An unusual association of malignant gastrointestinal neuroectodermal tumor (clear cell sarcoma-like) and Ewing sarcoma

Malignant Gastrointestinal Neuroectodermal Tumor (GNET) Mimicking Small Bowel Lymphoma: A Case Report

A malignant gastrointestinal neuroectodermal tumor (GNET) is a rare entity, characterized as a malignant mesenchymal neoplasm occurring exclusively near the gastrointestinal tract, prone to frequent local recurrence and metastasis. Here, we report a case of a 49-year-old male presented with abdominal pain and weight loss. The patient had a remote history of thymic B-cell lymphoma. An abdominal computed tomography (CT) scan revealed a focal wall thickening of the terminal ileum with mesenteric lymphadenopathy, suggestive of lymphoma. A core needle biopsy of the mesenteric node was inconclusive. A right hemicolectomy was subsequently performed. Histologically, abundant multinucleated osteoclast-like giant cells are present. The tumor cells show diffuse strong positivity for S100 and SOX10. EWSR1-ATF1 gene fusion was identified by fluorescence in situ hybridization (FISH), consistent with a diagnosis of GNET. This case emphasizes a diagnostic challenge of a rare malignancy.

The Malignant Gastrointestinal Neuroectodermal Tumor (GNET): A Distinct Entity and the Challenging Differential Diagnosis with Mesenchymal, Lymphoid, and Melanic Tumors: A Case Report and Brief Review of the Literature

(1) Background: A malignant gastrointestinal neuroectodermal tumor (GNET) is an ultra-rare primary neoplasm with a distinctive histopathological, immunohistochemical, molecular, and ultramicroscopic profile, synonymous terminology with clear cell sarcoma-like tumor of the gastrointestinal tract. This case report aims to describe a case of GNET with challenging mesenchymal, lymphoid, and melanic tumor differential diagnosis. (2) Case presentation: We discuss the case of a 67-year-old male patient who presented with diffuse abdominal pain, intermittent lack of intestinal transit, and frequent episodes of nausea, followed by segmental resection of the jejunum and sigmoid colon. The patient had no relevant medical history. The surgical specimen underwent immunohistochemical staining and morphological evaluation. (3) Results: Histopathological analysis reveals a moderately homogeneous polyhedral-epithelioid and spindle cell neoplastic proliferation with a zonal discohesive pattern and extensive and focal fasciculated architecture. Twenty monoclonal antibodies were used for immunostaining, which allowed GNET to be diagnosed on the basis of the tumoral immune profile, characterized by positive reactivity of S100, SOX10, and CD 56. (4) Conclusions: The poor prognosis of GNET is highlighted in the present study, along with the vital importance of differential diagnosis issues with mesenchymal, lymphoid, and melanic tumors, which make the diagnosis difficult for both pathologists and clinicians.

[Malignant gastrointestinal neuroectodermal tumor: A report of 2 cases and a review of the literature]

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 in the Right Heart: A Report of an Extremely Rare Case Presenting With a Cardiac Mass

Malignant gastrointestinal neuroectodermal tumor (GNET) is an extremely rare soft tissue sarcoma and has been designated as a new entity recently. At present, GNET virtually exclusively occurs in the gastrointestinal tract. Here we report a case of extra-GNET that arose in the right heart. A 62-year-old male complained of chest distress and breathing difficulty while lying down at night for over 1 month at admission. The radiological findings revealed an occupying lesion involving the right atrium and the right ventricle without any abdominal abnormalities. The patient then underwent a surgical resection. Microscopically, neoplastic cells proliferated in the pattern of nests and sheets with fibrous separation. Focal areas with cellular dyscohesion imparted a vague pseudopapillary pattern. These tumor cells were small to medium in size with fine chromatin and predominantly pale eosinophilic cytoplasm. The nuclei were typically round to oval with somewhat irregular contours and contained small nucleoli. The mitotic figures were easily found. Immunohistochemically, the neoplastic cells were positive for S100 and SOX-10 but negative for HMB-45, A103, and CD99. EWSR1-AFTF1 rearrangement was detected by fluorescence in situ hybridization and further confirmed by whole-transcriptome sequence analysis. The patient had pulmonary metastasis 8 months later and soon died of the disease. The overall survival of the patient was 20 months. In summary, we reported an extremely rare case of cardiac GNET, indicating that the location of GNET should not be confined to the GI tract as initially defined. Due to the lack of a specific effective treatment and the occurrence of early metastasis, cardiac GNET conferred a poor prognosis. More clinical and experimental studies are warranted to better manage this disease in the future.

Ewing sarcoma of the jejunum: A case report and literature review

BACKGROUND

Ewing sarcomas (ESs) are highly aggressive malignancy and are predominant in the long bones of extremities of children and young adults with a slight male predilection and rarely presents at extra skeletal locations.

CASE SUMMARY

A 55-year-old woman came to our hospital after finding elevated tumor biomarkers during her physical examination. Her enhanced computed tomography scan showed a jejunal mass. The patient underwent laparoscopic enterectomy. The mass was later diagnosed as ES, evidenced by fluorescence in situ hybridization whereby the GLP ES breakpoint region 1 probe was used, showing that more than 10% of the cells showed a red-green-yellow signal proving the breakpoint rearrangement of the ES breakpoint region 1 gene in chromosome 22.

CONCLUSION

We describe a case of localized ES at the jejunum in China based on the literature.

Clear cell sarcoma like tumor of gastrointestinal tract: Experience of three cases and review of literature

Clear cell sarcoma-like tumor of the gastrointestinal tract (CCSGT) is a rare, aggressive tumor with many histological mimickers. Herein, we have documented our experience of three cases of CCSGT and reviewed the literature. The index cases were identified in male patients in their twenties, one in jejunum and two in the distal colon. Histomorphological examination revealed the characteristic heterogeneous histomorphology with patchy immunohistochemical positivity with S100 protein and negative melanocytic markers. The fluorescence in-situ hybridization test showed translocation of the EWSR1 (22q12) gene in >80% tumor cells. While one of our patients died after 2 years with lung metastasis, the other two patients are still alive on 1.5 years and 3 months follow up, respectively. CCSGT is a rare malignant tumor of the gastrointestinal tract. Although characteristic morphology, use of a judicial panel of immunohistochemical stains, and translocation study for EWSR1 gene can establish the diagnosis, experience in adjuvant therapy is still limited.

Malignant Gastrointestinal Neuroectodermal Tumors: Clinicopathological and Prognostic Features of 96 Patients

Purpose

Gastrointestinal neuroectodermal tumors (GNETs) are uncommon malignant tumors derived from ectodermal primitive neural cells.

Patients and Methods

We retrospectively analyzed 2 GNET cases at our hospital and the remaining 94 cases in the literature to determine clinicopathological prognostic factors.

Results

The patients had a mean age of 36 years and a median tumor size of 4.5 cm. A total of 67.0% of the tumors were located in the small intestine, and 76.4% of the patients presented recurrence or metastasis. There was a significant difference in sex and presence of osteoclast-like cells (P<0.01). Microscopically, most cells were round or short spindle-like in shape, with weak eosinophilic or clear cytoplasm. Neoplastic cells were always arranged in solid sheets, nests, and pseudoalveoli. Immunohistochemistry showed strong, diffuse S100 and SOX10 expression, with a complete absence of HMB45 and Melan-A expression. A total of 72.9% of the cases revealed genetic EWSR1 recombination, including our 2 cases. The median time to death and first metastasis was 61 months and 12 months, respectively. K-M analysis showed a great difference in survival according to lymph node invasion or distant metastasis (M+N), independent lymph node metastasis (N), lower histological grades (G2), and aggressive chemoradiotherapy (P=0.026, P=0.027, P=0.039 and P=0.037). However, independent T, independent M, and postoperative routine adjuvant therapy showed no statistical influence on overall survival or disease-free survival.

Conclusion

GNET is a new entity distinct in its clinical, morphological, immunochemical, and genetic features. Radical excision, close follow-up and adjuvant therapy may be effective for prolonged survival.

Malignant gastrointestinal neuroectodermal tumor, presenting as a second malignancy after gastric adenocarcinoma: a case report and literature review

Malignant gastrointestinal neuroectodermal tumor (GNET), is a rare soft tissue sarcoma. Here we report a case of GNET arising in the intestine of a 33-year-old female, who had been treated for gastric adenocarcinoma with surgery and chemotherapy at the age of 19, in 2001. Since then, she underwent follow-up care annually and kept disease free. Nevertheless, in 2015 she presented with vomiting and was found to have a mass in the small intestine. Surgical excision was performed. Histologically, the tumor was characterized by polygonal cells with clear or eosinophilic cytoplasm, and variably scattered osteoclast-like multinucleated giant cells. Immunohistochemically, the tumor cells showed diffuse and strong expression for S100, but AE1/AE3 cytokeratin, HMB-45 and Melan-A were negative. Genetically, EWSR1 gene rearrangement was detected by fluorescence in situ hybridization (FISH). All these alterations were different from primary gastric adenocarcinoma. Moreover, the tumor gave metastases to ileal mesentery and lung in 1 and 4 years later, respectively. In summary, this is the first report of primary intestinal GNET with multiple metastases in a young woman who had a known history of chemotherapy for gastric adenocarcinoma. In consistence with previous literature, which reported a secondary GNET following chemotherapy for hepatoblastoma, we speculate that the chemotherapy might trigger the rearrangement of EWSR1 and then promote the tumorigenesis of GNET.

Extraskeletal Ewing Sarcoma of the Jejunum: A Case Report

INTRODUCTION

Ewing sarcoma most commonly arises in bones but rarely presents in extraskeletal locations. We report one such case arising from the jejunum.

CASE PRESENTATION

A 67-year-old woman presented with acute-onset, right lower quadrant pain. Computed tomography results showed a large mass within the midjejunum with pneumoperitoneum. Surgical excision was performed, and an extraskeletal Ewing sarcoma of the jejunum was suspected histologically. The diagnosis was confirmed with fluorescence in situ hybridization studies.

CONCLUSION

This case emphasizes the importance of recognizing this rare presentation in the small intestine to broaden the differential diagnosis of adult intraabdominal tumors.

Primary malignant gastrointestinal neuroectodermal tumor occurring in the ileum with intra-abdominal granulomatous nodules: A case report and review of the literature

Malignant gastrointestinal neuroectodermal tumors (GNETs) are rare aggressive malignant neoplasms that exclusively occur within the wall of the gastrointestinal tract. The GNET was first described as an ‘osteoclast-rich tumor of the gastrointestinal tract with features resembling clear cell sarcoma (CCS) of soft parts’ in 2003. Although the GNET shares certain histological features with CCS, it is characterized by a lack of melanocytic differentiation and the presence of non-tumoral osteoclast-like giant cells (OLGCs). The present study reports a case of a GNET of the ileum with intra-abdominal granulomatous nodules, an uncommon accompanying finding, and summarizes the current literature. A 30-year-old woman presented with the symptoms of intestinal obstruction, and a mass was found within the ileum wall. Multiple grey-white nodules were found adhering to the omentum and serosa of the ileum. Histologically, the tumor was located in the muscularis propria and infiltrated the mucosa and the serosa. Tumor cells presented with oval or polygonal nuclei and prominent nucleoli, and were predominantly arranged in nested and pseudopapillary patterns, with the presence of cluster of differentiation (CD)68-positive, scattered OLGC. Immunohistochemically, it was determined that the tumor cells expressed Vimentin, CD56, S-100 and transcription factor SOX-10, while being negative for pan-cytokeratin, cytokeratin (CK)7, CK20, synaptophysin, chromogranin-A, CD117, anoctamin-1, CD34, human melanoma black-45, Melan-A, smooth muscle actin, CD3 and CD20 expression. Ewing sarcoma breakpoint region 1 gene rearrangement was identified by fluorescence in situ hybridization analysis. Ultrastructurally, no typical melanosomes were identified. In addition, the intra-abdominal grey-white nodules were microscopically identified as chronic granulomatous inflammation. The patient received four cycles of adjuvant chemotherapy following routine tumor resection. Due to its rarity and histological similarity with other neoplasms, unfamiliarity with the features of GNETs by surgical pathologists can easily lead to a misdiagnosis. Therefore, comprehensive assessments, including morphology and ancillary studies, are required for an accurate diagnosis of GNET.

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.

Clear cell sarcoma of the gastrointestinal tract and malignant gastrointestinal neuroectodermal tumour: distinct or related entities? A review

Clear cell sarcoma is an uncommon sarcoma which rarely occurs as a primary tumour in the gastrointestinal tract (CCS-GIT). It shares common molecular genetic abnormalities with the more recently described entity, malignant gastrointestinal neuroectodermal tumour (GNET) but is distinguished by its morphological and immunohistochemical findings. The exact nosological relationship between these tumours continues to be debated. In this review, we present two cases of these rare neoplasms from our files and perform a statistical comparison of all published cases to determine if significant differences exist in their clinicopathological features and biological behaviour. Thirteen cases of CCS-GIT and 58 of GNET were included. CCS-GIT occurred more commonly in males (84.6% vs 46.6%, p = 0.01) and in an older age group (median 57 vs 33 years, p < 0.01). There was no significant difference in their location in the gastrointestinal tract, median tumour size and proportion of cases with an EWSR1-ATF1 vs EWSR1-CREB1 fusion. Median survival for CCS-GIT was 13.5 months and for GNET, 9.5 months (p = 0.78). There was no significant difference in the Kaplan-Meier survival curves for either time to first metastasis (p = 0.88) or overall survival (p = 0.18), including after controlling for tumour size using regression models. Our analysis confirms that aside from morphological variations between these tumours, they also exhibit epidemiological and clinical differences. Despite the prevalent perception that GNET is associated with a more aggressive clinical course, our findings indicate that there is no significant difference in their biological behaviour, although both clearly share a bleak prognosis. Further experience is awaited to determine optimal treatment strategies and whether CCS-GIT and GNET would differ in their response to various therapies.

Primary Ewing's sarcoma/primitive neuroectodermal tumor of the ileum: case report of a 16-year-old Chinese female and literature review

Background

Ewing’s sarcoma (ES) and primitive neuroectodermal tumors (PNET) are closely related tumors. Although soft tissue ES/PNET are common in clinical practice, they are rare in the small intestine. Because of the absence of characteristic clinical symptoms, they are easily misdiagnosed as other benign or malignant diseases.

Case presentation

Here, we present the case of a 16-year-old female who complained of anemia and interval hematochezia. Her serum test results showed only a slight elevation of CA-125 and a low level of hemoglobin. Computer tomography and magnetic resonance imaging revealed a cystic and solid mass in the lower abdominal quadrant and pelvic region, which prompted suspicion of a malignant gastrointestinal stromal tumor of the small intestine. After resection, the tumor’s histology and immunohistochemistry (positive for CD99, vimentin and synaptophysin) results suggested ES/PNET. Fluorescent in situ hybridization tests proved the breakpoint rearrangement of the EWSR1 gene in chr 22.Ultrastructural analysis revealed neurosecretory and glycogen granules in the tumor cell cytoplasm.

Conclusions

Together, these data supported the diagnosis of a rare case of localized ES/PNET in the small intestine without adjuvant chemo- or radiotherapy. To our knowledge, this is the first report from China of a primary small bowel ES/PNET in the English-language literature. In addition, on the basis of findings from previous publications and the current case, the optimal treatment for localized gastrointestinal ES/PNET is discussed.

Malignant gastrointestinal neuroectodermal tumor: a case report and review of the literature

BACKGROUND

Malignant gastrointestinal neuroectodermal tumor (GNET) is an extremely rare entity that was first described by Zambrano et al. in 2003 as "Clear cell sarcoma-like tumor of the gastrointestinal tract". It shares some of the histological features of clear cell sarcoma (CCS) but lacks the immunohistochemical reactivity for melanocytic markers. We report a case of GNET that was initially misdiagnosed as gastrointestinal stromal tumor (GIST). Recognizing this entity is important to avoid misdiagnosis.

CASE PRESENTATION

A case of an 18-year-old male presented with a small intestinal tumor. Histologically it was characterized by polygonal cells arranged in pseudoalveolar pattern and situated in the muscularis propria. Scattered osteoclast-like multinucleated giant cells were also noted. The neoplastic cells were positive for S-100 protein and negative for HMB-45, Melan A, smooth muscle actin, desmin and CD117. EWSR1 gene rearrangement was detected by fluorescence in situ hybridization (FISH) analysis. The patient returned with recurrence after 36 months' management by surgical resection and died one year later.

CONCLUSIONS

GNET can be mistaken histologically for other non-epithelial gastrointestinal tumors. Awareness of its existence and diagnostic criteria by the pathologist is necessary to avoid misdiagnosis, particularly as GIST, CCS or malignant peripheral nerve sheath tumor (MPNST).