Small Intestine Gastrointestinal Clear Cell Sarcoma: A Case Report and Review of the Literature.

Gastrointestinal clear cell sarcoma (GICCS)/malignant gastrointestinal neuroectodermal tumor (GNET) is an extremely rare form of cancer with aggressive clinical behavior. It has distinct pathological, immunohistochemical, ultrastructural, and molecular features. Herein, we present the case of a 20-year-old woman with no notable medical history who presented to the outpatient department with complaints of abdominal pain and vomiting. Symptoms had been evolving for 3 months. The physical examination revealed slight abdominal tenderness and melena. Biological investigations revealed iron-deficiency anemia. The upper and lower endoscopies showed no abnormalities. Magnetic resonance enterography revealed small bowel wall thickening of 15 mm × 2 mm. Exploratory laparotomy revealed an ileal mass with mesenteric lymphadenopathy. A wide resection of the mass was then performed. The final pathological report confirmed the diagnosis of small bowel GICCS/GNET. After 11 months of follow-up, the patient presented with mesenteric lymph node metastases.

Malignant gastrointestinal neuroectodermal tumor: A case-based review of literature.

Malignant gastrointestinal (GI) neuroectodermal tumor is an extremely rare entity that was first described by Zambrano et al. in 2003 as "clear cell sarcoma (CCS)-like tumor of the GI tract." It shares some of the histopathological features of CCS but lacks the immunohistochemical (IHC) reactivity for melanocytic markers. Most mesenchymal neoplasms of the GI tract belong to the category of GI stromal tumors and are characterized by the IHC expression of c-KIT. In cases, without detectable KIT receptor expression, several differential diagnoses have to be taken into consideration. In this article, we describe such a case and present a review of all the reported cases till date. We also present the current available knowledge on its pathology and molecular genetics along with the limitations in its diagnosis. Here, we report a case of a 32-year-old man with a tumor of the small bowel composed of polygonal tumor cells arranged in solid nests, alveolar pattern, and pseudopapillary and admixed with numerous osteoclast-like multinucleated giant cells. Immunohistochemically, the tumor cells strongly expressed S-100 protein only. HMB-45, melan-A, CD117, cytokeratin, desmin, smooth muscle actin, and CD-34 were absent. Ki-67 index was 15%. The diagnosis was further confirmed by fluorescence in situ hybridization (FISH) demonstrating the presence of EWSR1 (22q12) translocation. A final diagnosis of malignant gastroneuroectodermal tumor was rendered. The patient is disease-free for 20 months of postsurgery. The diagnosis of this entity should be considered in the presence of S-100-positivity and multinucleated osteoclastic giant cells and the absence of melanocytic differentiation in a tumor arising from GI tract. Further confirmation can be done by performing FISH analysis.

[Malignant gastrointestinal neuroectodermal tumor: A report of 2 cases and a review of the literature]. / Tumor neuroectodérmico maligno del tracto gastrointestinal: Reporte de 2 casos y revisión de la literatura.

Malignant gastrointestinal neuroectodermal tumour (GNET) is an extremely rare neoplasm first described by Zambrano in 2003 as clear cell sarcoma like tumor of the gastrointestinal tract. In contrast to clear cell sarcoma, it has giant osteoclast cells and shows diffuse and intense positivity for S-100 with no immunohistochemical or ultrastructural melanocyte differentiation. We present the first cases of GNET reported in South America, occurring in Peru. Two cases of GNET, one in a female and one in a male, both between 60 and 70 years of age, were referred to our hospital for reevaluation. One underwent further treatment in our centre, but with an unfavourable evolution. Pathologists should be aware of the diagnostic criteria for GNET in order to avoid misdiagnosis due to confusion with other non-epithelial gastrointestinal neoplasms.

A Case Series of Metastatic Malignant Gastrointestinal Neuroectodermal Tumors and Comprehensive Genomic Profiling Analysis of 20 Cases.

Malignant gastrointestinal neuroectodermal tumor (GNET) is an ultra-rare soft tissue sarcoma, therefore often misdiagnosed and has no available standard treatment. Here, we report 3 cases of metastatic GNET with variable clinical courses. Our small case series as well as extensive literature review, further support that GNET is a spectrum of diseases with variable inherent biology and prognosis. Surgical management in the setting of recurrent/metastatic disease may be appropriate for GNET with indolent nature. Response to systemic treatments including chemotherapy and targeted treatments is variable, likely related to heterogenous biology as well. Furthermore, we retrospectively identified 20 additional GNET cases from Foundation Medicine's genomic database and expanded on their clinicopathological and genomic features. Comprehensive genomic profiling (CGP) with DNA and RNA sequencing of this cohort, in the course of clinical care, demonstrated recurrent EWSR1 chromosomal rearrangements and a sparsity of additional recurrent or driver genomic alterations. All cases had low tumor mutational burden (TMB) and were microsatellite stable.

Malignant gastrointestinal neuroectodermal tumor: Cytologic, histologic, immunohistochemical, and molecular pitfalls.

Malignant gastrointestinal neuroectodermal tumor (GNET) is a rare malignant primary gastrointestinal mesenchymal tumor which can be diagnosed via fine-needle aspiration (FNA) cytology. In the context of FNA, the diagnosis requires a cell block and the use of significant resources including immunohistochemical stains and molecular testing. The differential diagnosis of GNET includes clear cell sarcoma (CCS), gastrointestinal stromal tumor (GIST), gastric schwannoma, metastatic melanoma, malignant perivascular epithelioid cell tumor (PEComa) and granular cell tumor, among others. Here we describe a case which was initially diagnosed as malignant granular cell tumor by FNA which was later revised to GNET following the finding of an EWSR1-ATF1 fusion gene rearrangement.

Malignant gastrointestinal neuroectodermal tumor-A case report.

Malignant gastrointestinal neuroectodermal tumor (GNET) is a rare neoplasm with unknown etiology. It was previously referred to as Clear cell sarcoma of gastrointestinal tract. This tumor is characterized by a higher rate of local recurrence and metastasis. Due to its aggressive clinical course, distinguishing this entity from various other mimickers is very essential. Herein, we present a case of malignant GNET in a 33-year-old male patient.

Clear cell sarcoma-like/malignant gastrointestinal neuroectodermal tumor of the tongue: a clinicopathologic and molecular case report.

Malignant gastrointestinal neuroectodermal tumor (M-GNET) and clear cell sarcoma (CCS) of soft tissue represent closely related, extremely rare, malignant mesenchymal neoplasm of uncertain differentiation. Both entities are characterized genetically by the same molecular alterations represented by the presence of EWSR1-ATF1 and, more rarely, EWSR1-CREB1 fusion genes. The latter translocation seems to be more represented in M-GNET that, despite significant morphologic overlap with CCS, tends to lack overt features of melanocytic differentiation. Most M-GNET occur in the lower gastrointestinal tract, whereas occurrence in the upper tract has been reported only exceptionally. The differential diagnosis represents a major challenge, and accurate diagnosis impact significantly on therapeutic planning. We herein report the clinicopathologic features of a molecularly confirmed M-GNET that arose at the base of the tongue and review the pertinent literature.

Fine Needle Aspiration Cytology of Malignant Digestive System Gastrointestinal Neuroectodermal Tumor in a Lymph Node Metastasis from a Previously Diagnosed Liver Primary: A Case Report and Review of Literature.

Malignant gastrointestinal neuroectodermal tumor (GNET) is an extremely rare neoplasm. Immunohistochemically, GNET typically demonstrates neural differentiation but lacks melanocytic differentiation, making it distinct from clear cell sarcoma of the soft tissues (CCS). Herein we report for the first time the cytomorphologic features of lymph node metastasis from presumably liver GNET. A 36-year-old female presented with fevers, night sweats, loss of appetite, and a 20-lbs weight loss. Radiographic imaging showed a 13 cm heterogeneously enhancing mass in the right lobe of the liver and a hypermetabolic 0.9 cm periportal lymph node on positron emission tomography-computed tomography (PET/CT). Initially, a CT-guided liver biopsy was performed followed by right hepatic lobectomy and portal lymphadenectomy. The liver biopsy and resection showed an S100-protein and SOX10 positive malignant neoplasm and genomic profiling of liver biopsy revealed EWSR1-CREB1gene rearrangement. These findings in conjunction with the morphologic and immunohistochemical profile were diagnostic of GNET. Two months later, she presented with recurrent lymphadenopathy in the upper abdomen. Fine needle aspiration of the periportal nodal mass revealed single and clusters of primitive, large to medium-sized neoplastic cells with round to oval nuclei, high nuclear-cytoplasmic ratio, vesicular chromatin, and prominent nucleoli. The tumor cells were S100 protein and SOX10 positive, consistent with metastasis of the patient's recently diagnosed malignant digestive system GNET. Palliative chemotherapy was administered but the patient died a few days later, 4 months from the initial diagnosis. Awareness of this entity and judicial use of ancillary studies including molecular testing are essential for achieving accurate diagnosis.

Oral malignant gastrointestinal neuroectodermal tumour with junctional component mimicking mucosal melanoma.

Malignant gastrointestinal neuroectodermal tumour (GNET) is a recently characterised rare and aggressive tumour that typically arises in association with the small intestine of adults. We present a novel case of this entity and expand the spectrum of its reported morphological features. The patient was a 5-year-old female, the youngest reported patient affected by the condition, and presented with extra-abdominal disease. The histopathological features included the presence of a junctional component of the palatal tumour, which mimicked mucosal melanoma, a feature that has not been previously reported in GNET. Whole genome and RNA sequencing was performed that demonstrated the EWSR1-ATF1 translocation characteristic of GNET. Knowledge of this entity and its features, together with careful morphological assessment supplemented by judicious immunohistochemical and molecular studies should enable the correct diagnosis to be established.

Metachronous renal Ewing sarcoma/primitive neuroectodermal tumour in a survivor of Burkitt lymphoma.

We present a case of a 14-year-old girl who was diagnosed with Burkitt lymphoma in 2014. She was managed with chemotherapy and remained in remission for 3 years. On her surveillance imaging in 2017, a left-sided renal neoplastic mass was incidentally discovered. She underwent nephrectomy and pathology of the resected specimen revealed small cell tumour of the kidney with features favouring renal Ewing sarcoma/primitive neuroectodermal tumour. Molecular genetic analysis by fluorescence in situ hybridisation was performed which showed translocation of 22q12, thereby confirming the diagnosis. This is a rare secondary malignancy and an unusual association. This case highlights the importance and diagnostic dilemmas of rare secondary tumours in patients with such haematological malignancies and discusses its possible pathogenetic aspects.

Review of molecular classification and treatment implications of pediatric brain tumors.

PURPOSE OF REVIEW: Brain tumors are the most common solid tumors and leading cause of cancer-related death in children. The advent of large-scale genomics has resulted in a plethora of profiling studies that have mapped the genetic and epigenetic landscapes of pediatric brain tumors, ringing in a new era of precision diagnostics and targeted therapies. In this review, we highlight the most recent findings, focusing on studies published after 2015, and discuss how new evidence is changing the care of children with brain tumors. RECENT FINDINGS: Genome-wide and epigenome-wide profiling data have revealed distinct tumor entities within, virtually, all pediatric brain tumor groups including medulloblastoma; ependymoma; high-grade and low-grade gliomas; atypical teratoid/rhabdoid tumors; and other embryonal tumors, previously called CNS primitive neuroectodermal tumors. Whenever integrated with clinical information, many molecular alterations emerge as powerful prognostic markers and should thus be used to stratify patients and tailor therapies. SUMMARY: Optimal integration of this newly emerging knowledge in a timely and meaningful way into clinical care is a remarkable task and a matter of active debate. The historical morphology-based classification of tumors is being replaced by a genetic-based classification, and the first generation of molecularly informed clinical trials is underway.

Malignant gastrointestinal neuroectodermal tumor (clear cell sarcoma-like tumor of the gastrointestinal tract) of the small intestine in a 12-year-old boy.

The aim of this paper is a clinical and anatomopathological demonstration of a malignant lesion, a gastrointestinal neuroectodermal tumor (GNET), as an exceedingly rare cause of ileus in the pediatric population. Specifically, we present the case of a 12-year-old boy who showed dramatic weight loss, hypochromic anemia, fever, dehydration, exaggerated granulation of the terminal ileum, and mechanical ileus due to the obstruction by an intramural tumor of the small intestine. A 50cm-long part of the small intestine with pathological stricture was surgically removed, sampled and routinely fixed and stained with hematoxylin and eosin. The additional immunostains that were preformed were: PAS, S-100, HMB-45, NSE, LCA, CK AE1 / AE3, desmin, SMA, vimentin, CD99, NSE, synaptophysin, WT-1, calretinin, and DOG-1. Moreover, fluorescent in situ hybridization (FISH) with the EWSR1 Break Apart FISH Probe was applied. The neoplasm was composed of nests and alveolar patterns of frankly malignant clear cells with immunoreactivity to S-100, vimentin, and CD 99. The FISH technique detected chromosomal breaking at 22q12. The tumor metastasized to both the mesenteric lymph nodes and a number of hepatic segments. With several chemotherapy protocols, repeat laparotomies, and liver thermal ablations, the patient had a 1.5-year-long survival from the moment of diagnosis. The diagnosis of this malignancy requires both histopathological evaluation and molecular analysis, and the follow-up is based on careful clinical imaging of the neoplastic spread in order to apply proper surgical and oncological treatments. In conclusion, the clinical course of GNET was highly aggressive.

Orbital Reconstruction in Neuroectodermal Tumor of the Orbit: Multimodal Treatment Approach.

INTRODUCTION: Primitive neuroectodermal tumors of peripheral origin are very rare, and orbital neuroectodermal tumors are even more uncommon. Only 25 patients with primary orbital involvement in the pediatric age group have been reported. METHODS: In this article, the authors describe their experience in the multimodality treatment approach to treat neuroectodermal tumor of the orbit. The authors also present a male patient 3-year old presenting with a neuroectodermal tumor of the right orbit causing rapidly progressive proptosis. The patient underwent an upper and lateral orbital marginotomy. The entire bone defect was reconstructed with a bone graft, allowing for the reconstruction of the floor and the lateral wall of the middle cranial fossa, the floor of the anterior cranial fossa, the upper and lateral orbital frame, and the right zygomatic bone. Over a period of 16 months, the patient was subjected to chemotherapy. RESULTS: In the postoperative period, a favorable evolution of the disease was observed, with growth in the reconstructed structures, good projection of the orbit and the eyeball, and stable results without tumor recurrence. CONCLUSIONS: The authors present the clinical analysis, surgical management, as well as the chemotherapy treatment established, with follow-ups at 1 and 2 and a half years. This experience shows the effectiveness of multimodality therapy in the treatment of rare tumors of difficult handling.

Brain stereotactic biopsy flow cytometry for central nervous system lymphoma characterization: advantages and pitfalls.

BACKGROUND: Brain stereotactic biopsy (SB) followed by conventional histopathology and immunohistochemistry (IHC) is the gold standard approach for primary central nervous system lymphoma (PCNSL) diagnosis. Flow cytometry (FCM) characterization of fine-needle aspiration cytology and core needle biopsies are increasingly utilized to diagnose lymphomas however, no biological data have been published on FCM characterization of fresh single cell suspension from PCNSL SB. The aim of this study was to establish the feasibility and utility of FCM for the diagnosis and characterization of brain lymphomas from a tissue samples obtained by a single SB disaggregation. METHODS: Twenty-nine patients with a magnetic resonance suggestive for PCNSL entered the study. A median of 6 SB were performed for each patient. A cell suspension generated from manual tissue disaggregation of a single, unfixed, brain SB, was characterized by FCM. The FCM versus standard approach was prospectively compared. RESULTS: FCM and IHC showed an high degree of agreement (89 %) in brain lymphoma identification. By FCM, 16 out of 18 PCNSL were identified within 2 h from biopsy. All were of B cell type, with a heterogeneous CD20 mean fluorescence intensity (MFI), CD10 positive in 3 cases (19 %) with surface Ig light chain restriction documented in 11 cases (69 %). No false positive lymphomas cases were observed. Up to 38 % of the brain leukocyte population consisted of CD8 reactive T cells, in contrast with the CD4 positive lymphocytes of the peripheral blood samples (P < 0.001). By histopathology, 18 B-PCNSL, only one CD10 positive (5 %), 1 primitive neuroectodermal tumor (PNET) and 10 gliomas were diagnosed. A median of 6 days was required for IHC diagnosis. CONCLUSION: Complementary to histopathology FCM can contribute to a better characterization of PCNSL, although necrosis and previous steroid treatment can represent a pitfall of this approach. A single brain SB is a valid source for accurate FCM characterization of both lymphoma and reactive lymphocyte population, routinely applicable for antigen intensity quantification and consistently documenting an active mechanism of reactive CD8 T-lymphocytes migration in brain lymphomas. Moreover, FCM confirmed to be more sensitive than IHC for the identification of selected markers.

Peripheral Primitive Neuroectodermal Tumor of Breast.

Peripheral primitive neuroectodermal tumor (PNET) is a malignant tumor of the young, usually found in bony structures. It is extremely rare to find it in the breast. Only 9 cases have been reported in the medical literature. A35-year lady had a painless lump in upper left outer quadrant of her left breast which appeared as a BIRADS III lesion on mammography. However, biopsy and later surgery was done on clinical grounds. Histopathology and immunohistochemistry diagnosed a PNETtumor. It had recurred 8 years after surgery and required chemotherapy.

New Brain Tumor Entities Emerge from Molecular Classification of CNS-PNETs.

Primitive neuroectodermal tumors of the central nervous system (CNS-PNETs) are highly aggressive, poorly differentiated embryonal tumors occurring predominantly in young children but also affecting adolescents and adults. Herein, we demonstrate that a significant proportion of institutionally diagnosed CNS-PNETs display molecular profiles indistinguishable from those of various other well-defined CNS tumor entities, facilitating diagnosis and appropriate therapy for patients with these tumors. From the remaining fraction of CNS-PNETs, we identify four new CNS tumor entities, each associated with a recurrent genetic alteration and distinct histopathological and clinical features. These new molecular entities, designated "CNS neuroblastoma with FOXR2 activation (CNS NB-FOXR2)," "CNS Ewing sarcoma family tumor with CIC alteration (CNS EFT-CIC)," "CNS high-grade neuroepithelial tumor with MN1 alteration (CNS HGNET-MN1)," and "CNS high-grade neuroepithelial tumor with BCOR alteration (CNS HGNET-BCOR)," will enable meaningful clinical trials and the development of therapeutic strategies for patients affected by poorly differentiated CNS tumors.