Systemic inflammation caused by an intracranial mesenchymal tumor with a EWSR1::CREM fusion presenting associated with IL-6/STAT3 signaling.

Pediatric neoplastic diseases account for about 10% of cases of fever of unknown origin (FUO), and most neoplastic disease cases are leukemia, lymphoma, and neuroblastoma. Brain tumors are rarely reported as the cause of FUO, although craniopharyngioma, metastatic brain tumor, and Castleman's disease have been reported. We report a case of intracranial mesenchymal tumor (IMT) with a FET:CREB fusion gene, which had inflammatory phenotype without neurological signs. A 10-year-old girl was admitted with a 2-month history of intermittent fever and headache, whereas her past history as well as her family history lacked special events. Sepsis work-up showed no pathological organism, and empirical antibiotic therapy was not effective. Bone marrow examination showed a negative result. Cerebrospinal fluid examination showed elevated protein as well as cell counts, and head magnaetic resonance imaging showed a hypervascular mass lesion with contrast enhancement in the left cerebellar hemisphere. The patient underwent tumor excision, which made the intermittent fever disappear. Pathological examinations resembled those of classic angiomatoid fibrous histiocytoma (AFH), but the morphological features were distinct from the AFH myxoid variant; then we performed break-apart fluorescence in situ hybridization and confirmed the tumor harbored the rare EWSR1::CREM fusion gene (Ewing sarcoma breakpoint region 1 gene (EWSR1) and cAMP response element binding (CREB) family gene). Consequently, we diagnosed the condition as IMT with EWSR1::CREM fusion. Elevated serum concentration of interleukin 6 (IL-6) was normalized after tumor resection, which suggested the fever could be caused by tumor-derived IL-6. This is the first case of IMT with EWSR1::CREM fusion that showed paraneoplastic symptoms associated with the IL-6/signal transducer and activator of transcription 3 (STAT3) signaling pathway. Although brain tumors are rarely diagnosed as a responsible disease for FUO, they should be considered as a cause of unknown fever even in the absence of abnormal neurological findings.

Urinary stone in a 12-year-old adolescent with new-onset type 1 diabetes and diabetic ketoacidosis.

Dehydration and acidosis increase the risk for urinary stone formation. Urinary stones have been reported in three pediatric cases of diabetic ketoacidosis (DKA). A 24-h urine collection was performed for two of the three children. One patient had high urine sodium levels, while the other had low urine citrate excretion. We report the case of a 12-yr-old adolescent boy with urinary stones, new-onset type 1 diabetes mellitus (T1D), and DKA, excluding other metabolic disorders. After DKA was diagnosed, the patient received a 0.9% saline bolus and continuous insulin infusion. Hyperglycemia and ketoacidosis were well-controlled on the third day after admission. However, the patient developed abdominal pain radiating to the back. Urinary stones were suspected, and a urinalysis was performed. The patient's urine revealed significant elevation in red blood cells and calcium oxalate crystals. Computed tomography revealed a high-density left ureteric mass, suggestive of a urinary stone. Although both the previously reported pediatric cases involved metabolic diseases, additional tests in this patient excluded metabolic diseases other than T1D. DKA may be related to the formation of calcium oxalate crystals owing to dehydration and acidosis. Therefore, physicians should consider urinary stone formation in DKA patients.