Pancreatic involvement by mesenchymal chondrosarcoma harboring the HEY1-NCOA2 gene fusion

Pancreatic metastasis of mesenchymal chondrosarcoma: a surgical case report and review of literature

Introduction

Mesenchymal chondrosarcoma (MC) is a rapidly progressive sarcoma that predominantly impacts the bones. Making up only 3% of chondrosarcomas, about one-third of these tumours develop in extra-skeletal sites.

Case presentation

The authors present a clinical case of a 42-year-old patient who was diagnosed with MC 8 years ago, now admitted to the hospital with a palpable epigastric mass. Clinical and laboratory examinations showed consistent results for MC tumours, with metastasis to the body and tail of the pancreas and invasion of the splenic vein. Surgical resection and systemic screening were performed to ensure that there were no lesions elsewhere. Regular follow-up has found no localized lesions or complications after 15 months.

Clinical discussion

Metastatic extra-skeletal mesenchymal chondrosarcoma of the pancreas is exceptionally rare. To our current understanding, only 14 such cases have been documented in medical literature. The symptoms of pancreatic metastasis are diverse and the radiographic features of metastatic mesenchymal chondrosarcoma are not typically distinct.

Conclusions

Although MC tumours do not frequently occur in sites other than the axial system, a tumour presenting later in a patient with a history of MC should be reviewed to confirm the diagnosis of metastatic MC. Treatment can vary between surgery, radiation therapy and systemic therapy.

A Rare Case Report of Mesenchymal Chondrosarcoma with Pancreatic Metastasis

Background: Mesenchymal chondrosarcoma is a rare but aggressive subtype of sarcoma. The majority of involvement locates in the axial skeleton. Treatment modalities include radical surgery, local radiotherapy, and systemic chemotherapy. However, the long-term survival outcome remains poor. Case presentation: We present the case of a 33-year-old male with a palpable chest wall mass for one year, diagnosed with mesenchymal chondrosarcoma with surgical removal. Later, he had an unusual pancreatic tail tumor as the first presentation of disease metastasis which was proven by surgical resection one year later. Conclusion: Although mesenchymal chondrosarcoma locates mainly in the axial skeletal system, extra-skeletal soft tissue or organ involvement might be seen occasionally. Active surveillance with multidisciplinary team management could significantly prolong survival outcomes.

Genomic profiling identifies genes and pathways dysregulated by HEY1-NCOA2 fusion and shines a light on mesenchymal chondrosarcoma tumorigenesis

Mesenchymal chondrosarcoma is a rare, high‐grade, primitive mesenchymal tumor. It accounts for around 2–10% of all chondrosarcomas and mainly affects adolescents and young adults. We previously described the HEY1–NCOA2 as a recurrent gene fusion in mesenchymal chondrosarcoma, an important breakthrough for characterizing this disease; however, little study had been done to characterize the fusion protein functionally, in large part due to a lack of suitable models for evaluating the impact of HEY1–NCOA2 expression in the appropriate cellular context. We used iPSC‐derived mesenchymal stem cells (iPSC‐MSCs), which can differentiate into chondrocytes, and generated stable transduced iPSC‐MSCs with inducible expression of HEY1–NCOA2 fusion protein, wildtype HEY1 or wildtype NCOA2. We next comprehensively analyzed both the DNA binding properties and transcriptional impact of HEY1–NCOA2 expression by integrating genome‐wide chromatin immunoprecipitation sequencing (ChIP‐seq) and expression profiling (RNA‐seq). We demonstrated that HEY1–NCOA2 fusion protein preferentially binds to promoter regions of canonical HEY1 targets, resulting in transactivation of HEY1 targets, and significantly enhances cell proliferation. Intriguingly, we identified that both PDGFB and PDGFRA were directly targeted and upregulated by HEY1‐NCOA2; and the fusion protein, but not wildtype HEY1 or NCOA2, dramatically increased the level of phospho‐AKT (Ser473). Our findings provide a rationale for exploring PDGF/PI3K/AKT inhibition in treating mesenchymal chondrosarcoma. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Interstitial Deletions Generating Fusion Genes

A fusion gene is the physical juxtaposition of two different genes resulting in a structure consisting of the head of one gene and the tail of the other. Gene fusion is often a primary neoplasia-inducing event in leukemias, lymphomas, solid malignancies as well as benign tumors. Knowledge about fusion genes is crucial not only for our understanding of tumorigenesis, but also for the diagnosis, prognostication, and treatment of cancer. Balanced chromosomal rearrangements, in particular translocations and inversions, are the most frequent genetic events leading to the generation of fusion genes. In the present review, we summarize the existing knowledge on chromosome deletions as a mechanism for fusion gene formation. Such deletions are mostly submicroscopic and, hence, not detected by cytogenetic analyses but by array comparative genome hybridization (aCGH) and/or high throughput sequencing (HTS). They are found across the genome in a variety of neoplasias. As tumors are increasingly analyzed using aCGH and HTS, it is likely that more interstitial deletions giving rise to fusion genes will be found, significantly impacting our understanding and treatment of cancer.

18F-FDG PET/CT Imaging of Pancreatic and Adrenal Metastases in a Patient With Mesenchymal Chondrosarcoma

ABSTRACT

Metastases of mesenchymal chondrosarcoma to either the pancreas or the adrenal glands are rare. We hereby presented the 18F-FDG PET/CT images of a 21-year-old man initially diagnosed with chondrosarcoma of the right 11th rib. His 18F-FDG PET/CT scan after radiotherapy demonstrated 2 hypermetabolic lesions in the right adrenal gland and the pancreas, respectively. These 2 lesions were later confirmed by biopsy to be metastatic mesenchymal chondrosarcoma.

OLIG2 Immunolabeling of Mesenchymal Chondrosarcoma: Report of 14 Cases

Mesenchymal chondrosarcoma (MC) is a rare aggressive mesenchymal sarcoma. Specific markers for the differential diagnosis of MCs remain to be developed. OLIG2 expression has been reported only in neuroepithelial tumors. Recently, OLIG2 expression was found to be involved in the development of NCOA2 fusion-positive alveolar rhabdomyosarcomas. Therefore, we investigated whether OLIG2 expression could be used as a diagnostic marker for MC. We report the clinical pathological and immunohistochemical features of 14 MCs. All tumors showed typical pathological features including biphasic patterns with sheets of primitive round mesenchymal cells and interspersed islands of cartilage. These tumors expressed BCL2, SOX9, and CD99. OLIG2 was robustly expressed in 12/14 of MCs. NCOA2 rearrangement was found in 12 cases. OLIG2 expression was not found in the NCOA2 rearrangement-negative MCs. Notably, OLIG2 expression was not detected in 52 neoplasms (8 Ewing sarcomas, 23 hemangiopericytomas, and 21 chondrosarcomas) that are frequently misdiagnosed as MC. Our findings provide convincing evidence that OLIG2 can serve as a reliable marker in the differential diagnosis of MC and may be a unique neurodevelopmental gene expression signature for the NCOA2 rearranged MCs.

Current Approaches for Personalized Therapy of Soft Tissue Sarcomas

Soft tissue sarcomas (STS) are a highly heterogeneous group of cancers of mesenchymal origin with diverse morphologies and clinical behaviors. While surgical resection is the standard treatment for primary STS, advanced and metastatic STS patients are not eligible for surgery. Systemic treatments, including standard chemotherapy and newer chemical agents, still play the most relevant role in the management of the disease. Discovery of specific genetic alterations in distinct STS subtypes allowed better understanding of mechanisms driving their pathogenesis and treatment optimization. This review focuses on the available targeted drugs or drug combinations based on genetic aberration involved in STS development including chromosomal translocations, oncogenic mutations, gene amplifications, and their perspectives in STS treatment. Furthermore, in this review, we discuss the possible use of chemotherapy sensitivity and resistance assays (CSRA) for the adjustment of treatment for individual patients. In summary, current trends in personalized management of advanced and metastatic STS are based on combination of both genetic testing and CSRA.

Intracranial Mesenchymal Chondrosarcoma Lacking the Typical Histopathological Features Diagnosed by HEY1-NCOA2 Gene Fusion

Intracranial mesenchymal chondrosarcoma (MCS) is a rare neoplasm. The diagnosis of MCS is confirmed by the presence of a biphasic pattern on histological examination, comprising undifferentiated small round cells admixed with islands of well-differentiated hyaline cartilage; however, a differential diagnosis may be challenging in some cases. A 28-year-old woman with a 2-month history of headache was referred to our hospital. Radiologic studies showed an extra-axial lobulated mass composed of calcified and uncalcified areas occupying the left middle fossa. Surgical resection was planned, but her headache suddenly worsened before her planned hospital admission and she was admitted as an emergency. Radiologic studies showed an acute hemorrhage in the uncalcified part of the mass. The mass was resected via the left zygomatic approach after embolization of the feeder vessels. The most likely histopathological diagnosis was MCS. However, the typical bimorphic pattern was not identified in our surgical samples; each undifferentiated area and well-differentiated area was observed separately in different tissue specimens, and no islands of well-differentiated hyaline cartilage were identified within the undifferentiated areas in the same specimen. Molecular assays confirmed the presence of HEY1-NCOA2 fusion. IRF2BP2-CDX1 fusion and IDH1/2 mutations were negative. The final diagnosis of MCS was made based on the presence of HEY1-NCOA2 gene fusion. MCS should be included in the differential diagnosis when radiologic studies show an extra-axial lobulated mass with calcification. Furthermore, molecular demonstration of HEY1-NCOA2 gene fusion may help make a precise diagnosis of MCS, especially in surgical samples lacking the typical histopathological features.

Primary mesenchymal chondrosarcoma of the kidney without HEY1-NCOA2 and IRF2BP2-CDX1 fusion: A case report and review

Mesenchymal chondrosarcoma (MC) of the kidney is rare. To the best of our knowledge, the current report is the first case of a giant extraskeletal MC that arose primarily from the right kidney and mimicked renal cell carcinoma at the locally advanced stage (cT3bN0) with vena cava thrombus and multiple pulmonary arterial tumor emboli. Additionally, the literature on renal EMC is reviewed and the possibilities of oncogenic heterogeneity are discussed. A 64-year-old woman was admitted to Yamagata University Hospital for sudden onset of asymptomatic gross hematuria. CT revealed a 90 mm renal mass without calcification in the right kidney and tumor thrombus extending to the inferior vena cava. Radical nephrectomy with thrombectomy was performed. Lung metastasis was detected 2 months later. The patient received systemic chemotherapy, which was only marginally effective. She died of the malignancy 8 months after surgery. Microscopic examination of the tumor revealed typical histology of MC and a lack of HEY1-NCOA2 and IRF2BP2-CDX1 gene fusions in the tumor tissues. Not all MC patients may exhibit chromosomal alterations in the tumor, suggesting the presence of genetically heterogeneous pathways of MC oncogenesis. Further studies are required to confirm the present findings and reinforce the molecular diagnosis of MC.

Mesenchymal chondrosarcoma metastasising to the pancreas

The mesenchymal chondrosarcoma (MC) is a rare malignant tumour and accounts for less than 3% of primary chondrosarcomas. Mostly MC arises from the craniofacial bones, the ribs, the ilium, the femur and the vertebrae. A 54-year-old man was treated due to an icterus of unknown origin. The medical history of the patient consists of a multimodal treated MC of the thoracic vertebrae. A CT imaging identified a 2×4 cm sized mass of the pancreatic head. Suspecting a pancreatic head carcinoma surgical removal was performed. Histopathological a metastasis of MC was diagnosed. Our patient left the hospital after 17 days and died 23 month after surgery. Metastases of MC to the pancreas are rare. When detecting a mass of the pancreas in patients with a medical history of an MC, a metastasis of these tumour should be taken in consideration.