Tetrasomy 8 is a rare, but non-random cytogenetic abnormality, primarily associated with myeloid disease. It has been described most frequently in AML. Only 11 cases of AML with tetrasomy 8 as the sole karyotypic abnormality have been reported. The majority of these were of monocytic derivation (FAB M5 or M4). Although treatment data is sparse, tetrasomy 8 has been associated with a poor prognosis. Polysomy 8 (pentasomy and hexasomy)is even rarer. At our institution, the incidence of tetrasomy or pentasomy 8 was 1.9% (8/412) among cases of AML karyotyped from 1/4/1994 to 9/13/99. Tetrasomy 8 was the sole abnormality in two (0.49%) and occurred with complex karyotypes in the remainder ( 1.5 %). An antecedent hématologie disorder (AMD) was present in 3/8 patients (one case of CML, two with MDS). We analyzed the clinical features and outcomes of 5 cases of de novo tetrasomy (n=4) and pentasomy (n= 1 ) AML. Four cases were monocytic (FAB M5a n=3, M5b n=l) and one was myelomonocytic (FAB M4). At diagnosis the median age was 73 years (range 42-77). Three of the five presented with bone pain and one had biopsy proven leukemia cutis. At diagnosis, the median WBC was 10.9 x 10(9)/1 (range 3.9-73.3), platelet count was 64 xlO(9)/l (range 10-215) and LDH was 1230 U/l (range 819-2894). Flow cytometric immunophenotyping on the two cases with isolated tetrasomy 8 demonstrated the blasts to express CDllb, CD13, CD 34 and CD 56. One patient (tetrasomy 8 with a complex karyotype) opted for palliative/ supportive care and died 4 weeks from diagnosis. Four patients received induction chemotherapy with an anthracycline and standard cytarabine and 3 achieved complete remission (CR). One (isolated tetrasomy 8) died unexpectedly on day 7 of induction. Three patients received consolidation with cytarabine-based chemotherapy. One relapsed after the first consolidation and declined further therapy. Two completed consolidation with high dose cytarabine and remained in CR for 14.5 and 64 months, respectively. At last follow up, one patient with isolated tetrasomy 8 remains alive in first CR at 65 months from diagnosis. The other relapsed at 14.5 months and died three months later of progressive disease following HLA-identical sibling allogeneic stem cell transplantation. Our experience confirms the preferential association of tetrasomy 8 with AML of a monocytic phenotype. Limited numbers prevent any assessment of prognosis with standard therapy, underscoring the need for further reporting of outcomes of this rare group of patients.
|Original language||English (US)|
|Issue number||11 PART II|
|State||Published - Jan 1 2000|
ASJC Scopus subject areas
- Cell Biology