Cannizzo, ElisaCarulli, GiovanniDel Vecchio, LuigiAzzarà, AntonioGalimberti, SaraOttaviano, VirginiaPreffer, FredericPetrini, Mario2013-03-292011Cannizzo, Elisa, Giovanni Carulli, Luigi Del Vecchio, Antonio Azzarà, Sara Galimberti, Virginia Ottaviano, Frederic Preffer, and Mario Petrini. 2011. Prethymic cytoplasmic CD3 negative acute lymphoblastic leukemia or acute undifferentiated leukemia: a case report. Case Reports in Hematology 2011:230568.2090-6560http://nrs.harvard.edu/urn-3:HUL.InstRepos:10473943Acute undiffentiated leukemia (AUL) is an acute leukemia with no more than one membrane marker of any given lineage. Blasts often express HLA-DR, CD34, and/or CD38 and may be positive for terminal deoxynucleotidyl transferase (TdT). The expression of CD34, HLA-DR, and CD38 has been shown in pro-T-ALL, although in this case, blasts should also express CD7 and cyCD3. However, some cases of T-ALL without CD3 in the cytoplasm and all TCR chain genes in germ line configuration are reported, features that fit well with a very early hematopoietic cell. We report a case of acute leukemia CD34+/−HLADR+CD7+CD38+cyCD3− in which a diagnosis of AUL was considered. However the blasts were also positive for CD99 and TCR delta gene rearrangement which was found on molecular studies. Therefore a differential diagnosis between AUL and an early cyCD3 negative T-ALL was debated.en-USJournal Article2013-03-2910.1155/2011/230568