Below is an instruction that describes a task. Write a response that appropriately completes the request. ### Instruction: Juvenile Xanthogranuloma22m with two skin lesions that were biopsied and turned out to be "Juvenile Xanthogranuloma" (adult type).The PA who did the biopsy didn't seem too concerned. I'm a little confused as it seems that it normally happens to infants and I can't find much other information about this online except in medical journals.Some research says it's rare, while other research says as many as 1% of children can be affected and that it's usually underdiagnosed. One study says the average dermatologist sees 1-2 cases per year, which doesn't seem too rare to me. It seems that 10-20% of cases occur in the third decade of life (people my age).I am also slightly concerned about an association between multiple juvenile xanthogranuloma and "hematologic malignancies."What has been your experience with this as a dermatologist/GP/etc.? Is this rare? Do you ever see it in adults in their early 20s or teenagers? Would having two lesions count as "multiple JXG"? Do I need to be getting bloodwork done? It's been months since they first appeared and no other ones have appeared.These developed after I got the COVID vax's. Apparently JXG results from a "proliferation of histiocytes". Could this be due to the immune response caused by the vax? I have not found anything about this link in VAERS.. ### Response: 2=multipleThese are very uncommon in adults. Feel free to have a thorough investigation if you feel it is needed. The yield is very low.Your theory on pathogenesis is interesting and unprovable..