Case Report Acta Haematol 2014;132:68–72 DOI: 10.1159/000355640
Received: June 20, 2013 Accepted after revision: September 14, 2013 Published online: January 24, 2014
Unusual Intracytoplasmic Crystalline Inclusions in Chronic Myelomonocytic Leukemia with Double Minute Chromosomes and MYC Amplification: A Rare Case Kanji Miyazaki Kenshi Suzuki Department of Hematology, Japanese Red Cross Medical Center, Tokyo, Japan
Key Words Chronic myelomonocytic leukemia · Double minute chromosomes · Intracytoplasmic inclusions
Abstract Chronic myelomonocytic leukemia (CMML) is a clonal hematological disease characterized by the presence of peripheral blood monocytosis and bone marrow dysplasia. Double minute chromosomes (dmin) are rare and intracytoplasmic crystalline inclusions are very rare in hematologic malignancies. We present a case of CMML with dmin and unusual intracytoplasmic crystalline inclusions. To our knowledge, no such case has previously been reported. © 2014 S. Karger AG, Basel
Introduction
Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic stem cell disorder. CMML is characterized by the presence of an absolute monocytosis (>1 × © 2014 S. Karger AG, Basel 0001–5792/14/1321–0068$39.50/0 E-Mail [email protected] www.karger.com/aha
109/l) in the peripheral blood and the presence of myelodysplastic and myeloproliferative features in the bone marrow, absence of the Philadelphia chromosome and the BCR-ABL1 fusion gene, absence of rearrangement of platelet-derived growth factors A (PDGFRA) and B (PDGFRB), 90%) infiltrated by myeloperoxidase positive cells without any signs of myelofibrosis and crystal-like inclusions were very scarce (fig. 2). On electron microscopy, well-demarcated rectangular intracytoplasmic crystal-like inclusions were seen. The inclusions were electron-dense, and were enclosed in intracytoplasmic membranes (fig. 3). The inclusions had 3-nm, periodic, lattice-like structures. Round inclusions were also electron-dense and were enclosed in cytoplasmic membranes, suggesting that these round inclusions are the same as rectangular ones and that these small electron-
dense inclusions might fuse together to form rectangular electrondense crystalline inclusions. Chromosomal analysis of 30 metaphases showed the presence of deletion 20q and dmin. The karyotype was described as 46, XY, del (20)(q11q13) [7]/46, XY, del (20)(q11q13), 1–10 dmin [16]/46, XY [5] (fig. 4). We performed fluorescence in situ hybridization (FISH) using an MYC/IgH probe set to further characterize the dmin. Deletion of the MYC gene on the #8 chromosome and amplification of the MYC gene in the form of dmin were confirmed (fig. 5). No BCR/ABL1 rearrangement was detectable in molecular genetic analysis. The patient was treated with azacitidine (75 mg/m2/day for 7 days, every 4 weeks) based on a diagnosis of CMML-2. After
Inclusions in CMML with Double Minute Chromosomes and MYC Amplification
Acta Haematol 2014;132:68–72 DOI: 10.1159/000355640
Fig. 2. Bone marrow biopsy. Myeloperoxidase. Bone marrow
biopsy revealed hypercellularity (>90%) infiltrated by myeloperoxidase positive cells. Crystal-like inclusions were very scarce.
69
a
b
c
d
e
f
Fig. 3. Electron-microscopic appearance of intracytoplasmic inclusions. a A rectangular electron-dense inclusion in a granulocyte. b, c The inclusion is enclosed in intracytoplasmic membranes. d Irregular shaped inclusions existed. e, f Square and round inclusions. They were also electron-dense.
1
6
Fig. 4. Representative karyotype demon-
strating the presence of dmin and the deletion of 20q.
70
Acta Haematol 2014;132:68–72 DOI: 10.1159/000355640
2
7
3
9
8
13
14
19
20
4
15
21
5
11
10
16
22
dmin
Miyazaki/Suzuki
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Y
MYC
IgH
a IgH MYC (dmin) MYC (dmin)
MYC (dmin)
MYC (dmin) MYC (dmin) MYC
MYC (dmin)
IgH MYC (dmin)
b
In all 3 cases, inclusions were absent in band forms and neutrophils, and absent in the peripheral blood. Two explanations are possible: the inclusions were dissolved or had been extruded from these cells, or the presence of the inclusions did not permit differentiation beyond the metamyelocyte stage. The fact that the inclusions were enclosed in intracytoplasmic membranes, which was not observed in the previous reports, suggests that these inclusions are an accumulation of protein material in the endoplasmic reticulum caused by abnormal metabolism of leukemic cells. In our case, both dmin and MYC amplification were observed, unlike the cases of Wolf et al. [5] and Felman et al. [6], and it seems the formation of intracytoplasmic crystalline inclusions is not related to MYC amplification. Double minutes are rare in hematologic malignancies and are associated with poor prognosis [3, 8, 9]. Almost all cases are acute leukemia. Some cases of myelodysplastic syndromes have been reported [7]. Usually dmin of the hematologic malignancy carry the MYC or KMT2A gene [10]. Our CMML-2 patient relapsed after the 6 cycles of azacitidine. The leukemic cells became resistant to cytotoxic chemotherapy. Although azacitidine is a reasonable treatment option for CMML [2, 11], CMML patients with dmin may be regarded as poor-risk patients and therefore considered suitable candidates for allogeneic stem cell transplantation.
Fig. 5. Interphase (a) and metaphase (b) FISH, showing numerous
extra copies of the MYC gene (red) as dmin.
References 2 cycles, the patient achieved complete remission (CR), according to the modified International Working Group criteria. After 6 cycles, the patient relapsed into CMML-2, underwent induction therapy (idarubicin and cytarabine) and died at 6 months due to uncontrolled CMML-2 from the CMML-2 diagnosis.
Discussion
The intracytoplasmic crystalline inclusions in this patient were distinctly different from Auer bodies. The appearance and staining characteristics on light microscopy and electron microscopy resemble the cases of acute myeloid leukemia described by Wolf et al. [5] and Felman et al. [6]. The inclusions in the patients in their cases and ours were stained with PAS. Inclusions in CMML with Double Minute Chromosomes and MYC Amplification
1 Vardiman JW, Thiele J, Arber DA, Brunning RD, Borowitz MJ, Porwit A, Harris NL, Le Beau MM, Hellström-Lindberg E, Tefferi A, Bloomfield CD: The 2008 revision of the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia: rationale and important changes. Blood 2009; 114: 937– 951. 2 Parikh SA, Tefferi A: Chronic myelomonocytic leukemia: 2012 update on diagnosis, risk stratification, and management. Am J Hematol 2012;87:610–619. 3 Thomas L, Stamberg J, Gojo I, Ning Y, Rapoport AP: Double minute chromosomes in monoblastic (M5) and myeloblastic (M2) acute myeloid leukemia: two case reports and a review of literature. Am J Hematol 2004;77: 55–61. 4 Karasawa M, Okamoto K, Maehara T, Tsukamoto N, Morita K, Naruse T, Omine M: Detection of c-myc oncogene amplification in a CML blastic phase patient with double minute chromosomes. Leuk Res 1996;20:85– 91.
Acta Haematol 2014;132:68–72 DOI: 10.1159/000355640
71
5 Wolf DJ, Fialk MA, Mouradian J, Gottfried EL, Pasmantier MW: Unusual intracytoplasmic inclusions in acute myeloblastic leukemia. Am J Hematol 1980;9:413–420. 6 Felman P, Morel D, Bryon PA, Espinouse D, Coeur P: Intra-cytoplasmic crystalline inclusions in acute myeloid leukemia: a rare event. Scand J Haematol 1986;36:520–524. 7 Michalová K, Cermák J, Brezinová J, Zemanová Z: Double minute chromosomes in a patient with myelodysplastic syndrome transforming into acute myeloid leukemia. Cancer Genet Cytogenet 1999;109:76–78.
72
8 The Fourth International Workshop on Chromosomes in Leukemia: a prospective study of acute nonlymphocytic leukemia. Chicago, Ill., USA, September 2–7, 1982. Cancer Genet Cytogenet 1984;11:249–360. 9 Bruckert P, Kappler R, Scherthan H, Link H, Hagmann F, Zankl H: Double minutes and cMYC amplification in acute myelogenous leukemia: are they prognostic factors? Cancer Genet Cytogenet 2000;120:73–79.
Acta Haematol 2014;132:68–72 DOI: 10.1159/000355640
10 Movafagh A, Mirfakhraei R, MousaviJarrahi A: Frequent incidence of double minute chromosomes in cancers, with special up-to-date reference to leukemia. Asian Pac J Cancer Prev 2011; 12: 3453– 3456. 11 Adès L, Sekeres MA, Wolfromm A, Teichman ML, Tiu RV, Itzykson R, Maciejewski JP, Dreyfus F, List AF, Fenaux P, Komrokji RS: Predictive factors of response and survival among chronic myelomonocytic leukemia patients treated with azacitidine. Leuk Res 2013;37:609–613.
Miyazaki/Suzuki
Copyright: S. Karger AG, Basel 2014. Reproduced with the permission of S. Karger AG, Basel. Further reproduction or distribution (electronic or otherwise) is prohibited without permission from the copyright holder.
Received: June 20, 2013 Accepted after revision: September 14, 2013 Published online: January 24, 2014
Unusual Intracytoplasmic Crystalline Inclusions in Chronic Myelomonocytic Leukemia with Double Minute Chromosomes and MYC Amplification: A Rare Case Kanji Miyazaki Kenshi Suzuki Department of Hematology, Japanese Red Cross Medical Center, Tokyo, Japan
Key Words Chronic myelomonocytic leukemia · Double minute chromosomes · Intracytoplasmic inclusions
Abstract Chronic myelomonocytic leukemia (CMML) is a clonal hematological disease characterized by the presence of peripheral blood monocytosis and bone marrow dysplasia. Double minute chromosomes (dmin) are rare and intracytoplasmic crystalline inclusions are very rare in hematologic malignancies. We present a case of CMML with dmin and unusual intracytoplasmic crystalline inclusions. To our knowledge, no such case has previously been reported. © 2014 S. Karger AG, Basel
Introduction
Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic stem cell disorder. CMML is characterized by the presence of an absolute monocytosis (>1 × © 2014 S. Karger AG, Basel 0001–5792/14/1321–0068$39.50/0 E-Mail [email protected] www.karger.com/aha
109/l) in the peripheral blood and the presence of myelodysplastic and myeloproliferative features in the bone marrow, absence of the Philadelphia chromosome and the BCR-ABL1 fusion gene, absence of rearrangement of platelet-derived growth factors A (PDGFRA) and B (PDGFRB), 90%) infiltrated by myeloperoxidase positive cells without any signs of myelofibrosis and crystal-like inclusions were very scarce (fig. 2). On electron microscopy, well-demarcated rectangular intracytoplasmic crystal-like inclusions were seen. The inclusions were electron-dense, and were enclosed in intracytoplasmic membranes (fig. 3). The inclusions had 3-nm, periodic, lattice-like structures. Round inclusions were also electron-dense and were enclosed in cytoplasmic membranes, suggesting that these round inclusions are the same as rectangular ones and that these small electron-
dense inclusions might fuse together to form rectangular electrondense crystalline inclusions. Chromosomal analysis of 30 metaphases showed the presence of deletion 20q and dmin. The karyotype was described as 46, XY, del (20)(q11q13) [7]/46, XY, del (20)(q11q13), 1–10 dmin [16]/46, XY [5] (fig. 4). We performed fluorescence in situ hybridization (FISH) using an MYC/IgH probe set to further characterize the dmin. Deletion of the MYC gene on the #8 chromosome and amplification of the MYC gene in the form of dmin were confirmed (fig. 5). No BCR/ABL1 rearrangement was detectable in molecular genetic analysis. The patient was treated with azacitidine (75 mg/m2/day for 7 days, every 4 weeks) based on a diagnosis of CMML-2. After
Inclusions in CMML with Double Minute Chromosomes and MYC Amplification
Acta Haematol 2014;132:68–72 DOI: 10.1159/000355640
Fig. 2. Bone marrow biopsy. Myeloperoxidase. Bone marrow
biopsy revealed hypercellularity (>90%) infiltrated by myeloperoxidase positive cells. Crystal-like inclusions were very scarce.
69
a
b
c
d
e
f
Fig. 3. Electron-microscopic appearance of intracytoplasmic inclusions. a A rectangular electron-dense inclusion in a granulocyte. b, c The inclusion is enclosed in intracytoplasmic membranes. d Irregular shaped inclusions existed. e, f Square and round inclusions. They were also electron-dense.
1
6
Fig. 4. Representative karyotype demon-
strating the presence of dmin and the deletion of 20q.
70
Acta Haematol 2014;132:68–72 DOI: 10.1159/000355640
2
7
3
9
8
13
14
19
20
4
15
21
5
11
10
16
22
dmin
Miyazaki/Suzuki
12
17
18
X
Y
MYC
IgH
a IgH MYC (dmin) MYC (dmin)
MYC (dmin)
MYC (dmin) MYC (dmin) MYC
MYC (dmin)
IgH MYC (dmin)
b
In all 3 cases, inclusions were absent in band forms and neutrophils, and absent in the peripheral blood. Two explanations are possible: the inclusions were dissolved or had been extruded from these cells, or the presence of the inclusions did not permit differentiation beyond the metamyelocyte stage. The fact that the inclusions were enclosed in intracytoplasmic membranes, which was not observed in the previous reports, suggests that these inclusions are an accumulation of protein material in the endoplasmic reticulum caused by abnormal metabolism of leukemic cells. In our case, both dmin and MYC amplification were observed, unlike the cases of Wolf et al. [5] and Felman et al. [6], and it seems the formation of intracytoplasmic crystalline inclusions is not related to MYC amplification. Double minutes are rare in hematologic malignancies and are associated with poor prognosis [3, 8, 9]. Almost all cases are acute leukemia. Some cases of myelodysplastic syndromes have been reported [7]. Usually dmin of the hematologic malignancy carry the MYC or KMT2A gene [10]. Our CMML-2 patient relapsed after the 6 cycles of azacitidine. The leukemic cells became resistant to cytotoxic chemotherapy. Although azacitidine is a reasonable treatment option for CMML [2, 11], CMML patients with dmin may be regarded as poor-risk patients and therefore considered suitable candidates for allogeneic stem cell transplantation.
Fig. 5. Interphase (a) and metaphase (b) FISH, showing numerous
extra copies of the MYC gene (red) as dmin.
References 2 cycles, the patient achieved complete remission (CR), according to the modified International Working Group criteria. After 6 cycles, the patient relapsed into CMML-2, underwent induction therapy (idarubicin and cytarabine) and died at 6 months due to uncontrolled CMML-2 from the CMML-2 diagnosis.
Discussion
The intracytoplasmic crystalline inclusions in this patient were distinctly different from Auer bodies. The appearance and staining characteristics on light microscopy and electron microscopy resemble the cases of acute myeloid leukemia described by Wolf et al. [5] and Felman et al. [6]. The inclusions in the patients in their cases and ours were stained with PAS. Inclusions in CMML with Double Minute Chromosomes and MYC Amplification
1 Vardiman JW, Thiele J, Arber DA, Brunning RD, Borowitz MJ, Porwit A, Harris NL, Le Beau MM, Hellström-Lindberg E, Tefferi A, Bloomfield CD: The 2008 revision of the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia: rationale and important changes. Blood 2009; 114: 937– 951. 2 Parikh SA, Tefferi A: Chronic myelomonocytic leukemia: 2012 update on diagnosis, risk stratification, and management. Am J Hematol 2012;87:610–619. 3 Thomas L, Stamberg J, Gojo I, Ning Y, Rapoport AP: Double minute chromosomes in monoblastic (M5) and myeloblastic (M2) acute myeloid leukemia: two case reports and a review of literature. Am J Hematol 2004;77: 55–61. 4 Karasawa M, Okamoto K, Maehara T, Tsukamoto N, Morita K, Naruse T, Omine M: Detection of c-myc oncogene amplification in a CML blastic phase patient with double minute chromosomes. Leuk Res 1996;20:85– 91.
Acta Haematol 2014;132:68–72 DOI: 10.1159/000355640
71
5 Wolf DJ, Fialk MA, Mouradian J, Gottfried EL, Pasmantier MW: Unusual intracytoplasmic inclusions in acute myeloblastic leukemia. Am J Hematol 1980;9:413–420. 6 Felman P, Morel D, Bryon PA, Espinouse D, Coeur P: Intra-cytoplasmic crystalline inclusions in acute myeloid leukemia: a rare event. Scand J Haematol 1986;36:520–524. 7 Michalová K, Cermák J, Brezinová J, Zemanová Z: Double minute chromosomes in a patient with myelodysplastic syndrome transforming into acute myeloid leukemia. Cancer Genet Cytogenet 1999;109:76–78.
72
8 The Fourth International Workshop on Chromosomes in Leukemia: a prospective study of acute nonlymphocytic leukemia. Chicago, Ill., USA, September 2–7, 1982. Cancer Genet Cytogenet 1984;11:249–360. 9 Bruckert P, Kappler R, Scherthan H, Link H, Hagmann F, Zankl H: Double minutes and cMYC amplification in acute myelogenous leukemia: are they prognostic factors? Cancer Genet Cytogenet 2000;120:73–79.
Acta Haematol 2014;132:68–72 DOI: 10.1159/000355640
10 Movafagh A, Mirfakhraei R, MousaviJarrahi A: Frequent incidence of double minute chromosomes in cancers, with special up-to-date reference to leukemia. Asian Pac J Cancer Prev 2011; 12: 3453– 3456. 11 Adès L, Sekeres MA, Wolfromm A, Teichman ML, Tiu RV, Itzykson R, Maciejewski JP, Dreyfus F, List AF, Fenaux P, Komrokji RS: Predictive factors of response and survival among chronic myelomonocytic leukemia patients treated with azacitidine. Leuk Res 2013;37:609–613.
Miyazaki/Suzuki
Copyright: S. Karger AG, Basel 2014. Reproduced with the permission of S. Karger AG, Basel. Further reproduction or distribution (electronic or otherwise) is prohibited without permission from the copyright holder.
