Deletion 12p in De Novo Acute Myeloid Leukemia An Association with Early Progenitor Cell L. C. Chan, Y. L. Kwong, H. W. Liu, C. P. Lee, K. W. Lie, and A. Y. Y. Chan
ABSTRACT: Deletion of the short arm of chromosome 12 as the sole karyotypic abnormality was found in three cases of acute myeloblastic leukemia (AML). In contrast to what has previously been reported in the literature, none of our cases had an antecedent history of m y e l o d y s p l a s i a or toxic exposure, and basophilia was absent. Two cases were terminal deoxynucleotidyl transferase (TdT) positive, suggesting i n v o l v e m e n t of an early progenitor cell.
INTRODUCTION
Deletion of the short arm of chromosome 12 has been de° scribed in patients with acute myeloblastic leukemia (AML), myelodysplasia (MDS), and secondary AML [1-3]. It is seen predominantly in MDS and AML secondary to toxic exposure, and is frequently associated with other chromosomal abnormalities [4]. As the sole karyotypic abnormality it has been described in 12 cases of de novo AML [5]. An association of 1 2 p - and AML M2 with basophilia had also been described [6, 7]. We report three cases of AML with del(12p), in which the features were different from those reported.
11.0 g/dl, WBC: 490 x 109/L (95% blasts), plat: 79 x 109/ L. Bone marrow examination showed AML. She went into coma 1 day after admission and died before effective chemotherapy could be started. Case 3
A 75-year-old man presented with symptoms of anemia. There was no relevant history of medical illness. Physical examination showed splenomegaly of 2 cm. Blood counts showed Hb: 8.6 g/dl, WBC: 261 x 109/L, plat: 77 x 109/L. Bone marrow examination showed AML. He was treated with Ara-C (85 mg b.d. x 5 days) and etoposide (100 mg q.d. x 5 days) but developed septicemia and died 1 week after admission.
CASE REPORTS Case 1
An 82-year-old woman presented with bleeding tendency. There was no relevant history of toxic exposure or hematological disorders. Physical examination showed pallor and bruises. Blood counts showed hemoglobin (Hb): 7.1 g/dl, white cell count (WBC): 2.8 x 109/L (50% blasts), platelets (plat): 77 x 10~/L. Bone marrow examination showed acute myeloid leukemia (AML). In view of her age, she was treated with Ara-C (100 mg b.d.) and thioguanine (100 mg q.d.) but developed septicemia and died 4 days after admission. Case 2
A 34-year-old woman presented with fever and bleeding. Past health was unremarkable. Physical examination showed generalized petechiae. Blood counts showed Hb:
From the Haematology Section, Department of Pathology and Department of Medicine (K. W. L.), University of Hong Kong,Queen Mary Hospital, Hong Kong. Address reprint requests to: Dr. L. C. Chan, Haematology Section, Department of Pathology, University of Hong Kong, LG2, K block, Queen Mary Hospital, Pokfulam Road, Hong Kong. Received March 25, 1992; accepted April 20, 1992.
MATERIALS AND METHODS
Bone marrows from patients were examined at initial presentation. The leukemia was classified according to FAB criteria [8]. Marrow cells were examined for metachromasia with toluidine blue. Immunophenotyping was performed by the alkaline phosphatase anti-alkaline phosphatase method with a panel of monoclonal antibodies including anti HLA-Dr, terminal deoxynucleotidyl transferase (TdT), CD19, CD10, CD20, CD22 (B lineage markers), CD7, CD5, CD2, CD3, CD4, CD8 (T lineage markers), CD34, CD33, CD13, CD14 (myeloid markers), CD41, and CD61 (megakaryocytic markers). Cytogenetic analysis was performed by flurodeoxyuridine synchronized cultures as previously de° scribed [9]. Metaphase chromosomes were banded by trypsin-Giemsa and kayotyped according to ISCN 1985. RESULTS
The FAB subtype, results of immunophenotyping and cytogenetics, of the three patients are shown in Table 1. All cases were strongly positive for Sudan black B and variably positive for myeloperoxidase. According to FAB criteria, two cases were classified as M1, and one as M2. Basophilia 47
© 1992 Elsevier Science Publishing Co., Inc. 655 A v e n u e of the Americas, New York, NY 10010
Cancer Genet Cytogenet 62:47 49 (1992)
0165-4608/92/$05.00
48
Table 1
1,. {:. Chan {:t al,
Diagnosis, cytochemistry, i m m u n o p h e n o t y p i n g , and cytogenetic results of the 3 cases
Case
FAB
% Blast
1
M1
90
SBB + (50%]
TdT+ (40%), CD7 + (90%)
2
M1
96
CD15 + (25%), CD14 + (70%)
3
M2
50
SBB + (50%) MPO + (15o/,,) SBB + (60%) MPO + {10%)
Abbreviations:
Cytochemistry
hnmunophenotype
Karyotype[no of cells] 46,XX{l~ 46,XX,del(12)(p11)[gl 46,XX,del(l 2)(pl 1)[6l
TdT+ (40%), CD34 + (4O%), CD13 ÷ {30%), CD15 + (60%), CDllb + (40%)
46,XY~5] 46,XY,del(12)(pl 1)[3]
SBB, Sudan black B; MPO, myeloperoxidase.
was absent morphologically and no metachromasia was seen on toluidine blue staining. While i m m u n o p h e n o t y p ing of blast cells confirmed myeloid lineage involvement in case 2, the results for cases 1 and 3 revealed some interesting features. Case i showed a pre-T phenotype based on reactivity with TdT and CD7, whereas in case 3, TdT and myeloid antigens were present, as well as CD34, a stem cell marker. In all three of the cases, del(12)(p11) was found as the sole karyotypic abnormality. Partial karotypes of the cases were s h o w n in Figure 1. DISCUSSION Del(12p) is often found associated with other chromosomal abnormalities and it has been suggested that it may be a secondary step in part of the multi-step neoplastic process [2, 3]. However, del(12p) has been described to be the sole karyotypic abnormality in a diversity of hemic malignancies i n c l u d i n g AML, MDS [10], myeloproliferative disorders [11], and acute lymphoblastic leukemia [12, 13]. Of the 12 cases of AML with del(12p) as the sole karyotypic abnormality catalogued by Mitelman [5], most are single case reports in w h i c h the morphology and i m m u n o p h e n o typing of the AML were not described. Berger and Daniel et al. [1, 6] reported an association between del(12p) and secondary AML, or de novo AML with basophilia. The MIC group classified this as M2Baso/t(12p) [7]. Such features were not found in our three cases, therefore showing that in de novo AML, del(12p) is not necessarily associated with M2, nor with basophilia. It is of interest that two of our three cases (cases 1 and 3) with u n e q u i v o c a l characteristics of AML based on FAB criteria had i m m u n o p h e n o t y p i c evidence of TdT, a marker of l y m p h o i d progenitor cell. The presence of TdT in AML
Figure 1
has previously been shown to be particularly correlated with immature myeloblastic leukemia and less differentiated AML subtypes [14]. Additionally, case 1 expressed CD7, a marker associated with early T-cell precursors [15] and cell immaturity in AML [16]; and case 3 expressed CD34, a stem cell antigen [17]. Taken together, our data suggest leukemic i n v o l v e m e n t of an early progenitor in 2 of our cases. Whether del(12p) is a marker of transformation of an early progenitor cell or a multipotential stem cell, as suggested by our data and the observation of its i n v o l v e m e n t in heroic malignancies of different lineages, will await studies c o m b i n i n g i m m u n o phenotyping and karyotypic analysis as well as cloning of the putative gene on 12p. The authors wish to thank Ms. L M Ching and Mr. Thomas Wan for expert assistance in cytogenetics, and Prof. T. K. Chan for clinical details of the reported cases.
REFERENCES 1. Wilmoth D, Feder M, Finan J, Nowell PC (1985): Preleukemia and leukemia with 12p- and 19q+ chromosome alterations following alkeran therapy. Cancer Genet Cytogenet 15:95-98. 2. Berger R, Bernheim A, Le Coniat M, Vecchione D, Pacot A, Daniel MT, Flandrin G (1986): Abnormalities of the short arm of chromosome 12 in acute nonlymphocytic leukemia and dysmyelopoietic syndrome. Cancer Genet Cytogenet 19:281-289. 3. Sandberg AA (1990): The Chromosomes in Human Cancer and Leukemia. Elsevier, New York, pp. 566-567, 4. Trent JM, Kaneko Y, Mitelman F (1989): Report on the Committee on Structural Chromosome Changes in Neoplasia. Human Gene Mapping 10 (1989): Tenth International Workshop on Human Gene Mapping. Cytogenet Cell Genet 51:533-562.
Partial karyotype of the three cases, showing del(12)(p11). The breakpoints are marked by arrows.
12 Case
12pI
12
12p-
Case2
12 Case
12p3
D e l e t i o n 12p in A M L
5. Mitelman F (1991): Catalog of Chromosome Aberrations in Cancer. Wiley-Liss, New York, pp. 923-931. 6. Daniel MT, Bernheim A, Flandrin G, Berger R (1985): Leuc~mie aigue my~loblastique (M2) avec atteinte de la lign~e basophile et anomalies du bras court du chromosome 12(12p). C R A c a d Sc 301:299-301. 7. Second MIC Cooperative Study Group (1988): Morphologic, immunologic and cytogenetic (MIC} working classification of the acute myeloid leukaemias. Br J Haematol 68:487-494. 8. Bennett JM, Catovsky D, Daniel MT, Flandrin G, Galton DAG, Gralnick HR, Sultan C (1985): Proposed revised criteria for the classification of acute myeloid leukemia. Ann Intern Med 103:626-629. 9. Chan LC, Kwong YL, Liu HW, Chan TK, Todd D, Ching LM (1992): Cytogenetic analysis of haematological malignancies in Hong Kong--A study of 98 cases. Cancer Genet Cytogenet (in press). 10. GFCH (Groupe Francais de Cytogenetique Hematologique) (1986): Cytogenetics of chronic myelomonocytic leukemia. Cancer Genet Cytogenet 21:11-30. 11. Swolin B, Weinfeld A, Westin J (1988): A prospective longterm cytogenetic study in polycythemia vera in relation to treatment and clinical course. Blood 72:386-395.
49
12. Raimondi SC, Williams DL, Callihan T, Peiper S, Rivera GK, Murphy SB (1986): Nonrandom involvement of the 12p12 breakpoint in chromosome abnormalities of childhood acute lymphoblastic leukemia. Blood 68:69-75. 13. Berger R, Le Coniat M, Vecchione D, Derre J and Chen SJ (1990): Cytogenetic studies of 44 T-cell acute lymphoblastic leukemias. Cancer Genet Cytogenet 44:69-75. 14. Parreira A, Pombo de Oliveira MS, Matutes E, Foroni L, Morilla R, Catovsky D (1988): Terminal deoxynucleotidyl transferase positive acute myeloid leukaemia: an association with immature myeloblastic leukaemia. Br J Haematol 69:219-224. 15. Vodinelich L, Tax W, Bai Y, Pegram S, Capel P, Greaves MF (1983): A monoclonal antibody (WT1) for detecting leukemias of T-cell precursors (T-ALL). Blood 62:1108-1113. 16. Lo Coco F, De Rossi G, Pasqualetti D, Lopez M, Diverio D, Latagliata R, Fenu S, Mandelli F (1989): CD7 positive acute myeloid leukaemia: a subtype associated with cell immaturity. Br J Haematol 73:480-485. 17. Vaughan WP, Civin CI, Weisenhurger DD, Karp JE, Graham ML, Sanger WG, Grierson HL, Joshi SS, Burke P (1988): Acute leukemia expressing the normal hematopoiteic stem cell membrane glycoprotein CD34 (MYIO). Leukemia 2:661-666.
ABSTRACT: Deletion of the short arm of chromosome 12 as the sole karyotypic abnormality was found in three cases of acute myeloblastic leukemia (AML). In contrast to what has previously been reported in the literature, none of our cases had an antecedent history of m y e l o d y s p l a s i a or toxic exposure, and basophilia was absent. Two cases were terminal deoxynucleotidyl transferase (TdT) positive, suggesting i n v o l v e m e n t of an early progenitor cell.
INTRODUCTION
Deletion of the short arm of chromosome 12 has been de° scribed in patients with acute myeloblastic leukemia (AML), myelodysplasia (MDS), and secondary AML [1-3]. It is seen predominantly in MDS and AML secondary to toxic exposure, and is frequently associated with other chromosomal abnormalities [4]. As the sole karyotypic abnormality it has been described in 12 cases of de novo AML [5]. An association of 1 2 p - and AML M2 with basophilia had also been described [6, 7]. We report three cases of AML with del(12p), in which the features were different from those reported.
11.0 g/dl, WBC: 490 x 109/L (95% blasts), plat: 79 x 109/ L. Bone marrow examination showed AML. She went into coma 1 day after admission and died before effective chemotherapy could be started. Case 3
A 75-year-old man presented with symptoms of anemia. There was no relevant history of medical illness. Physical examination showed splenomegaly of 2 cm. Blood counts showed Hb: 8.6 g/dl, WBC: 261 x 109/L, plat: 77 x 109/L. Bone marrow examination showed AML. He was treated with Ara-C (85 mg b.d. x 5 days) and etoposide (100 mg q.d. x 5 days) but developed septicemia and died 1 week after admission.
CASE REPORTS Case 1
An 82-year-old woman presented with bleeding tendency. There was no relevant history of toxic exposure or hematological disorders. Physical examination showed pallor and bruises. Blood counts showed hemoglobin (Hb): 7.1 g/dl, white cell count (WBC): 2.8 x 109/L (50% blasts), platelets (plat): 77 x 10~/L. Bone marrow examination showed acute myeloid leukemia (AML). In view of her age, she was treated with Ara-C (100 mg b.d.) and thioguanine (100 mg q.d.) but developed septicemia and died 4 days after admission. Case 2
A 34-year-old woman presented with fever and bleeding. Past health was unremarkable. Physical examination showed generalized petechiae. Blood counts showed Hb:
From the Haematology Section, Department of Pathology and Department of Medicine (K. W. L.), University of Hong Kong,Queen Mary Hospital, Hong Kong. Address reprint requests to: Dr. L. C. Chan, Haematology Section, Department of Pathology, University of Hong Kong, LG2, K block, Queen Mary Hospital, Pokfulam Road, Hong Kong. Received March 25, 1992; accepted April 20, 1992.
MATERIALS AND METHODS
Bone marrows from patients were examined at initial presentation. The leukemia was classified according to FAB criteria [8]. Marrow cells were examined for metachromasia with toluidine blue. Immunophenotyping was performed by the alkaline phosphatase anti-alkaline phosphatase method with a panel of monoclonal antibodies including anti HLA-Dr, terminal deoxynucleotidyl transferase (TdT), CD19, CD10, CD20, CD22 (B lineage markers), CD7, CD5, CD2, CD3, CD4, CD8 (T lineage markers), CD34, CD33, CD13, CD14 (myeloid markers), CD41, and CD61 (megakaryocytic markers). Cytogenetic analysis was performed by flurodeoxyuridine synchronized cultures as previously de° scribed [9]. Metaphase chromosomes were banded by trypsin-Giemsa and kayotyped according to ISCN 1985. RESULTS
The FAB subtype, results of immunophenotyping and cytogenetics, of the three patients are shown in Table 1. All cases were strongly positive for Sudan black B and variably positive for myeloperoxidase. According to FAB criteria, two cases were classified as M1, and one as M2. Basophilia 47
© 1992 Elsevier Science Publishing Co., Inc. 655 A v e n u e of the Americas, New York, NY 10010
Cancer Genet Cytogenet 62:47 49 (1992)
0165-4608/92/$05.00
48
Table 1
1,. {:. Chan {:t al,
Diagnosis, cytochemistry, i m m u n o p h e n o t y p i n g , and cytogenetic results of the 3 cases
Case
FAB
% Blast
1
M1
90
SBB + (50%]
TdT+ (40%), CD7 + (90%)
2
M1
96
CD15 + (25%), CD14 + (70%)
3
M2
50
SBB + (50%) MPO + (15o/,,) SBB + (60%) MPO + {10%)
Abbreviations:
Cytochemistry
hnmunophenotype
Karyotype[no of cells] 46,XX{l~ 46,XX,del(12)(p11)[gl 46,XX,del(l 2)(pl 1)[6l
TdT+ (40%), CD34 + (4O%), CD13 ÷ {30%), CD15 + (60%), CDllb + (40%)
46,XY~5] 46,XY,del(12)(pl 1)[3]
SBB, Sudan black B; MPO, myeloperoxidase.
was absent morphologically and no metachromasia was seen on toluidine blue staining. While i m m u n o p h e n o t y p ing of blast cells confirmed myeloid lineage involvement in case 2, the results for cases 1 and 3 revealed some interesting features. Case i showed a pre-T phenotype based on reactivity with TdT and CD7, whereas in case 3, TdT and myeloid antigens were present, as well as CD34, a stem cell marker. In all three of the cases, del(12)(p11) was found as the sole karyotypic abnormality. Partial karotypes of the cases were s h o w n in Figure 1. DISCUSSION Del(12p) is often found associated with other chromosomal abnormalities and it has been suggested that it may be a secondary step in part of the multi-step neoplastic process [2, 3]. However, del(12p) has been described to be the sole karyotypic abnormality in a diversity of hemic malignancies i n c l u d i n g AML, MDS [10], myeloproliferative disorders [11], and acute lymphoblastic leukemia [12, 13]. Of the 12 cases of AML with del(12p) as the sole karyotypic abnormality catalogued by Mitelman [5], most are single case reports in w h i c h the morphology and i m m u n o p h e n o typing of the AML were not described. Berger and Daniel et al. [1, 6] reported an association between del(12p) and secondary AML, or de novo AML with basophilia. The MIC group classified this as M2Baso/t(12p) [7]. Such features were not found in our three cases, therefore showing that in de novo AML, del(12p) is not necessarily associated with M2, nor with basophilia. It is of interest that two of our three cases (cases 1 and 3) with u n e q u i v o c a l characteristics of AML based on FAB criteria had i m m u n o p h e n o t y p i c evidence of TdT, a marker of l y m p h o i d progenitor cell. The presence of TdT in AML
Figure 1
has previously been shown to be particularly correlated with immature myeloblastic leukemia and less differentiated AML subtypes [14]. Additionally, case 1 expressed CD7, a marker associated with early T-cell precursors [15] and cell immaturity in AML [16]; and case 3 expressed CD34, a stem cell antigen [17]. Taken together, our data suggest leukemic i n v o l v e m e n t of an early progenitor in 2 of our cases. Whether del(12p) is a marker of transformation of an early progenitor cell or a multipotential stem cell, as suggested by our data and the observation of its i n v o l v e m e n t in heroic malignancies of different lineages, will await studies c o m b i n i n g i m m u n o phenotyping and karyotypic analysis as well as cloning of the putative gene on 12p. The authors wish to thank Ms. L M Ching and Mr. Thomas Wan for expert assistance in cytogenetics, and Prof. T. K. Chan for clinical details of the reported cases.
REFERENCES 1. Wilmoth D, Feder M, Finan J, Nowell PC (1985): Preleukemia and leukemia with 12p- and 19q+ chromosome alterations following alkeran therapy. Cancer Genet Cytogenet 15:95-98. 2. Berger R, Bernheim A, Le Coniat M, Vecchione D, Pacot A, Daniel MT, Flandrin G (1986): Abnormalities of the short arm of chromosome 12 in acute nonlymphocytic leukemia and dysmyelopoietic syndrome. Cancer Genet Cytogenet 19:281-289. 3. Sandberg AA (1990): The Chromosomes in Human Cancer and Leukemia. Elsevier, New York, pp. 566-567, 4. Trent JM, Kaneko Y, Mitelman F (1989): Report on the Committee on Structural Chromosome Changes in Neoplasia. Human Gene Mapping 10 (1989): Tenth International Workshop on Human Gene Mapping. Cytogenet Cell Genet 51:533-562.
Partial karyotype of the three cases, showing del(12)(p11). The breakpoints are marked by arrows.
12 Case
12pI
12
12p-
Case2
12 Case
12p3
D e l e t i o n 12p in A M L
5. Mitelman F (1991): Catalog of Chromosome Aberrations in Cancer. Wiley-Liss, New York, pp. 923-931. 6. Daniel MT, Bernheim A, Flandrin G, Berger R (1985): Leuc~mie aigue my~loblastique (M2) avec atteinte de la lign~e basophile et anomalies du bras court du chromosome 12(12p). C R A c a d Sc 301:299-301. 7. Second MIC Cooperative Study Group (1988): Morphologic, immunologic and cytogenetic (MIC} working classification of the acute myeloid leukaemias. Br J Haematol 68:487-494. 8. Bennett JM, Catovsky D, Daniel MT, Flandrin G, Galton DAG, Gralnick HR, Sultan C (1985): Proposed revised criteria for the classification of acute myeloid leukemia. Ann Intern Med 103:626-629. 9. Chan LC, Kwong YL, Liu HW, Chan TK, Todd D, Ching LM (1992): Cytogenetic analysis of haematological malignancies in Hong Kong--A study of 98 cases. Cancer Genet Cytogenet (in press). 10. GFCH (Groupe Francais de Cytogenetique Hematologique) (1986): Cytogenetics of chronic myelomonocytic leukemia. Cancer Genet Cytogenet 21:11-30. 11. Swolin B, Weinfeld A, Westin J (1988): A prospective longterm cytogenetic study in polycythemia vera in relation to treatment and clinical course. Blood 72:386-395.
49
12. Raimondi SC, Williams DL, Callihan T, Peiper S, Rivera GK, Murphy SB (1986): Nonrandom involvement of the 12p12 breakpoint in chromosome abnormalities of childhood acute lymphoblastic leukemia. Blood 68:69-75. 13. Berger R, Le Coniat M, Vecchione D, Derre J and Chen SJ (1990): Cytogenetic studies of 44 T-cell acute lymphoblastic leukemias. Cancer Genet Cytogenet 44:69-75. 14. Parreira A, Pombo de Oliveira MS, Matutes E, Foroni L, Morilla R, Catovsky D (1988): Terminal deoxynucleotidyl transferase positive acute myeloid leukaemia: an association with immature myeloblastic leukaemia. Br J Haematol 69:219-224. 15. Vodinelich L, Tax W, Bai Y, Pegram S, Capel P, Greaves MF (1983): A monoclonal antibody (WT1) for detecting leukemias of T-cell precursors (T-ALL). Blood 62:1108-1113. 16. Lo Coco F, De Rossi G, Pasqualetti D, Lopez M, Diverio D, Latagliata R, Fenu S, Mandelli F (1989): CD7 positive acute myeloid leukaemia: a subtype associated with cell immaturity. Br J Haematol 73:480-485. 17. Vaughan WP, Civin CI, Weisenhurger DD, Karp JE, Graham ML, Sanger WG, Grierson HL, Joshi SS, Burke P (1988): Acute leukemia expressing the normal hematopoiteic stem cell membrane glycoprotein CD34 (MYIO). Leukemia 2:661-666.
