acute myeloid leukemia (AML)

M4eo AML most often in cases associated with inv(16); M4 also, but only in 2/3 of cases ,when +22 is apparently without inv(16); and eosinophilia may be missing in the latter case

young age, both in cases with or without inv(16)

inv(16) may be at increased CNS relapse when +22 is also present

a fair prognosis is associated with +22 accompanying inv(16), and with +22 solely, comparable to the prognosis associated with inv(16)

+22 is a frequent anomaly additional to inv(16), but was not found associated with other anomalies recurrently found in de novo AML; +22 may also occur apparently in the absence of inv(16), but cryptic rearrangements of MYH11 (16p13) and CBFB (16q22) have been found in a number of cases; for some authors, +22 indicates the obligate existence of an inv(16); for others +22 solely is a true entity

is appropriate to exclude or discover the presence of a hidden inv(16), inasmuch as inv(16) is associated with a relatively good prognosis

anomalies associated with +22 are del(7q) and/or +8, found in15% of cases each; this percentage is similar in cases with or without inv(16)

+22 is often associated with inv(16)(p13q22) or its equivalents; the existence of trisomy 22 solely is debated