Malignant peritoneal mesothelioma (MPM) is a rare and invasive tumor, and some patients will develop paraneoplastic syndrome (PS) during the course of the disease. This review summarizes PS associated with MPM, focusing on the clinical characteristics and treatment progress in hematological, endocrine, rheumatic, neurological, urinary, and other systems to decrease missed diagnosis and misdiagnosis, help early diagnosis and prompt treatment, and provide guidance for the clinical decision-making of this kind of patients.

BACKGROUND: Malignant peritoneal mesothelioma (MPM) is a rare and highly aggressive tumor. Its clinical manifestations are diverse, and the symptoms are not specific. Some patients will develop paraneoplastic syndrome (PS) during the disease course. This study aims to analyze the risk factors of PS in patients with MPM and their impacts on prognosis.
METHODS: The clinical data of MPM patients who underwent cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) at our center from June 2015 to May 2023 were retrospectively analyzed. MPM patients were divided into PS group and non-PS group according to the diagnostic criteria. Univariate and multivariate analyses were performed to explore the risk factors of PS in MPM patients, and to analyze the impact of PS on prognosis.
RESULTS: There were 146 MPM patients in this study, including 60 patients (41.1%) with PS and 86 patients (58.9%) without PS. The highest incidence of PS was thrombocytosis (33.6%), followed by neoplastic fever (9.6%). Univariate analysis revealed 8 factors (P < 0.05) with statistically significant differences between the two groups: prior surgical scores, targeted therapy history, Karnofsky performance status score, preoperative carbohydrate antigen (CA) 125 level, vascular tumor embolus, peritoneal cancer index, completeness of cytoreduction (CC) score and intraoperative ascites. Multivariate analysis identified 3 independent factors associated with PS: preoperative CA 125 level, vascular tumor embolus, and CC score. Survival analysis demonstrated that MPM patients with PS had worse prognosis, although PS was not an independent prognostic factor.
CONCLUSIONS: PS is not rare in patients with MPM, and is independently associated with preoperative CA 125 level, vascular tumor embolus and CC score. PS often indicates advanced disease and poor prognosis.

Upper tract urothelial carcinoma (UTUC) is a relatively rare malignant neoplasm of the urinary system. Due to its highly aggressiveness, the tumor has already undergone invasive growth when most UTUC patients are diagnosed. In addition, the most common cause of fever in cancer patients is infection, and cancer patients with neoplastic fever are relatively rare. We reported a 58-year-old man with invasive high-grade UTUC accompanied by hyperthermia.

Malignant gastrointestinal neuroectodermal tumors (GNETs) are mesenchymal tumors that typically arise in the digestive tract and harbor EWSR1::ATF1 or EWSR1::CREB1 fusions. We report a case of primary retroperitoneal GNET in a 38-year-old woman who presented with a month-long fever with increased serum IL-6 level. A right retroperitoneal mass of 7 cm consisting of diffuse sheets of small cells with a high nuclear-to-cytoplasmic ratio and scattered osteoclast-like multinucleated giant cells was confirmed apart from the digestive tract. Peripheral lymphoid cuff and focal pseudoangiomatous spaces were present, reminiscent of angiomatoid fibrous histiocytoma. The tumor cells were positive for S100 protein and SOX10 and negative for melanocytic markers. Fluorescent in situ hybridization revealed EWSR1 and CREM gene rearrangements, consistent with EWSR1::CREM fusion, which has never been reported in GNET. The patient lives with recurrent lesions for 8 months. This case was associated with several unusual features and contributes to the evolving GNET concept.

OBJECTIVE: Primary breast sarcomas are extraordinary rare, in particular undifferentiated pleomorphic sarcoma (UPS). UPS with neoplastic fever (UPS-NF) of the breast has not been reported yet. Here, we present an extended UPS-NF of the breast including its comprehensive molecular workup.
METHODS: A 58-year-old female presented with general malaise, fever spikes, weight loss, and a massively swollen left breast. C-reactive protein and blood leucocytes were significantly increased. However, repeated blood cultures and smears were all sterile. Histopathology of the abscess-forming tumor revealed an undifferentiated malignancy with numerous of tumor giant cells as well as spindle-shaped cells with nuclear pleomorphism and hyperchromasia. Immunohistochemistry demonstrated partial, patchy desmin staining and weak heterogonous neuron-specific enolase immunoreactivity of tumor cells, but a focal staining for Melan-A.
RESULTS: Neither common melanoma driver mutations nor an ultraviolet mutational signature was detected by whole genome sequencing. Using FISH and RT-PCR we also excluded translocations characteristic for clear cell sarcoma. Thus, the diagnosis of inflammatory UPS-NF of the breast was considered highly probable. Despite a complete mastectomy, the tumor recurred after only three months. This recurrence was treated with a combination of ipilimumab and nivolumab based on the primary tumor\'s TPS score for PD-L1 of 30%. After an initial response, however, the tumor was progressive again.
CONCLUSIONS: We describe here the first case of UPS-NF of the breast, which shows great clinical and histopathologic resemblances to previously reported UPS-NF of other anatomic localizations.

UNASSIGNED: Although the annual incidence of undifferentiated pleomorphic sarcoma (UPS) is extremely low, it can be subdivided into different subtypes. UPS with fever of unknown origin (also known as neoplastic fever) is a specific subtype of UPS, which shows certain clinical features that differentiate it from other UPS subtypes. However, no studies have focused on this rare UPS subtype. This study retrospectively analyzed the clinical data of patients with UPS to provide a reference for the diagnosis and treatment of UPS with neoplastic fever.
UNASSIGNED: This study included patients with UPS who were diagnosed and treated between June 2012 and June 2018. We examined whether these patients had a history of neoplastic fever. The characteristics of patients with UPS with neoplastic fever were summarized and analyzed.
UNASSIGNED: We reviewed the medical records of 183 patients with UPS. Seven (3.83%) of these patients had neoplastic fever. In patients with UPS with neoplastic fever, the primary lesions were located in the extremities and across the muscle space. In these patients, magnetic resonance imaging showed necrosis within the tumor body and extensive soft tissue edema around the tumor body. Patients with UPS with neoplastic fever had a lower metastasis rate (14.29% vs 44.94%) and a higher 3-year survival rate (85.71% vs 59.55%) than those without neoplastic fever.
UNASSIGNED: UPS with neoplastic fever is characterized by intratumoral necrosis and extensive edema of the surrounding soft tissues. Patients with UPS with neoplastic fever may have a better prognosis than those without neoplastic fever.

UNASSIGNED: Cancer patients have been disproportionally affected by the coronavirus disease 2019 (COVID-19) pandemic, with high rates of severe outcomes and mortality. Fever is the most common symptom in COVID-19 patients. During the COVID-19 pandemic, physicians may have difficulty in determining the cause of fever (COVID-19, another infection, or cancer fever) in cancer patients. Furthermore, there are no specific guidelines for managing cancer patients with fever during the COVID-19 pandemic. Thus, this study evaluated the clinical characteristics and outcomes of cancer patients with fever during the COVID-19 pandemic.
UNASSIGNED: This study retrospectively reviewed the medical records of 328 cancer patients with COVID-19 symptoms (fever) admitted to five hospitals in Daegu, Korea from January to October 2020. We obtained data on demographics, clinical manifestations, laboratory test results, chest computed tomography images, cancer history, cancer treatment, and outcomes of all enrolled patients from electronic medical records.
UNASSIGNED: The most common COVID-19-like symptoms were fever (n=256, 78%). Among 256 patients with fever, only three (1.2%) were diagnosed with COVID-19. Most patients (253, 98.8%) with fever were not diagnosed with COVID-19. The most common solid malignancies were lung cancer (65, 19.8%) and hepatobiliary cancer (61, 18.6%). Twenty patients with fever experienced a delay in receiving cancer treatment. Eighteen patients discontinued active cancer treatment because of fever. Major events during the treatment delay period included death (2.7%), cancer progression (1.5%), and major organ dysfunction (2.7%).
UNASSIGNED: Considering that only 0.9% of patients tested for COVID-19 were positive, screening for COVID-19 in cancer patients with fever should be based on the physician\'s clinical decision, and patients might not be routinely tested.

Metastatic prostate cancer can have an initial presentation with fever and systemic inflammatory response syndrome. Accurate diagnosis allows to differentiate this type of cancer from infectious conditions and to start early treatment. We report one case, in which the patient presented to the emergency department with lower urinary tract symptoms, fever and consumptive syndrome. Acute prostatitis was initially suspected, but subsequently prostate adenocarcinoma was diagnosed. This case enables us to consider the possibility of prostate adenocarcinoma as the diagnose in patients with fever of unknown origin, and the role of procalcitonin to rule out the presence of infection.

Hemodialysis patients have weakened immune systems and can exhibit fever due to various causes. Herein, we describe the case of a 61-year-old hemodialysis patient who exhibited intermittent low-grade fever after a pacemaker had been implanted 2 months before due to sick sinus syndrome. She had a medical history of subcutaneous sarcoidosis and uveitis. Active pulmonary sarcoidosis was diagnosed based on elevated soluble interleukin-2 receptor, elevated lysozyme level, and gallium-67 scintigraphy uptake in hilar and mediastinal lymph nodes. She was also diagnosed with renal cell carcinoma via contrast computed tomography. However, because her C-reactive protein level remained normal, the possibility of neoplastic fever was considered low. After the initiation of prednisolone administration, her fever gradually disappeared. Her serum soluble interleukin-2 receptor and lysozyme level improved in parallel with the enlargement of the mediastinal lymph node and gallium-67 scintigraphy uptake.

The development of fever is a common complication in the clinical course of cancer. If all other potential causes of fever are excluded, the possibility of neoplastic fever should be considered. The aim of the present study was to determine the incidence of neoplastic fever in patients with bone and soft tissue sarcomas. Between January 2009 and December 2014, 195 patients with bone and soft tissue sarcoma (111 men and 84 women; mean age, 55 years) were admitted to the Department of Orthopaedic Surgery of Mie University Graduate School of Medicine (Tsu, Japan). Episodes of fever were observed in 58 patients (30%), of whom 11 (5.5%) had neoplastic fever (mean maximum temperature, 38.9°C). The causes of neoplastic fever were as follows: Primary tumor (n=3), local recurrence (n=1), metastasis (n=5), and local recurrence with metastasis (n=2). Of the 11 patients, 9 were treated with naproxen and 8 exhibited a complete response, with their temperature normalizing to <37.3°C within 24 h. The 2 patients who were not treated with naproxen underwent surgical tumor resection, which resulted in prompt and complete lysis of the fever. In conclusion, neoplastic fever occurred in 5.5% of the 195 patients with bone and soft tissue sarcomas investigated herein. Naproxen may be effective for treating neoplastic fever in patients with bone and soft tissue sarcoma; however, radical tumor treatment may have to be considered to achieve permanent lysis of the fever.