Multiple Soft Tissue Sarcomas in a Single Patient: An International Multicentre Review

Synchronous Low-Grade Central Osteosarcoma and Ewing Sarcoma: A Rare Case Report

A 23-year-old female patient presented with radicular back pain, perineal numbness, and urinary retention. The patient was diagnosed with cauda equina syndrome and magnetic resonance imaging (MRI) of the spine revealed an enhancing osseous lumbar lesion causing severe central stenosis. A core needle biopsy of the lumbar spine showed microscopic features compatible with a small round blue cell tumor. CD99 and FLI1 were positive in the tumor cells. Next-generation sequencing demonstrated a EWSR1::FLI1 fusion. Given these findings, the spine lesion was diagnosed as Ewing sarcoma. The patient underwent surgical decompression of L2. On further workup, an MRI revealed an ill-defined enhancing mass of the right distal femur. This area was biopsied, demonstrating a fibro-osseous lesion with osteoblast proliferation containing nuclear atypia, low mitotic activity, and SATB2 positivity, diagnosed as low-grade central osteosarcoma (LGCOS). The patient underwent resection, which showed a classic LGCOS by histomorphology. Although fluorescence in-situ hybridization study for MDM2 gene amplification was negative, the overall findings are most consistent with LGCOS. These neoplasms are considered to be synchronous due to the presentation of each entity within 6 months. Considering the aggregate yearly incidence of Ewing sarcoma (approximately 1 case per 750 000 per year) and LGCOS (approximately 1 case per 10 million per year), the aggregate yearly probability of developing both of these genetically unrelated tumors in a single individual is 1 per 7.5 trillion per year, and it is likely such an event has never happened in the past.

A Rare Coexistence of Hybrid Tumor Low-grade Fibromyxoid Sarcoma/Sclerosing Epithelioid Fibrosarcoma and Hibernoma in the Same Thigh: A Case Report

Introduction

We encountered a unique case of a patient with two distinct tumors coexisting in the same thigh. To the best of our knowledge, this combination of tumors in the same anatomical region has not been previously described in the literature.

Case Report

This case report describes a 38-year-old Caucasian male with a painless mass in his right thigh, which was later diagnosed as a hybrid tumor composed of low-grade fibromyxoid sarcoma and sclerosing epithelioid fibrosarcoma, as well as a second tumor, which was diagnosed as a hibernoma. The patient underwent neoadjuvant chemotherapy and surgical excision, followed by adjuvant radiotherapy and treatment for metastatic recurrence.

Conclusion

The rarity of this case highlights the need for interdisciplinary collaboration and further investigations into the behavior and management of hybrid tumors. This case also underscores the importance of an accurate histological diagnosis aided by immunohistochemistry and molecular analyses.

A case report of 2 distinct primary sarcomas arising in an extremity in rapid succession

A 59-year-old male presented with a primary synovial sarcoma around his knee. Two months after resection, he presented with a new, rapidly-growing mass in the ipsilateral proximal thigh. A biopsy of the new mass demonstrated a pleomorphic liposarcoma, distinct from the prior synovial sarcoma. He underwent neoadjuvant radiation, followed by wide resection. He is now undergoing surveillance for recurrence. While 2 distinct primary sarcomas developing in rapid succession is rare, this case emphasizes the need for a complete work-up, including obtaining a tissue diagnosis for suspected recurrent lesions as this may alter treatment and follow-up recommendations.

Coincidence of Undifferentiated Pleomorphic Sarcoma and Epithelioid Leiomyosarcoma in a Patient; A Case Report

Introduction: Soft tissue sarcoma (STS) is a rare tumor with mesodermal origin. There are more than 100 different types of histology in sarcoma, which present different clinical behaviors. Liposarcoma, leiomyosarcoma, and undifferentiated pleomorphic sarcoma are among the most common pathologies Case Presentation: The patient was a 46-year-old man with 2 masses. The pathology of chest-wall mass (250 × 187 mm) was compatible with undifferentiated pleomorphic sarcoma (UPS). Arm mass (42 × 29 mm) pathology was suggestive of low-grade epithelioid leiomyosarcoma with smooth muscle differentiation. He received two cycles of mesna and doxorubicin and ifosfamide (MAI) regimen chemotherapy due to large and multiple masses, but the tumor size did not change. After consultation with an orthopedic oncosurgeon, wide masses resection was done. Adjuvant chemotherapy with an MAI regimen was continued for a total of 6 courses and radiation with a 60 Gy total dose to the posterior aspect of the chest wall. No recurrence or complications was observed after 4 months of follow-up. Conclusions: Multiple STS is rare; nevertheless, its probability, either synchronous or metachronous, should be considered during patient examine and follow-up. In the case of a secondary lesion, different histology is probable, and the patient should be biopsied and imaged.

Tumour in a tumour: a well-differentiated spindle cell sarcoma within a forearm lipoma

Lipomas are common, benign, soft tissue masses in adults. Sarcomatous change within a giant lipoma is a very rare event. We present a case of a woman presenting with a forearm lipoma that subsequently developed a central, well-differentiated, spindle-cell sarcoma within the lipoma. This case underlines the importance of identifying red flags for referral of soft tissue tumours.