A B-cell lymphoma-associated chromosomal translocation in a progressive transformation of germinal center.

Progressive transformation of germinal center (PTGC) is a pattern of lymph node reactive hyperplasia. It can also be the predominant pattern in a hyperplastic lymph node known as florid PTGC. It is characterized histologically by the expansion of the mantle zone lymphocytes into both the adjacent sinusoids and germinal centers.

Rearrangement of the MLL gene and a region proximal to the RARalpha gene in a case of acute myelocytic leukemia M5 with a t(11;17)(q23;q21).

A case of acute myelocytic leukemia (AML) M5 subtype (French-American-British classification), in a 13-year-old girl showed the abnormal karyotype 46,XX,t(11;17)(q23;q21) in all bone marrow cells analyzed. Rearrangements involving 11q23 are frequent in cases of AML M5 and often involve the MLL gene. Nevertheless, t(11;17)(q23;q21) is very rare in this type of leukemia.