G-CSF Production by Undifferentiated Pleomorphic Sarcoma with Leukemoid Reaction Occurred in the Lower Leg: A Case Report

Undifferentiated Pleomorphic Sarcoma of the Proximal Thigh With Neoplastic Fever and Metachronous Sternal Metastases: A Case Report and Review of the Literature

Undifferentiated pleomorphic sarcoma (UPS) is a rare subtype of undifferentiated soft tissue sarcoma (USTS). UPS is a fast-growing malignant tumor with a high mitotic rate and a high risk of distant metastasis that increases proportionally to tumor size. Obtaining an early diagnosis confers a more favorable prognosis. Neoplastic fever (NF) is the refractory fever subsumed under the category of classic fever of unknown origin (FUO) caused by malignant neoplasms. NF is a paraneoplastic syndrome that rarely occurs in STS. Among UPS tumors, there is an exceptional subtype that causes refractory fever and signs of systemic inflammation. The coexistence of UPS with NF (UPS-NF) represents an unusual event. We present an exceptional case of a 58-year-old male patient with a two-month history of FUO that revealed an atypical clinical presentation of NF generated by a rare STS of the anterior thigh with subsequent sternal metastases. The patient received neoadjuvant chemotherapy and underwent a compartmentectomy with a microscopic residual tumor (R1), followed by postoperative adjuvant radiotherapy with unfavorable results. The patient also presented overlapping paraneoplastic manifestations (NF and areolar hyperpigmentation) that occur concurrently with the onset of metachronous sternal metastases, highlighting the uninvolved lung parenchyma.

Imaging diagnosis and differential diagnosis of extraskeletal osteosarcoma

OBJECTIVE

The aim of this study was to investigate the clinical, imaging and pathological features of extraskeletal osteosarcoma (EOS) and to improve the understanding of this disease and other similar lesions.

METHODS

The data for 11 patients with pathologically confirmed extraosseous osteosarcoma, including tumour site and size and imaging and clinical manifestations, were analysed retrospectively.

RESULTS

Six patients were male (60%), and 5 were female (40%); patient age ranged from 23 to 76 years (average age 47.1 years). Among the 11 patients, 7 had clear calcifications or ossification with different morphologies, and 2 patients showed a massive mature bone tumour. MRI showed a mixed-signal mass with slightly longer T1 and T2 signals in the tumour parenchyma. Enhanced CT and MRI scans showed enhancement in the parenchyma. Ten patients had different degrees of necrosis and cystic degeneration in the mass, 2 of whom were complicated with haemorrhage, and MRI showed "fluid‒fluid level" signs. Of the 11 patients, five patients survived after surgery, and no obvious recurrence or metastasis was found on imaging examination. One patient died of lung metastasis after surgery, and 2 patients with open biopsy died of disease progression. One patient died of respiratory failure 2 months after operation. 2 patients had positive surgical margins, and 1 had lung metastasis 6 months after operation and died 19 months after operation. Another patient had recurrence 2 months after surgery.

CONCLUSION

The diagnosis of EOS requires a combination of clinical, imaging and histological examinations. Cystic degeneration and necrosis; mineralization is common, especially thick and lumpy mineralization. Extended resection is still the first choice for localized lesions. For patients with positive surgical margins or metastases, adjuvant chemoradiotherapy is needed.

Inflammatory Undifferentiated Pleomorphic Sarcoma Mimicking Bacteremia in an Elderly Patient: A Case Report

Undifferentiated pleomorphic sarcoma (UPS) is major type of soft tissue sarcomas. UPS presenting with inflammation is rare, and its pathophysiology remains unclear. Herein, we report a rare case of UPS with prolonged fever. A 91-year-old female complaining of high fever was referred to our hospital because of a high C-reactive protein (CRP) level of 12.51 mg/dL. She had been experiencing intermittent fevers for approximately 10 years. The fever of unknown origin worsened with time and went into remission with repeated antimicrobial therapy. She also had a mass on her central lower back over the sacral region for 6 years, which showed a gradual increase in size. The blood tests showed that the leukocyte count and neutrophils were 6.51 × 10³ /µL and 70.3%, respectively. She had a 10 × 10 cm mass on her buttock that showed 2-[fluorine-18] fluoro-2-deoxy-d-glucose (FDG) accumulation on FDG-positron emission tomography-computed tomography examination (standardized uptake value-max value: 5.4). A blood culture examination was performed to rule out bacteremia, however, no bacteria were identified. We then performed a needle biopsy and confirmed the diagnosis of UPS; subsequently, the patient underwent a wide-margin resection. A few days after the surgery, her CRP, leukocyte, and neutrophil levels decreased to 0.305 mg/dL, 2.83 × 10³/uL, and 50.1%, respectively. This case demonstrated that UPS with inflammation should be treated surgically as soon as possible after ruling out other sources of infection to achieve a favorable prognosis.