Granulocytic sarcoma associated with a der(7;12)(q10;q10)

Myeloid sarcoma: clinico-pathologic, phenotypic and cytogenetic analysis of 92 adult patients

Myeloid sarcoma (MS) is a rare neoplasm whose knowledge is largely based on case reports and/or technically dated contributions. Ninety-two MSs in adulthood with clinical data available were evaluated both morphologically and immunohistochemically. Seventy-four cases were also studied by fluorescent in situ hybridization on tissue sections and/or conventional karyotyping on bone marrow or peripheral blood. Histologically, 50% of the tumors were of the blastic type, 43.5% either monoblastic or myelomonocytic and 6.5% corresponded to different histotypes. CD68/KP1 was the most commonly expressed marker (100%), followed by myeloperoxidase (83.6%), CD117 (80.4%), CD99 (54.3%), CD68/PG-M1 (51%), CD34 (43.4%), terminal-deoxy-nucleotidyl-transferase (31.5%), CD56 (13%), CD61/linker for activation of T cells (2.2%), CD30 (2.2%) and CD4 (1.1%). Foci of plasmacytoid monocyte differentiation were observed in intestinal cases carrying inv16. Chromosomal aberrations were detected in about 54% of cases: monosomy 7(10.8%), trisomy 8(10.4%) and mixed lineage leukemia-splitting (8.5%) were the commonest abnormalities, whereas t(8;21) was rare (2.2%). The behavior was dramatic irrespective of presentation, age, sex, phenotype and cytogenetics. Most if not all, long survivors received bone-marrow transplantation. The present report expands the spectrum of our knowledge showing that MS has frequent monoblastic/myelomonocytic differentiation, displays distinctive phenotypic profile, carries chromosomal aberrations other than t(8;21), and requires supra-maximal therapy.

Isodicentric Philadelphia chromosome in acute lymphoblastic leukemia with der(7;12)(q10;q10)

We describe here the first case of acute lymphoblastic leukemia (ALL) with an isodicentric Philadelphia [idic(Ph)] chromosome. A 35-year-old man was diagnosed as ALL because of the infiltration of CD10(+)CD19(+)CD33(+)CD34(+) lymphoblasts in the bone marrow and the expression of p190-type BCR/ABL fusion transcript. Chromosome analysis showed 45,XY,der(7;12)(q10;q10),der(9)t(9;22)(q34;q11),idic der(22)t(9;22)(q34;q11). The idic(Ph) chromosome was spindle-shaped and supposed to be formed by two Ph chromosomes joined at their q terminals, whereas idic(Ph) chromosomes in chronic myelogenous leukemia (CML) have been shown to be fused at the satellite regions of p arms. The results indicate that the structure of idic(Ph) chromosomes appears to be different between ALL and CML. The patient did not respond to any chemotherapy and could not achieve remission. This chromosome aberration in ALL may suggest poor prognosis as observed in some cases of CML. Furthermore, considering other three reported cases, der(7;12)(q10;q10) may be one of the recurrent translocations in ALL.