Extraskeletal mesenchymal chondrosarcoma arising from soft tissues: A rare case report.

BACKGROUND: Chondrosarcomas are an exceedingly rare form of cancer, impacting only a few individuals per million. Among chondrosarcomas, a small fraction belongs to the mesenchymal sub-type. Furthermore, only one-third of mesenchymal chondrosarcomas manifest in extraskeletal locations. CASE: A 38-year-old woman was referred by a midwife after experiencing pain in the right upper quadrant of her right breast for 2 months. The mass had been palpable for 1 week before the initial assessment. According to radiological evaluations, the tumor is outside breast tissue and not connected to the bones. Hence, a biopsy of the mass is done. The biphasic morphology of the tumor during pathological evaluation, in addition to immunohistochemistry testing, confirms the diagnosis of extraskeletal mesenchymal chondrosarcoma (EMCS). Finally, the mass was surgically removed, and 6 months of chemotherapy were administered to the patient. CONCLUSION: Given the tumor's rarity and the lack of established guidelines, diagnosing EMCS can be challenging and prone to errors. As such, meticulous sampling, along with precise pathological and imaging investigations, is imperative to accurately establish the diagnosis of these tumors.

Repeated robotic pancreatectomy for recurrent pancreatic metastasis of mesenchymal chondrosarcoma: A case report.

Mesenchymal chondrosarcoma is a rare subset of sarcomas accounting for 3%-10% of all cases of chondrosarcomas. Radical resection is the only curative strategy, even in patients with metastatic tumors. However, data regarding treatment strategies remain limited owing to the small number of cases. Herein, we report a patient who underwent repeated robotic pancreatectomy for recurrent pancreatic metastasis originating from extraskeletal mesenchymal chondrosarcoma of the pelvis. First, robotic pancreaticoduodenectomy with a reconstruction of pancreaticogastrostomy was performed for synchronous pancreatic metastasis 5 months after the primary resection of mesenchymal chondrosarcoma. Ten months after robotic pancreaticoduodenectomy, tumor recurrence was observed at the tail end of the pancreas, which was removed by reperforming robotic distal pancreatectomy. Given the precise tissue manipulation that can be achieved with robotic articulated forceps, the peripheral splenic artery and pancreas were easily isolated and divided in close proximity to the tumor. The central part of the pancreas was preserved. Robotic surgery allowed safe and effective resection of the reconstructed remnant pancreas. The patient survived for 28 months after primary tumor resection. Repeated pancreatectomy with minimally invasive techniques is a feasible and curative treatment for metastatic mesenchymal chondrosarcoma.

Mesenchymal chondrosarcoma: An Australian multi-centre cohort study.

BACKGROUND: Mesenchymal chondrosarcoma (MCS) is an ultra-rare sarcoma that follows a more aggressive course than conventional chondrosarcoma. This study evaluates prognostic factors, treatments (surgery, chemotherapy, and radiation), and outcomes in an Australian setting. METHODS: We collected demographics, clinicopathological variables, treatment characteristics, and survival status from patients with MCS registered on the national ACCORD sarcoma database. Outcomes include overall survival (OS) and progression-free survival (PFS). RESULTS: We identified 22 patients with MCS between 2001-2022. Median age was 28 (range 10-59) years, 19 (86%) had localised disease at diagnosis of whom 16 had surgery (84%), 11 received radiation (58%), and 10 chemotherapy (53%). Ten (52%) developed recurrence and/or metastases on follow-up and three patients with initial metastatic disease received surgery, radiation, and chemotherapy. At a median follow-up of 50.9  (range 0.4-210) months nine patients had died. The median OS was 104.1 months (95% CI 25.8-182.3). There was improved OS for patients with localised disease who had surgical resection of the primary (p = 0.003) and those with ECOG 0-1 compared to 2-3 (p = 0.023) on univariate analysis. CONCLUSIONS: This study demonstrates contemporary Australian treatment patterns of MCS. The role of chemotherapy for localised disease remains uncertain. Understanding treatment patterns and outcomes help support treatment decisions and design of trials for novel therapeutic strategies.

Novel low-grade renal spindle cell neoplasm with HEY1::NCOA2 fusion that is distinct from mesenchymal chondrosarcoma.

HEY1-NCOA2 fusion is most described in mesenchymal chondrosarcoma. This is the first case report of a primary renal spindle cell neoplasm of uncertain malignant potential with a HEY1::NCOA2 fusion identified by Fusionplex RNA-sequencing that is histologically distinct from mesenchymal chondrosarcoma. The neoplasm was identified in a 33-year-old woman without significant past medical history who underwent partial nephrectomy for an incidentally discovered renal mass. The histologic features of the mass included spindle cells with variable cellularity and monotonous bland cytology forming vague fascicles and storiform architecture within a myxoedematous and collagenous stroma with areas of calcification. The morphologic and immunophenotypic features were not specific for any entity but were most similar to low-grade fibromyxoid sarcoma. To date, the patient has not had recurrence, and the malignant potential of the neoplasm is uncertain.

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.

Extraskeletal Mesenchymal Chondrosarcoma of Central Nervous System - A Rare but Aggressive Tumor: Analysis of Five Cases.

Background: Extraskeletal mesenchymal chondrosarcoma (MCS) of the central nervous system (CNS) is extremely rare. Herein, we present the clinicopathological features of five CNS extraskeletal MCS. Material and Methods: Over the past 10 years, five cases of CNS MCS have been retrieved from in the archives of histopathology department. All biopsies were stained with vimentin, S-100, CD99, desmin, GFAP, INI1, WT1, STAT6, and EMA. Results: There were four males and one female patient in the age group of 1.5-35 years. The clinical and radiological impression was meningioma in three cases, glomus jugulare and primitive neuroectodermal tumor in one case each. All showed classic biphasic morphology, areas of undifferentiated small blue round cells sharply demarcated from the island of cartilage. Three patients experienced multiple recurrences and died subsequently. Conclusion: Extraskeletal MCS of CNS is rare and favors children and young adults. They show aggressive behavior and tend to recur despite surgery and radiotherapy.

Bilateral renal metastases from extraskeletal mesenchymal chondrosarcoma of thigh.

Mesenchymal chondrosarcoma (MC) is a rare cartilaginous tumour that occurs in the extraskeletal locations in about one-third of cases. It is aggressive in behaviour and may involve the lower extremities, central nervous system or spine. Mesenchymal tumours are known for distant metastasis; however, metastasis to bilateral kidneys after treatment has not been reported earlier. We present a case of a soft-tissue intramuscular MC of the thigh in a 38-year-old patient which had been surgically excised after neoadjuvant chemotherapy. The patient presented with bilateral dense calcified renal masses after 6 years, which were cytologically proven as MC metastases. In the evaluation of bilateral calcified renal masses in patients with a history of MC, metastasis should be considered.

Mesenchymal chondrosarcoma of the chest wall in an adolescent patient: A case report and brief review of the literature.

BACKGROUND: Mesenchymal chondrosarcoma is a rare and aggressive bone tumor with few reports of primary tumor in the chest wall. CASE: We report a case of a 17-year-old male presenting with back pain and a posterior mediastinal mass. Imaging demonstrated what was thought to be a benign chondral tumor. The patient underwent resection which confirmed extraskeletal mesenchymal chondrosarcoma. The patient declined proposed adjuvant chemotherapy and underwent multiple resections for rapid local reoccurrence. He ultimately elected for hospice care. CONCLUSION: The case highlights the importance of close disease monitoring and exploration of treatment options, given lack of established guidelines and consistent tumor features.

[Extraskeletal mesenchymal chondrosarcoma in central nerve system: a clinicopathological analysis].

Objective: To investigate the clinicopathological features, immunophenotype, molecular genetics and prognosis of extraskeletal mesenchymal chondrosarcoma in central nerve system (CNS). Methods: The clinicopathological findings, immunohistochemistry and genetic analysis of four cases of extraskeletal mesenchymal chondrosarcoma in Xuanwu Hospital between 2014 and 2019 were reviewed and followed up. Results: The ages of patients ranged from 20-35 years. Three patients had intracranial lesions and one had intradural tumor. The characteristic histologic features were undifferentiated small cells together with scattered islands of hyaline cartilage. There was hemangiopericytoma-like pattern with calcification and ossification. The tumor cells were positive for VIM and SOX9; and the small cells were positive for CD99, NSE and NKX3.1. The cells in chondroid matrix were positive for S-100. All tumor cells were negative for markers including CKpan, EMA and desmin. At molecular analysis, HEY1-NCOA2 fusion transcripts were identified in three patients. The fusion points were between exon 4 of HEY1 and exon 13 of NCOA2. Follow-up information was obtained in two patients, and both were free from recurrence or metastasis at 8 and 20 months. Conclusions: Extraskeletal mesenchymaI chondrosarcoma is a rare CNS disease with poor prognosis. In addition to SOX9, NKX3.1 can be another useful antibody for the differential diagnosis. The combination of pathological characteristics, immunophenotype and genetic profile of tumor is essential for diagnosis.

[Mesenchymal chondrosarcoma in central nervous system: a clinicopathological analysis].

Objective: To investigate the clinicopathological features of central nervous system (CNS) mesenchymal chondrosarcoma (MCS). Methods: Nine cases of CNS MCS were collected at the First Affiliated Hospital of Fujian Medical University from September 2010 to September 2020. The clinical,imaging,histopathological and immunohistochemical features were reviewed. NCOA2 gene rearrangement was evaluated by fluorescence in situ hybridization (FISH). Results: There were three male and six female patients, with age range of 1 to 59 years (median 31 years). Six cases were intracranial and three cases were intraspinal, and the tumors showed dural attachment. They were often diagnosed as meningioma basing on preoperative imaging. Microscopically, the tumors showed a characteristic biphasic histologic pattern composed of undifferentiated mesenchymal small cells and well-differentiated hyaline cartilage islands. The small cells area were positive for SOX9 (9/9), CD99 (8/9), and without BRG1 and INI1 deletion. The cartilaginous component expressed SOX9 (9/9) and S-100 protein (8/9). NCOA2 gene break apart signal was identified in five cases (5/5). Eight patients were followed up for 4-124 months. Three patients (3/8) had recurrences within one year and two patients died of the tumor. Conclusions: CNS MCS is an extremely rare malignant neoplasm with a propensity to dural involvement. Preoperative imaging has low diagnostic accuracy. CNS MCS should be differentiated from other CNS small round cell tumors and chondrosarcoma. FISH detection of NCOA2 gene rearrangement will assist the diagnosis of MCS.

Intravascular Mesenchymal Chondrosarcoma of the Femoral Vein: A Case Report.

CASE: A 30-year-old man presented with progressive lower right extremity pain and swelling, initially diagnosed as a deep venous thrombosis. He returned 18 months later after 2 episodes of gross hemoptysis, with chest computed tomography angiography findings concerning for tumor thrombus in the left pulmonary artery. Subsequent advanced imaging showed a lesion arising from his right femoral vein, which open biopsy revealed to be a primary intravascular mesenchymal chondrosarcoma. He underwent medical therapy, with improvement of pain and swelling and successful return to work. CONCLUSION: Mesenchymal chondrosarcoma is a rare pathology, and its intravascular origin makes this case extraordinarily uncommon.

Mesenchymal Chondrosarcoma in the Maxilla: A Case Report and Literature Review.

Mesenchymal chondrosarcoma is a rare high-grade variant of chondrosarcoma distinguished by its aggressive nature. Molecular studies aid in establishing the diagnosis. We present a case report of mesenchymal chondrosarcoma in the maxilla of a 39-year-old male patient and a literature review of 42 gnathic cases of mesenchymal chondrosarcoma with a discussion of clinical, imaging, microscopic, immunohistochemical, and molecular features.

Heavily calcified parapharyngeal space mesenchymal chondrosarcoma: Imaging and pathological findings and a review of the literature.

Parapharyngeal space (PPS) masses are relatively rare lesions of the head and neck, and account for 0.5-1.5% of head and neck lesions. The most common lesion to occur in the PPS is a benign salivary neoplasm, typically pleomorphic adenoma either from the deep parotid or from ectopic parotid tissue rests within the PPS. A calcified or ossified mass in this location is exceedingly rare, but a calcified variant of pleomorphic adenoma has been reported. In this study, we present a patient with a heavily calcified PPS mesenchymal chondrosarcoma with an unusual presentation. We discuss the imaging and pathologic findings followed by a review of the current literature.

Intracranial extra-axial mesenchymal chondrosarcoma in a 16-month-old patient with a literature review of pediatric patients.

Mesenchymal chondrosarcoma is a rare high-grade malignant subtype of chondrosarcoma that is characterized by undifferentiated, round, or spindled mesenchymal cells, interspersed with islands of hyaline cartilage. We report a primary intracranial extra-axial mesenchymal chondrosarcoma in a 16-month-old patient with a review of the literature focusing on intracranial extra-axial MCs with or without skull involvement in pediatric patients, including differential diagnosis. The patient was admitted with a swelling in the right temporooccipital region. There was intracranial extra-dural extension of the mass, which abuts the neural parenchyma without any invasion. A complete tumor resection was performed. Pathological diagnosis was mesenchymal chondrosarcoma. The patient was free of symptoms after surgery.

Mesenchymal chondrosarcoma of the orbit masquerading as a hemophilic pseudotumor.

An 11-year-old boy presented with a lesion of the right orbit that was thought to be a hemophilic pseudotumor. Excisional biopsy revealed an unexpected diagnosis of mesenchymal chondrosarcoma. Both mesenchymal chondrosarcoma and hemophilic pseudotumor of the orbit are exceedingly rare. To the best of our knowledge, this is the first reported case of orbital mesenchymal chondrosarcoma masquerading as hemophilic pseudotumor.

Primary Spinal Intradural Extramedullary Mesenchymal Chondrosarcoma.

BACKGROUND: Among chondrosarcomas arising from bones and soft tissues, mesenchymal chondrosarcoma (MCS), especially primary spinal intradural extramedullary MCS, is extremely rare, and only 18 cases have been reported to date. We report an adult case of this rare condition mimicking meningioma. CASE DESCRIPTION: A 42-year-old woman presented with paraplegia and sensory disturbance associated with right-sided Brown-Séquard syndrome following back pain. Magnetic resonance imaging showed an intradural mass in the right dorsal spinal canal with homogeneous enhancement and dural tail sign at the T8 level. Computed tomography demonstrated a calcified portion in the mass. Following T7-8 laminectomies, an intradural extramedullary tumor was completely removed after detaching the tumor from the dura mater. The histopathologic diagnosis was MCS, and positron emission tomography showed no metastatic lesions at other sites. The patient did not receive adjuvant therapy, and magnetic resonance imaging revealed no evidence of recurrence during 2-year follow-up. CONCLUSIONS: Primary spinal intradural extramedullary MCS has been reported to have a better prognosis than MCS occurring in other regions. In a case with early complete surgical resection, adjuvant therapy should be considered at the time of recurrence.

Paediatric High-Grade Intracranial Mesenchymal Chondrosarcoma: A Case Report with 6 Years of Follow-Up without Recurrence.

INTRODUCTION: Intracranial mesenchymal chondrosarcoma (MSC) is an extremely rare tumour that constitutes only 0.015% of all central nervous system tumours. These tumours usually originate from skull base synchondrosis and are often observed in young adults during their second and third decades of life. Despite the absence of a consensus regarding adjuvant radiotherapy, radical excision remains crucial for the prognosis of MSC. CASE PRESENTATION: We herein present the case of a young male patient with intracranial MSC, a malignant tumour, for which no consensus regarding its treatment has yet been established. The patient underwent radical excision followed by adjuvant radiotherapy. Histological analysis revealed a poorly differentiated tumour containing necrotic areas. Notably, no signs of recurrence had been observed after 6 years. CONCLUSION: The absence of recurrence over a long follow-up duration suggests the importance of radical excision and adjuvant radiotherapy.

Metastasectomy of left atrial mesenchymal chondrosarcoma.

Metastasis of chondrosarcoma of skeletal origin to the heart is uncommonly reported in the literature, with the majority of cases involving right atrial metastases. Surgical resection remains the mainstay of treatment, and the literature has shown improved median survival with this form of therapy, possibly by reducing thromboembolic risk in this patient population. We report the case of a patient with metastatic mesenchymal chondrosarcoma of the left atrium who underwent resection, following a lack of response to anticoagulation therapy. This is the first report of surgical resection of left atrial metastatic disease prior to the onset of thromboembolic sequelae.