Histiocytosis wani yanayi ne na likitanci da ke tattare da yaɗuwar ƙwayoyin histiocytes, waɗanda wani nau'in farin jini ne wanda ke taka rawa a tsarin garkuwar jiki. Kalmar histiocytosis ta ƙunshi rukuni na rikice-rikice waɗanda suka haɗa da adadi mai yawa na histiocytes suna tarawa a cikin kyallen jikin jiki daban-daban, wanda ke haifar da kewayon alamomi da rikitarwa. Histiocytosis na iya shafar gabobin jiki da tsarin daban-daban, kamar kasusuwa, fata, huhu, hanta, saifa, nodes na lymph, da tsarin juyayi na tsakiya. Tsanani da tsinkayar histiocytosis ya dogara ne akan nau'in cutar, girman shigar nama, da shekaru da lafiyar majiyyaci gabaɗaya.