“…All the patients sharedsimilarlaboratoryabnormalitieswithprofounddisturbances in the levels of potassium, calcium, phosphorus, and uricacid.Noneofthepatientshadanormalbaselineserum LDH,indicatingthatthecellularturnoverwasalreadyhighat thetimeofchemotherapyadministration.Table2summarizes themostrelevantlaboratoryvalues.Theprognosisisusually Keywords Tumor lysis syndrome · Small cell lung cancer · Spontaneous Introduction Tumorlysissyndrome(TLS)isoneoftheoncologicemergencies.Itresultsfromthelysisofalargenumberofmalignant cellswithreleaseofvariousanions,leadingtoprofoundmetabolic derangement and sometimes death [1,2]. It is usually encounteredinneoplasmscharacterizedbyhighcellularturnoverandpoordifferentiation,suchasaggressivehematologic malignancies,andcanoccureitherspontaneously,orshortly after the induction of chemotherapy, radiotherapy, or cytolyticantibodytherapy [3][4][5].Inadditiontohematologicmalignancies,TLShasalsobeenreportedinawidevarietyofsolid tumors [1],suchassmallcelllungcancer(SCLC),malignant tumorsofthebreast,ovary,vulva,liver,skin,softtissue,and germ cells. In this report we present, to our knowledge, the first case of spontaneous TLS in a 75-year-old woman with metastaticSCLC,andreviewthe11reportedcasesofTLSin SCLCpatients.…”