheochromocytoma

Pheochromocytoma are rare neuroectodermal tumors, responsible for less than 1 per cent of cases of hypertension. The protean manifestations of pheochromocytomas arise from the effects of catecholamine hypersecretion upon alpha and beta receptors. The lesion may infrequently present with gastrointestinal complaints ranging from constipation and nausea to megacolon and ischemic colitis. Ischemic colitis in association with pheochromocytoma occurs from intense splanchnic vasoconstriction. A case of pheochromocytoma presenting as ischemic colitis is reported.     

Small round cell tumors

A discussion concentrating on the main tumors composing the round cell tumors of bone. Included topics are Ewing's sarcoma, extranodal lymphoma of bone, primitive neuroectodermal tumor of bone and neuroblastoma metastatic to bone.