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

Abstract

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 µ/L 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.

Undifferentiated Pleomorphic Sarcoma with Neoplastic Fever: A Retrospective Study

“…Some studies have suggested that cancer can cause fever through several mechanisms, including occult infections, inflammation, vasculitis, localized obstruction due to the tumor, and in situ production of febriferous substances by the tumor. 17,18,24,25 In this study, pathological features were not significantly different between patients with UPS with and without neoplastic fever. The MRI features of patients with UPS with neoplastic fever included intratumoral necrosis and extensive soft tissue edema around the tumor.…”

“…Other studies have also reported that patients with sarcoma with neoplastic fever have this characteristic appearance on MRI. 14 , 18 , 26 Based on these imaging features, we speculated that the neoplastic fever was caused by internal necrosis and surrounding inflammation caused by rapid tumor growth. It is important to note that not all patients with UPS with intratumoral necrosis and peritumoral edema were found to have neoplastic fever.…”

“…These data can help determine whether such patients are likely to respond to immunotherapy. 18 In future research, we will continue to focus on this disease.…”

“…This UPS subtype can develop anywhere in the body, and its incidence rate is even lower than the normal subtypes. [13][14][15][16][17][18] UPS with neoplastic fever has some clinical features which differentiates it from other UPS subtypes. However, no studies have focused on this rare UPS subtype.…”

A novel inflammatory response-related signature predicts the prognosis of cutaneous melanoma and the effect of antitumor drugs

“…Inflammation in TME can accelerate alterations in epigenetic and TME components, jointly promoting tumor development [63]. Hashimoto et al 's study reported a rare case of undifferentiated pleomorphic sarcoma (UPS) in a high C-reactive protein (CRP) senior patient [64]. Considering that both UPS and CM are in a state of hyper-immune infiltration compared to normal tissue and can be classified as "hot tumors, " we speculate that wide margin resection as soon as possible after exclusion of bacteremialike infections may be a new option for the treatment of CM in a severe inflammatory state.…”