Hairy cell leukemia involving blood/marrow. Patient presented with cytopenias. Marrow not terribly hypercellular, so very easy to overlook an infiltrate like this if the flow isn't positive. #hemepath #pathology
Flow cytometry showed characteristic CD123 and bright CD25 expression. HCL tends to have brighter CD45 expression/higher SSC than other B-cell lymphomas. Always check the monocyte gate-- I've seen false negative flow studies on HCL cases when reviewing the dot plots on consults.
@mjcascio @auerglass @KMirza @AmeetRKini @bethmcm @evemariecrane @DanBabuMD @HoratiuOlteanu CD3 and CD20, every time on every marrow for cytopenias. HCL can be soooo sneaky!
@mjcascio @auerglass @pwraess @KMirza @AmeetRKini @evemariecrane @DanBabuMD @HoratiuOlteanu I always tell residents not to forget about HCL I’m testing situations (and life). It likes to pull tricks on us...
@mjcascio @auerglass @pwraess @KMirza @AmeetRKini @bethmcm @evemariecrane @DanBabuMD @HoratiuOlteanu I had a case that picked up a small HCL clone on flow, marrow v hypo. Patient referred after profound cytopenias after chemo for lung ca.Interestingly had isolated monocytopenia before chemo. Flow invaluable to pick out the needle from the haystack!
@mjcascio @auerglass @pwraess @KMirza @AmeetRKini @bethmcm @evemariecrane @DanBabuMD @HoratiuOlteanu Nice case CD20 IHC will highlight the pattern of infiltration .
@mjcascio @auerglass @pwraess @KMirza @AmeetRKini @bethmcm @evemariecrane @DanBabuMD @HoratiuOlteanu Usually BRAF positive, also.
@mjcascio @evemariecrane @auerglass @pwraess @KMirza @AmeetRKini @bethmcm @DanBabuMD @HoratiuOlteanu fried egg appearance 🌹