Diagnosing neoplastic fever requires excluding identifiable causes, making it a diagnostic challenge. Fever as a primary manifestation of pancreatic adenocarcinoma is uncommon with few cases reported in the literature. Here we present an unusual case of metastatic pancreatic adenocarcinoma primarily manifesting as pyrexia of unknown origin. A 63-year-old Sri Lankan male, a non-smoker who was diagnosed with diabetes, hypertension and dyslipidaemia presented with a history of fever, anorexia and weight loss for 2 months. Despite the completion of treatment for positive serology for paratyphi, his symptoms and inflammatory markers remained elevated while the rest of the infectious screening was negative. On further evaluation, the patient was found to have a hypodense distal pancreas with ring-enhancing multiple liver lesions on imaging. Histology confirmed pancreatic adenocarcinoma with liver metastasis. Atypical liver metastases may present with evidence of ring enhancement in computed tomography imaging; thus, the biopsy is mandatory for diagnosis and decision-making. Usually, tumours of the pancreatic tail are resectable but if they are associated with liver metastatic disease, surgical resection is not recommended because it is not potentially curative. Therefore, in the context of metastatic pancreatic adenocarcinoma, palliative chemotherapy and pharmacological management of fever are required.

A 53-year-old otherwise healthy man was referred to our hospital with a fever of unknown origin, headache, and arthralgia. Four days earlier, he had a fever with chills. Treatment with antibiotics and acetaminophen proved ineffective, with the patient subsequently developing headache and joint pain. Blood analysis revealed elevated inflammatory markers, liver impairment, and severe thrombocytopenia (platelet count, 19,000/μL). Subsequent tests revealed elevated levels of anti-cytomegalovirus IgM and IgG. Based on these findings, the patient was diagnosed with severe thrombocytopenia associated with cytomegalovirus infection. Platelet counts increased spontaneously without antiviral therapy. Forty-five days after the initial visit, the symptoms improved, and blood tests revealed resolution of the inflammatory findings, with the platelet count recovering to 155,000/μL. Although the disease may resolve spontaneously, cytomegalovirus infection should be considered as a differential diagnosis in case of severe thrombocytopenia in immunocompetent adults.

BACKGROUND: Fever of unknown origin (FUO) is a diagnostic challenge with highly heterogeneous causes. Its etiology can change according to the studied regions, and the chance of reaching a diagnosis depends on available resources. The aim of this study is to describe the clinical characteristics, etiology and the usefulness of diagnostic aids in cases of FUO managed over 12 years in a Colombian reference center.
METHODS: Single-institution retrospective case series. All cases of FUO between 2006 and 2017 were identified with the help of an electronic medical record search software. Cases of adults with fever for more than three weeks who remained undiagnosed after three days of hospitalization are described.
RESULTS: Of 1,009 cases evaluated, 112 cases met the inclusion criteria (median age 43 years, 66% men). The etiologies identified were infectious (31.2%), inflammatory (20.5%), neoplastic (14.3%), and miscellaneous (2.7%) diseases. 31.2% remained without etiological diagnosis. The most frequent conditions were tuberculosis (17%), Hodgkin\'s lymphoma (7.1%), systemic lupus erythematosus (6.3%), disseminated histoplasmosis, and adult Still\'s disease. Contrast tomography and biopsies were the studies that most frequently supported or confirmed the final diagnosis.
CONCLUSIONS: This series of contemporary Latin American cases suggests that the categories of FUO etiologies are similar to those reported in studies from developed countries, with tuberculosis being the most frequent cause in our setting. Our results highlight the importance of tomography-guided invasive studies in the diagnostic approach to FUO.

Still\'s disease is frequently a condition of exclusion for patients with an unidentified cause of fever. Accompanying symptoms typically include fever, arthralgia, and a transient skin rash. The underlying pathophysiology indicates an autoimmune origin. Diagnosis is primarily clinical, often utilizing the Yamaguchi criteria. The case in question involves a 19-year-old male presenting with high-grade fever and paralytic ileus. The patient received intravenous glucocorticoids and cyclophosphamide, resulting in a rapid clinical improvement. During the follow-up, tofacitinib was initiated based on the clinical response observed.

BACKGROUND: Nocardia is an ubiquitous soil organism. As an opportunistic pathogen, inhalation and skin inoculation are the most common routes of infection. Lungs and skin are the most frequent sites of nocardiosis. Testis is a highly unusual location for nocardiosis.
METHODS: We report the case of an immunocompromised 75-year-old-man admitted for fever of unknown origin. He presented with skin lesions after gardening and was first suspected of Mediterranean spotted fever, but he did not respond to doxycycline. Then, physical examination revealed new left scrotal swelling that was compatible with a diagnosis of epididymo-orchitis. The patient\'s condition did not improve despite empirical antibiotic treatment with the onset of necrotic scrotal abscesses requiring surgery. Nocardia brasiliensis yielded from the removed testis culture. High-dose trimethoprim-sulfamethoxazole and ceftriaxone were started. Multiple micro-abscesses were found in the brain and spinal cord on imaging studies. After 6 weeks of dual antibiotic therapy for disseminated nocardiosis, slight regression of the brain abscesses was observed. The patient was discharged after a 6-month course of antibiotics and remained relapse-free at that time of writing these lines. Trimethoprim-sulfamethoxazole alone is meant to be pursued for 6 months thereafter. We undertook a literature review on previously reported cases of genitourinary and urological nocardiosis; to date, only 36 cases have been published with predominately involvement of kidney, prostate and testis.
CONCLUSIONS: To the best of our knowledge, this is the first case of Nocardia brasiliensis simultaneously infecting skin, testis, brain and spinal cord in an immunocompromised patient. Knowledge on uncommon forms of nocardiosis remains scarce. This case report highlights the difficulty of diagnosing atypical nocardiosis and the importance of prompt bacteriological sampling in case of empirical antibiotics failure.

Many clinical conditions can cause fever of unknown origin (FUO) in children, but the etiological diagnosis remains challenging despite the variety of inspection methods available at present. This study aims to investigate the effectiveness of droplet digital polymerase chain reaction (ddPCR) in identifying pathogens in children with FUO as a novel application. A 7-month-old boy failed to obtain etiology evidence for his disease through various tests. After collecting peripheral blood for ddPCR analysis, Staphylococcus aureus and Escherichia coli were detected, and Sanger sequencing confirmed the pathogens. During the disease, the child developed septic arthritis and osteomyelitis in the femur. Despite the patient\'s fever being removed, his limb activity improving, and inflammatory biomarkers decreasing, avascular necrosis of the femoral head remained after targeted antibiotic treatment and surgery. If the patient had undergone ddPCR analysis at an early stage, it may be possible to avoid sequelae. ddPCR helps identify pathogens in the diagnosis of children with FUO and could be a promising complementary tool.

UNASSIGNED: Pyrexia of unknown origin can be caused due to numerous infective and noninfective causes. It poses a diagnostic dilemma to the clinicians and requires a myriad of investigations for the confirmation of diagnosis. Thymomas are rare mediastinal tumors that present as anterior mediastinal mass; however, thymomas presenting as pyrexia of unknown origin has rarely been reported in the literature. We report an interesting case of a middle-aged male who presented as pyrexia of unknown origin due to thymoma.

A 48-year-old male was admitted to Peking Union Medical College Hospital presented with intermittent fever for two years. The maximum body temperature was 39 ℃, and could spontaneously relieve. The efficacy of antibacterial treatment was poor. He had no other symptoms and positive signs. He had a significant weight loss, and the serum lactate dehydrogenase increased significantly. It was highly alert to be lymphoma, but bone marrow smear and pathology, and PET-CT had not shown obvious abnormalities. Considering high inflammatory indicators, increased ferritin and large spleen, the patient had high inflammatory status, and was treated with methylprednisolone. Then the patient\'s body temperature was normal, but the platelet decreased to 33×109/L. During hospitalization, he had suddenly hemoperitoneum and hemorrhagic shock. He was found spontaneous spleen rupture without obvious triggers, and underwent emergency splenectomy. The pathological diagnosis of spleen was diffuse large B-cell lymphoma.
患者男，48岁，因间断发热2年就诊。患者间断发热，体温最高39 ℃，可自行热退，抗菌治疗疗效不佳，入院后无其他伴随症状及阳性体征，曾有体重明显下降，外周血乳酸脱氢酶明显增高，临床高度警惕淋巴瘤，但骨髓穿刺及活检、PET-CT未见明显异常。因患者高热，炎症指标高，铁蛋白增高，伴脾大，考虑高炎症状态，淋巴瘤待除外。给予甲泼尼龙24 mg，每天2次。患者体温正常，但出现血小板进行性下降至33×109/L。住院期间出现腹腔内出血、出血性休克，急诊手术发现患者为自发性脾破裂，行急诊脾切除术，脾脏病理诊断为弥漫性大B细胞淋巴瘤。.

A 64-year-old African American male with a history of hypertension and type II diabetes mellitus presented with unexplained upper lip lacerations after several frequent episodes of hemoptysis. Following the upper lip lacerations were several weeks of intermittent unknown episodic fevers. The patient, challenged by impaired mobility, exhibited an array of symptoms, including severe upper lip pain with lacerations and white patches on the tongue. Laboratory findings indicated thrombocytopenia and anemia, with positive tests for both influenza A and B. Despite completing Tamiflu, the patient experienced recurrent fevers. Imaging revealed gastrointestinal abnormalities, leading to the initiation of nystatin and a multi-antibiotic regimen without significant fever resolution. A subsequent tongue biopsy revealed verruca lesions, and acyclovir was initiated. Despite this, the patient developed lip and facial blisters. Negative results from cytomegalovirus (CMV) deoxyribonucleic acid (DNA) polymerase chain reaction (PCR) prompted a shift in focus to managing persistent fevers, ultimately controlled with naproxen but without discoverable cause. This case underscores the diagnostic challenge posed by unexplained fevers in an elderly patient with oral manifestations. The protracted course and evolving symptoms emphasize the intricacies of managing such cases, highlighting the need for continued investigation and collaboration across medical disciplines in navigating complex clinical scenarios.

Adult-onset Still\'s disease (AOSD) is a rare systemic inflammatory disorder. Diagnosis can take a long time, especially in the presence of confounding factors, and it is, to some extent, a process of exclusion. AOSD has life-threating complications ranging from asymptomatic to severe, such as macrophage activation syndrome (MAS), which is also referred to as hemophagocytic lymphohistocytosis (HLH). This condition is correlated with cytokine storm production and monocyte/macrophage overactivation and typically occurs with rash, pyrexia, pancytopenia, hepatosplenomegaly and systemic involvement. Exitus occurs in approximately 10% of cases. For the treatment of MAS-HLH, the Histiocyte Society currently suggests high-dose corticosteroids, with the possible addition of cyclosporine A, anti-interleukin (IL)-1, or IL-6 biological drugs; the inclusion of etoposide is recommended for the most severe conditions. In all cases, a multidisciplinary collaboration involving the resources and expertise of several specialists (e.g., rheumatologist, infectiologist, critical care medicine specialist) is advised. Herein, we provide a detailed description of the clinical case of a previously healthy young woman in which MAS developed as a dramatic onset manifestation of AOSD and whose diagnosis posed a real clinical challenge; the condition was finally resolved by applying the HLH-94 protocol (i.e., etoposide in combination with dexamethasone).