Trisomy 15 as a single autosomal abnormality in a patient with unclassifiable myelodysplastic syndromes

Isolated +15 in bone marrow: disease-associated or a benign finding?

It has been controversial if trisomy 15 (+15) as an isolated clonal cytogenetic abnormality in bone marrow (BM) is disease-associated or a benign finding. To answer this question, we retrospectively reviewed our cytogenetic archives and identified 31 patients with isolated +15. Four patients presented with acute myeloid leukemia (AML), +15 was the major clone (56-95% of interphases) in BM and the clonal size of +15 was correlated with blast burden and disease status. For the remaining 27 patients, +15 was a minor clone (3-24% of interphases) in BM. Eighteen patients had a history of cytotoxic therapies and developed +15 after a median latency interval of 34 months. Six patients had BM involvement by lymphoma or myeloma, and +15 was exclusively detected in myeloid and erythroid cells, not in lymphoma or myeloma cells. With a median follow-up of 28 months, none of these 27 patients had clinical or morphological evidence of myelodysplastic syndromes. We conclude that +15 can be associated with AML, but more often isolated +15 presents as a minor clone in BM, and may not be disease associated. Clinical follow-up rather than an immediate therapeutic intervention seems most appropriate for non-leukemic patients with isolated +15.

Trisomy 15 as the sole abnormality in myelodysplastic syndromes: case report and review of the literature

Trisomy 15 as the sole autosomal anomaly is uncommon in hematological malignancies but could be preferentially associated with myelodysplasia. We report a 61-year-old man who developed pancytopenia following two courses of chemotherapy for chronic lymphoid leukemia. Cytogenetic studies at diagnosis of pancytopenia with R banding showed a 47,XY, + 15[3]/45,X[3]/46,XY[14] karyotype. A review of the 53 cases of myelodysplastic syndromes (MDS) and myeloid related disorders associated with trisomy 15 reported in the literature showed that 18 of the 31 men also lost the Y chromosome in the trisomic 15 cell line. Their mean age was significantly higher than that of males who had not lost the Y chromosome (p < 0.05). The main feature of the patient reported here is the presence of two abnormal cell lines, one having lost the Y chromosome, the other having gained a chromosome 15. Therefore, the two events occurred independently, the loss of the Y chromosome being possibly due to aging and the trisomy 15 to the hematologic disorder.

Duplication 15q as the sole anomaly in an acute promyelocytic leukemia patient without t(15;17)

We present a unique chromosomal abnormality found in a patient with acute myeloblastic leukemia of French-American-British subtype M3. The patient was referred for an evaluation of a chromosomal anomaly exclusively associated with FAB M3 or acute promyelocytic leukemia: a translocation between chromosomes 15 and 17, t(15;17)(q22;q21.1). Neither t(15;17) nor rearrangement of RARalpha was detected by routine G-banded chromosome as well as fluorescence in situ hybridization analysis using the commercial dual-color PML/RARalpha translocation probe and the RARalpha probe, a break apart rearrangement dual-color probe. Instead of the typical rearrangement between chromosomes 15 and 17, all cells analyzed had a duplication of the segment of chromosome 15 between bands 15q15 and 15q26.

Cytogenetic survey of 117 Tunisian patients with de novo myelodysplastic syndrome

Cytogenetic studies were performed on 117 Tunisian patients with de novo myelodysplastic syndromes (MDS). According to the French-American-British (FAB) criteria 40 patients presented with refractory anaemia (RA, 34%), eight with refractory anaemia with ringed sideroblasts (RARAS, 7%), 19 with refractory anaemia with excess of blasts (RAEB, 16%), 16 with refractory anaemia with excess of blasts in transformation (RAEB-t, 14%), 18 had chronic myelomonocytic leukaemia (CMML, 15%) and 16 unclassifiable MDS (14%). Seventy-five were men and forty-two were women. Five were children and 112 were adults with a median age of 58 years. Fifty-five per cent of the patients presented clonal chromosome abnormalities. Rates of abnormality varied from one FAB subtype to the other: 55% in RA, 75% in RARAS, 63% in RAEB, 75% in RAEB-t and 28% in CMML. The most frequent chromosome abnormalities were del(5q) (22 cases), monosomy 7 (12 cases), del(12p) (6 cases), and trisomy 8 (5 cases). Rare abnormalities were also found: ring of chromosome 12 and trisomy 15. Conventional cytogenetics remains the basic technique in identifying chromosomal abnormalities associated with MDS.

Duplication 15q in a patient with t(8;21) acute myeloblastic leukemia (M2)

We present unique chromosomal abnormalities found in a patient with acute myeloblastic leukemia (AML) of French-American-British subtype M2. The patient was referred for an evaluation of chromosomal anomaly associated with AML. She was found to have an abnormal karyotype 46,XX,t(8;21)(q22;q22), and a questionable dup(15)(q15q22) in the majority of cells analyzed. Two cells had the same chromosomal anomalies plus a duplicated derivative chromosome 21 [der(21)t(8;21)(q22;q22)]. These cytogenetic findings were confirmed by fluorescence in situ hybridization utilizing the appropriate DNA probes. To our knowledge, this is the first case report of a combination of the translocation between chromosomes 8 and 21, a duplication of chromosome 15 [dup(15)(q15q22), and a duplicated derivative chromosome 21 [der(21)t(8;21)(q22;q22)].