Cytogenetic abnormalities in the leukemic phase of non-Hodgkin lymphoma

ELSEVIER

Cytogenetic Abnormalities in the Leukemic Phase of Non-Hodgkin Lymphoma M. T. Khokhar, V. Brito-Babapulle, E. Matutes, and D. Catovsky

ABSTRACT: We have carried out chromosome analysis in a series of 16 non-Hodgkin L y m p h o m a (NHL) cases in leukemic phase. The diagnoses in these patients based on histology and immunologic markers were as follows: follicular lymphoma (FL), 3 cases; mantle cell lymphoma (Mc), 4 cases; lymphoplasmacytic l y m p h o m a (LPL), 8 cases, and large cell lymphoma, I case. We have shown that the t(14;18)., t(11;14), and trisomy 12 retained their subtype association with FL, Mc, and LPL, respectively, as in their nonleukemic counterparts with one case of FL showing t(1;19)(q23;p13). Among the four LPL cases without trisomy 12, one case each showed t(12;14)(q13;q32), trisomy 14, t(1;3)(p34;q21), and del(3)(q21). The t(1;19) and t(12;14) m a y represent rare events in FL and LPL, respectively, and may be uniquely associated with the leukemic phase. The breakpoint 14q32 was the most common single breakpoint involved, sometimes involving both chromosome 14 homologues depicting its association with primary and secondary genetic events in the disease progression. In addition to the main abnormalities, we have shown additional complex abnormalities in 14 of 16 cases. Among these, chromosome 3 was the most commonly involved, affecting the short or long arm or the whole chromosome; 5 of the 16 cases involved breakpoint 3q21. The high incidence of additional abnormalities in these NHL in leukemic phase suggest an association with the development of leukemia and progression of the disease.

INTRODUCTION The development of a leukemic phase in non-Hodgkin lymphoma (NHL}, often poses diagnostic problems in particular if there is no information on the underlying histology. It is not clear why in such cases of NHL the disease progresses with leukemia whilst in a majority it does not. If the patient presents with a high lymphocyte count the leukemic phase of both follicular (FL} and mantle cell {Mc} lymphoma could resemble and be confused with chronic lymphocytic leukemia [CLL). The differences in clinical and prognostic features between these disorders underlines the need for a more precise differential diagnosis between them. Well characterized differences in histology, peripheral blood morphology and immunophenotypes have contributed to the separation of these B-cell disorders [1, 2]. However, diagnostic problems still persist in some of these lymphoma/leukemia syndromes. The known recurring chromosome translocations, t(14;18) (q32;q21) and t(8;14}(q24;q32), including its variants t(2;8) From the Academic Department of Hematology und Cytogenetics, Institutes of Cancer Research and Royal Marsden Hospital, Sutton and London, U.K. Address reprint requests to: Dr. M. Tariq Khokhar, Academic Department of Hematology and Cytogenetics, Institute of Cancer Research and Royal Marsden Hospital, Block F, 15-CotswoldRoad, Belmont Sutton, Surrey SM2 5NG, U.K. Received March 23, 1994; accepted December 23, 1994.

Cancer Genet Cytogenet 83:18-24 (1995) © Elsevier Science Inc., 1995 655 Avenue of the Americas, New York, NY 10010

or t(8;22) and t(11;14)(q13;q32), have shown a distinct subtype association with FL, Burkitt lymphoma (BL), and Mc lymphoma, respectively [3-8]. Trisomy 12 is a characteristic feature of CLL and has also been reported in small lymphocytic and lymphoplasmacytic lymphoma {LPL) [9-11]. Southern blot analysis with DNA probes for the protooncogenes BCL-2 and BCL-1/PBAD-1, located on the breakpoints 18q21 and 11q13, respectively, have complemented the evidence of a strong association between these translocations and subtypes of NHL [12, 13]. There is little information on the cytogenetic characteristics of NHL during the leukemic phase. This scanty information contrasts with the large number of reports on cytogenetic studies in NHL mainly correlating the histologic subtypes with specific karyotypic abnormalities [3, 4, 7, 14-17]. The t(14;18} observed in 85% cases of FL has been shown to be associated with del(13}(q32) in all the four c a s e s evolving with leukemia [3]. We report here the cytogenetic characteristics in a series of 16 cases of NHL corresponding histologically to FL, Mc, LPL, and large cell NHL that presented in leukemic phase. We have shown that the association of the t(14;18), t(11;14), and trisomy 12 with FL, Mc, and LPL subtypes of NHL, respectively, is retained in their leukemic counterparts. In addition, we describe in the majority several additional chromosomal abnormalities, some of which may be uniquely associated with the leukemic phase.

0165-4608/95/$9.50 SSDI 0165-4608(04)0030S-X

Cytogenetics in the Leukemic Phase of NHL

19

in 12 cases, in bone marrow in 3 cases, and in spleen in 1 case. Cultures of about 2 x 10e cells were set up in 10 mL of RPMI m e d i u m s u p p l e m e n t e d w i t h 20% fetal calf serum. Th e cells were grown as unstimulated or stimulated cultures w i t h mitogens: p h y t o h e m a g g l u t i n i n (PHA), 1:100 (Gibco); protein A (PA), 10 ttg/mL (Pharmacia); pokeweed mi t oge n (PWM), 1:100 (Gibco); interleukin 2 (IL2), 20 units/mL, and t u m o u r p r o m o t i n g agent 12-O-tetradecanoylphorbol-13 acetate (TPA), 0.05 ~tg/mL (Sigma). Cultures were incubated at 37°C for short-term (2, 24, 48, and 72 h) or long-term (5 or 7 days) periods and harvested after exposure to Colcemid for 50-60 min. Air-dried slide preparations were aged 3-5 days at 37~C and G-banded with Giemsa stain. The karyotypes were defined according to the International System for H u m a n Cytogenetic Nomenclature [181; the rearrangements were regarded as clonal if at least two cells carried the same translocation or showed gain of a chromosome.

MATERIALS AND METHODS

Patients The cytogenetic analysis was ascertained in a series of 16 cases treated at the Royal M a r s d e n Hospital between 1988 and 1992. The tissue diagnosis in these cases (except in cases 8 and 11) was obtained from bone marrow, l y m p h node, or spleen. These diagnoses were as follows: 3 cases of FL, 4 cases of Mc l y m p h o m a , 8 cases of LPL, and I case of large cell NHL. Th e m e a n age of the patients was 58 years, w i t h a range of 31 to 71 years; there were 12 males and 4 females (male-to-female ratio, 3:1). All the patients presented in leukemic phase, w i t h over 65% of the total WBC c o m p r i s i n g lymphocytes (except case 16, w i t h 40% lymphocytes). The cells in peripheral blood were morphologically mature, consistent w i t h the low to intermediate grade histology, except in case 5 wh ere the patient had an aggressive leukemic phase w i t h less mature cells and features suggestive of transformation. Th e m e a n WBC count was 64 x 109 /L, w i t h a range of 10 to 257 x 109/L, w h i l e m e a n of the absolute lymphocyte count was 55 x 109/L, w i t h a range of 3.7 to 244 x 109/L (Table 1).

RESULTS

Immunophenotype Features Th e i m m u n o p h e n o t y p i n g marker analysis of the leukemic cells showed p r e d o m i n a n t l y a m o n o c l o n a l B-cell proliferation (Table 1) in all the Cases w i t h characteristic differences from classic CLL (weak SmIg, CD10 - , CD5 +, CD23 +, weak or negative FMC7 or CD22). Most cases had strong density of SmIg; FMC7 or m e m b r a n e CD22 were positive in all the cases; half of t h e m expressed CD23 in a proportion of cells, and only six were CD5 positive (1FL, 2Mc, and 3LPL). All the cases were positive w i t h at least one of the B-cell antigens employed, i.e., CD19, CD37, or HLA-DR.

I m m u n o l o g i c Markers Marker studies were performed in circulating cells in all cases. M o n o n u c l e a r cells separated from peripheral blood were tested either by indirect i m m u n o f l u o r e s c e n c e in cell suspensions or by the alkaline phosphatase anti-alkaline phosphatase (APAAP) m e t h o d on fixed cytospin slides. The m o n o c l o n a l antibodies employed were CD2, CD3, CD5, FMCZ CD10, CD19, CD22, CD23, CD38, and HLA-DR; polyclonal antibodies were used against kappa and lambda light chains (SmIg).

Cytogenetic Findings The chromosome abnormalities observed in 16 cases are summarized in Table 2. The abnormalities were d i v i d ed into two classes: a) m a i n abnormalities and b) additional abnormali-

Cytogenetic Methods C h r o m o s o m e analysis was performed with peripheral blood

Table 1

Clinical data SmIg

% of positive cells

Case no.

Diagnosis

Age/sex

wbc x 10/L

% PBL

K

k

CD5

FMC7

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

FL FL FL Mc Mc Mc Mc LPL LPL LPL LPL LPL LPL LPL LPL LC

59/M 31/M 56/M 64/M 59/M

60 21 257 46 180 24 20 ND 10 29 163 35 18 26 43 31

75 80 95 85 65 65 87 ND 76 65 90 83 92 81 96 40

83 0 + 74 68 1 65 17 53 81 1 55 1 82 1 19

1 96 32 1 78 7 1 8 3 79 5 74 1 92 44

5 14 ND 38 10 76 59 68 61 ND 6 11 9 38 ND 16

64 77 ND 38 66 76 63 11 73 69 71 62 1 46 9 47

71/M

53/M 68/M 49/M 64/F 64/F 56/M 54/M 68/F 52/M 67/F

* C D 2 2 C D 2 3 CD10 43 25 ND 51 17 57 47 84 64 55 82 ND 87 34 42 12

55 25 ND 17 11 42 11 92 ND 25 12 ND 13 25 ND 9

50 34 ND 45 31 10 4 9 ND 66 9 5 42 ND 43 34

Abbreviations: FL, Follicular lymphoma; Mc, mantle cell lymphoma; LPL, lymphoplasmacytic;NHL, non-Hodgkinlymphoma; LC,

large cell lymphoma; M, male; F, female, ND, data not available; PBL, PB lymphocytes. * Membrane expression.

20

M . T . Khokhar et al.

ties. The main abnormalities were the ones seen in a majority of the abnormal cells or k n o w n to be associated with a particular subtype of the NHL. The most frequent breakpoint involved chromosome 14q32, the site of i m m u n o g l o b u l i n heavy chain gene (IgH) and was seen i n 7 cases as the m a i n translocation a n d i n 5 cases as a n additional abnormality. The m a i n abnormalities showed a degree of association with the u n d e r l y i n g diagnosis, although a few exceptions were apparent. Tmnslocation (14;18) was detected in 2/3 cases of FL, t(11;14) in 4/4 cases of Mc lymphoma, and trisomy 12 or t(12;14)(q13;q32) was the m a i n feature of 5 of 8 cases of LPL and was also seen in the large cell lymphoma. Figures 1, 2, and 3 show a representative karyotype each from FL, Mc, and LPL subtypes, respectively. In a case of FL (no. 3), the t(1;19)(q23;p13) was detected. In this case the histology of the l y m p h node had shown p r e d o m i n a n t l y the presence of small cleaved cells with sparsely spaced large cells. No t(14;18) was detectable cytogenetically. Of the three LPL cases w i t h o u t involvement of chromosome 12, trisomy 14 was detected in one case (no. 8), t(1;3)(p34;q21) in one case (no. 10), and del(3)(p21) i n another case (no. 15). Trisomy 12 was demonstrated i n case no. 16 with large cell NHL. There was no previous documented evidence of a low grade l y m p h o m a i n this case. A high i n c i d e n c e of additional abnormalities coexisted with the m a i n abnormalities and were detected in 14 of the 16 cases studied. In 10 of these, all the abnormal metaphases carried both m a i n a n d additional abnormalities. Chromosome 3 was the most c o m m o n l y rearranged among these abnormalities, present in 9 cases, with involvement of the short or long arm or as a trisomy 3. In 5 cases, the breakpoint was 3q21. Other abnormalities observed were: chromosome I in

Table

2

Case no.

4 cases with lq21-25 region or the whole of q arm being involved, and del 6q21-25 i n 2 of the 4 cases of FL and one case of LPL. The 8q24 abnormality was detected i n 3 cases (nos. 4, 5, and 16). The 11q13 was detected as dup(11)(q13) i n two cases (nos. 3 a n d 5) and as trp(11)(q13) i n two cases (nos. 5 a n d 7) of Mc l y m p h o m a with the additional 11q13 translocated to partners other than 14q32 in t(11;14). In case no. 5 the additional 11q13 i n one sideline was involved i n t(8;11)(q24;q13), while i n another in t{8;11)(p21;q13) a n d i n case no, 7 the 11q13 was translocated in t(11;21)(q13;p?). Chromosome 18 was involved i n 3 cases of LPL: i n case no. 10 with t(2 ;18)(q21;q21), in case no. 12 as trisomy 18, and i n case no. 16 both as trisomy a n d tetrasomy 18. DISCUSSION We have characterized the cytogenetic findings i n a series of 16 cases of B-cell NHL presenting i n leukemic phase, a manifestation of the lymphomaJleukemia interphase seen during the evolution of B-cell lymphomas. We have confirmed that the m a i n recurring chromosome translocations, t(14;18), t(11;14), and trisomy 12, were largely associated with FL, Mc, and LPL, respectively [3, 4, Z 14, 19, 20]. This subtype association was retained in the leukemic phase of the same types of NHL. This f i n d i n g emphasizes the diagnostic importance of these chromosome markers for a precise disease characterization of the heterogeneous group of NHL. These chromosome markers should complement and aid the histologic classification for this group of cases, i n particular those where the diagnosis is difficult and resembles CLL [21]. A chromosome translocation involving the breakpoint 14q32 was observed in 9 of the 16 cases w h i c h correlate with

Cytogenetic data Tissue

Cells N/A

Main recurring abnormalities

1 2 3

PB PB PB

43/18 3/8 9/71

t(14;18)(q32;q21) t(14;18)(q32;q21) t(1;19)(q23;p13)

4 5

BM PB

8/4 6/8

t(11;14)(q13;q32) t(11;14)(q13;q32)

6 7

BM PB

0/7 8/4

t(11;14)(q13;q32) t(11;14)(q13;q32)

8

9

PB PB

16/5 20/12

+ 14 t(12;14)(q13;q32)

10

PB

0/10

11 12 13 14 15 16

PB SP PB PB PB BM

40/12 2/15 7/3 0/5 9/7 15/20

t(1;3)(p34;q21) + 12 + 12 + 12 + 12 del(3)(p21) + 12

Additional chromosomal abnormalities t(3;13)(q21;q32),del(6}(q21) t(3;8;9){q21;p21;p22),del(6)(q25) + del(3)(p21),dup(11)(q13q25),der(19)t(1;19) (q?;p13) del(8)(q24) del(3)(p21),der(8)t(8;11)(q24;q13),t(8;11)(p12;q13), dup(11)(q13q25) der(1)t(1;?),add(14)(q32),del(13) der(2)t(2;?)(q?;?),t(4;5)(q21;p15),del(3}(?),trp(11) (q13q),t(11;21)(q13;p?),der(17)t(17;?11) none t(1;4)(q21;q32),der(14)t(1;14)(q21;q32),der(15) t(1;15)(q21;p12),der(3)t(3;3)(p25;q21)dup(3) (q21q29) t(2; 18)(q21;q21),del(3)(q21),t(4;14)(p14;q32), t(4;19)(q21;p13),del(13)(q12) add(14)(q32) - Y , + 18 +3 none del(1)(q21-q25),der(2)t(2;?),del(6)(q23) + 3, + 4,der(6)ty(6;8)(p21;q32),dup(6)(p21p?), der(14)t(6;14)(p21;qU2)add(14)(p?), + 18, + 18

Abbreviations: PB, peripheral blood; BM, bone marrow; SP, spleen; N, no. of normal cells; A, no. of abnormal cells.

No. of cells 8 4 71 4 8 7 4 O 12

10 4 15 3 0 2 19

Cytogenetics in the Leukemic Phase of NHL

21

(

i

l 4

z

II

II

t

|4

| l

9

m

||

lz

m

--

8

B

J Figure 1

Case no. 3 FL;47,XY,t(1;19)(q23;p13),+ del(3){p21),dup(11)(q13;q25), + der(19]t(1;19)(q?;p13).

the p r e d o m i n a n t B-cell nature of the diseases u n d e r study a n d the localization a n d rearrangement of the IgH gene at this locus. In 3 cases [nos. 6, 9, a n d 16), rearrangements involving 14q32 were present in both homologues. The involve-

!ii

ii¸¸I iiiii:

merit of both 14(t32 loci in the p a i r of t(14;18) a n d t(8;14) as p r i m a r y a n d s e c o n d a r y events has been reported among patients w i t h FL associated w i t h t u m o r progression [22], from low grade l y m p h o m a to Burkitt type lymphoblastic leukemia.

....

Figure 2

Case no. 5 Mc lymphoma; 46,XY,der(8)t(8;11)(q24;q13),t(11;14)(q13;q32).

!!

~ i i¸i

22

M . T . Khokhar et al.

|9

Figure 3 Case no. 9 LPL; 46~Y~t~1;4~q21;q35~der~3~t~3;3~q2~;p25~dup~3~q2~q29~t~12;14~q13;q32~der~4~t(1;14) (q21;q32),der(15)t(1;15)(q21;p12).

Our main observation was a high incidence of additional chromosome abnormalities in this series involving chromosomes 1, 3, 6q, 8q24, and 11q13. These abnormalities have been shown by Heim and Mitelman [23, 24] to be associated with c o m m o n ALL or pre-B-cell ALL. The occurrence of these abnormalities in the cases described here along with the main abnormalities probably results from karyotypic evolution associated with leukemic transformation. This may be analogous to the transition to blast crisis associated with additional abnormalities superimposed on t(9; 22) in chronic myeloid leukemia [25]. Evolution by the appearance of secondary abnormalities of lq such as multisomy lq (seen in case nos. 3 and 9) has been suggested to be a p h e n o m e n o n in B-ALL promoting tumor cell proliferation [26]. Moreover, the occurrence of trisomy 3 and 6q abnormalities in FL has been correlated with the histologically more advanced subtypes of NHL [3, 17]. This is the first cytogenetic study in a series of NI-IL in w h i c h all the cases presented in leukemic phase and the keryotypes were obtained mainly from the circulating cells. Criel et al. [27] reported cytogenetic findings in the leukemic phase of Mc lymphoma. In this series, the t(11;14) was observed in all 12 cases, with additional abnormalities of chromosome 3 recorded in 2, of chromosome 6 in 5, and of chromosome 1 in 3 cases. This study and ours suggest a role for these secondary abnormalities in the leukemic transformation of NHL. The presence of additional abnormalities only in some of the cells in 5 cases {nos. 1, 2, 11, 15, and 16) supports the view that these secondary events represent karyotypic evolution associated with disease progression and leukemic spread. The combination of primary and secondary events

may have predictive value w h e n examined in relation to the change in disease status [24]. The structural and numerical abnormalities of chromosome 3 detected in 9 cases demonstrate a possible predominant role played by chromosome 3 in the leukemic evolution of NHL. Cases with abnormalities of chromosome 3q21-25 in NHL have been shown to correlate with bulky disease [14, 15]; 5 of our cases (nos. 1, 2, 5, 9, and 10) had breakpoints at 3q21. A recent molecular study of the breakpoint 3q27 has shown it to be the location of the BCL-6 gene, which may be important in the genesis of certain B-cell NHL through deregulation of protooncogenes associated with cell proliferation [281. The findings of t(1;19)(q23;p13) in FL (case no. 3) and t(12 ;14)(q13;(t32) detected in LPL (case no. 9) were unexpected. The t(1;19) is a known characteristic of pre-B ALL [29]. The emergence of t(1;19) may have been a secondary event during disease progression from a low grade follicular histology to an aggressive leukemic manifestation, with a very high WBC (257 x 109/L). This abnormality was present in all abnormal metaphases and no t(14;18) was demonstrated. It is possible that this abnormality may represent a rare event in FL associated with leukemia. The t(12;14)(q13;q32) in a case of LPL has not been previously reported in either lymphoma or leukemia as far as we are aware [24, 30]. The only other example was in a case of myelodysplastic syndrome transforming to acute myeloid leukemia of the FAB MSa type [31]. The presence of t(12;14) together with t(1;14)(q21;q32) in patient no.9 suggests a karyotypic evolution also in LPL associated with progression to leukemia. In case 5, t(11;14)(q13;q32) was detected together with

Cytogenetics in the Leukemic Phase of NHL t(8;11)(q24;q13), for the protooncogenes bcl-1/Pmd-1 a n d c-myc are located at 11q13 and 8q24, respectively [32]. Simultaneous rearrangement of both BCL-2 a n d c-MYC has been suggested to interfere w i t h p r o g r a m m e d cell death [33]. The observation in this case of rearrangement of 11q13 (bcl-1) [34] a n d p o s s i b l y 8q24 (c-MYC) may be analogous to bcl-2 and c-myc a n d warrants further investigation. The presence of extra copies of c h r o m o s o m e 11q13 as dup(ll)(q13) or trp(11) (q13) in Mc l y m p h o m a (cases nos. 5 and 7) may result from clonal e x p a n s i o n a n d e m p h a s i z e s the i m p o r t a n c e of rearrangements at this locus. The role of a d d i t i o n a l breakpoints translocated to 11q13 other than in t(11;14) may represent seco n d a r y genetic events involving rearrangements of loci for new putative oncogenes, w h i c h may be important in the leukemic manifestation of Mc l y m p h o m a [35]. Trisomy 12 was found in 4 of 8 LPL cases, w i t h another carrying t(12;14)(q13;q32). In case 11, all the abnormal cells showed trisomy 12 w i t h some of t h e m also containing add(14). This suggests that trisomy 12 was an earlier event t h a n the subsequent leukemic change affecting the 14q32 (IgH) locus. However, w h e n trisomy 12 is seen w i t h t(14;18), it has been regarded as a secondary change with disease evolution from a low grade FL to a h i g h grade leukemic form [3]. Trisomy 12 has also been d o c u m e n t e d in small l y m p h o cytic l y m p h o m a as a p r i m a r y event and karyotypic evolution w i t h t(18;22)(q21;q11) involving the l a m b d a light c h a i n a n d BCL-2 [36]. Trisomy 12 is k n o w n to be associated w i t h CLL [37]. A study by us [9] of 183 CLL cases investigated by FISH detected trisomy 12 in 21 (11.5%) of these cases. The fact that the trisomy 12 is associated w i t h CLL and LPL cases supports the suggested lineage r e l a t i o n s h i p between lymphocytic l y m p h o m a a n d B-cell CLL [38]. Case 16 was of special interest because the diagnosis was large B-cell NHL presenting in leukemic phase, a rare event [39]. The karyotype showed a complex a n d variable clone w i t h several sidelines, w i t h both 14q32 loci being rearranged, as well as trisomy 12. In particular, 1 of the 20 cells a n a l y z e d showed o n l y trisomy 12 a n d 18, suggesting that trisomy 12 or 18 represented an earlier low grade NHL (LPL- or CLL-like) transforming into large cell l y m p h o m a . M o l e c u l a r analysis of c h r o m o s o m e rearrangements have resulted in identification of several genes w h i c h are directly i m p l i c a t e d in the b i o l o g y of NHL. However, it is o n l y possible w i t h cytogenetic studies to identify the presence of additional events w h i c h could lead to the further characterization of these genetic transpositions. Studies w i t h c h r o m o s o m e p a i n t i n g a n d in situ h y b r i d i z a t i o n w i t h breakpoint-specific probes may h e l p elucidate the nature of c o m p l e x translocations a n d the genes involved in the s e c o n d a r y events. A sequential s t u d y in these cases may also establish the relative importance of these rearrangements at different stages of the l y m p h o m a f l e u k e m i a d e v e l o p m e n t a n d define in p a r t i c u l a r the role of the a d d i t i o n a l abnormalities d e s c r i b e d here in the leukemic evolution. This work was supported by the Cancer Research Campaign. I am grateful to Dr. Toon Min and Mr. J. Swansbury for many helpful discussions. We are grateful to Dr. D. Cunningham, other members of the lymphoma unit, and to clinicians from other hospitals who provided us with some of the cases, and Drs. K. MacLennan and J. Sloane for reviewing the histology of these reported cases. Last,

23 but not least, my appreciation and thanks to Miss Sophia Tariq and Miss Wanda Malinowsky for their help in preparation of this manuscript. REFERENCES

1. Melo TV, Robinson DSF, de Oliveira MP, Thompson IW, Lampert IA, Ng JP, Galton DAG,Cstovsky D (1988): Morphology and immunology of circulating cells in leukaemic phase of follicular lymphoma. J Clin Pathol 41:951-959. 2. Pombo de Oliveira MS, Jaffe ES, Catovsky D (1969): Leukaemic phase of mantle zone [intermediate) lymphoma: its characterization in 11 cases. J Clin Pathol 42:962-972. 3. Yunis ~, Frizzera G, Oken MM, McKenna J, Theologides A, Arnesen M (1987): Multiple recurrent genomic defects in follicular lymphoma. New Engl J Med 316:79-84. 4. Bloomfield CD, Arthur DC, Frizzera G, Levine EG, Peterson BA, Gajl-Peczalska I~ (1983): Nonrandom chromosome abnormalities in lymphoma. Cancer Res 43:2975-2984. 5. Levine EJ, Arthur DC, Frizzera G, Peterson BA, Hurd DD, Bloomfield CD (1985): There are differences in cytogenetic abnormalities among histologic subtypes of the non-Hodgkiffs lymphomas. Blood 66:1414-1422. 6. The Fifth International Workshop on Chromosomes in Leukamia-Lymphoma (1987): Correlation of chromosome abnormalities with histologic and immunologic characteristics in nonHodgkin's lymphoma and adult T cell leukemia-lymphoma. Blood 70:1554-1564. 7. Koduru PRK, Filippa DA, Richardson ME, Jhanwar SC, Chaganti SR, Koziner B, Clarkson BD, Lieberm•n PH, C h ~ n t i RSK (1987}: Cytogenetic and histologic correlations in malignant lymphoma. Blood 69:97-102. 8. Vandenberghe E, De Wolf-Peeters C, Van den Oord J, Wlodarska I, Delabie J, Stul M, Thomas J, Michaux J-L, Mecucci C, Cassiman J-J, Van den Berghe H (1991): Translocation (11;14): a cytogenetic anomaly associated with B-cell lymphomas of nonfollicle center cell lineage. J Clin Pathol 163:13-18. 9. Que TH, Garcia Marco J, Ellis J, Matutes E, Brito-Babapulle V, Boyle S, Catovsky D (1993): Trisomy 12 in chromic lymphocytic leukemia detected by fluorescence in situ hybridization: analysis by stage, immunophenotype and morphology. Blood 82:571-575. 10. Yunis II, Oken MM, Theologides A, Howe RB, Kaplan ME (1984): Recurrent chromosomal defects are found in most patients with non-Hodgkin's lymphoma. Cancer Genet Cytogenet 13:17-26. 11. Juliusson G and Gahrton G (1990): Chromosome aberrations in B-cell chronic lymphocytic leukemia. Pathogenetic and clinical implications. Cancer Genet Cytogenet 45:143-160. 12. Tsujimoto Y, Cossman J, Jaffe E, Croce CM (1985): Involvement of the bcl-2 gene in human follicular lymphoma. Science 228:1440-1443. 13. Rimokh R, Berger F, Comillet P, Wahbi K, Rouault J-P, Ffrench M, Byron P-A, Gadoux M, Gentilhomme O, Germain 13, Magaud J-P (1990): Break in the BCL1 locus is closely associated with intermediate lymphocytic lymphoma subtype. Genes Chrom Cancer 2:223-226. 14. Levine EG, ]uneja S, Arthur D, Garson OM, Machniki JL, Frizzera G, Ironside P, Cooper I, Hurd DD, Peterson BE), Mosel D, Bloomfield CD (1990): Sequential karyotypes in non-Hodgkin lymphoma: their nature and significance. Genes Chrom Cancer 1:270-280. 15. Schouten HC, Sanger GW, Weisenburger DD, Anderson J, Atmirage JO for the Nebraska Lymphoma Study Group (1990): Chromosomal abnormalities in untreated patients with non-Hodgkin's lymphoma: associations with histology, clinical characteristics and treatment outcome. Blood 75:1641-1847. 16. Offit K, Jhanwar SC, Ladanyi M, Filippa I ~ , Chaganti RSK (1991): Cytogenetic analysis of 434 consecutively ascertained

24

17.

18.

19.

20.

21. 22.

23. 24. 25. 26.

27.

26.

M . T . Khokhar et al. specimens of non-Hodgkin's lymphoma: correlations between recurrent aberrations, histology and exposure to cytotexic treatment. Genes Chrom Cancer 3:189-201. Richardson ME, Qnanguang C, Filippa DA, Offit K, Hamptom A, Koduru PRK, Janwar SC, Lieberman PH, Clarkson BD, Chaganti RSK (1987): Intermediate- to high-grade histology of lymphomas carrying t(14;16) is associated with additional nonrandom chromosome changes. Blood 70:444-447. ISCN 1991: Cancer Cytogenetics; Supplement to An International System for Human Cytogenetic Nomenclature, 1991. S. Karger, Basel. Yunis JJ, Oken MM, Kaplan ME, Ensrud KM, Howe R_R,Theologides A (1982): Distinctive chromosomal abnormalities in histologic subtypes of non-Hodgkin's lymphoma. N Engl J Med 307:1231-1236. Schouten HC, Sanger WG, Armitage JO (1991): Chromosomal abnormalities in malignant lymphoma and Hodgkin's disease. Leukemia and Lymphoma 5:93-100. Catovsky D, Foa R (1990): The Lymphoid Leukaemias, Butterworths, London. Brito-Babapulle V, Crawford A, Khokhar T, Laffan M, Matutes E, Fairhead S, Catovsky D (1991): Translocations t(14;18) and t(8;14) with rearranged bcl-2 and c-myc in a case presenting as B-ALL (L3). Leukemia 5:83-67. Heim S, Mitelman F (1967): Cancer cytogenetics. Alan R Liss, Inc. Mitelman F, Helm S {1992): Quantitative acute leukemia cytogenetics. Genes Chrom Cancer 5:57-66. Rowley JD (1963): Consistent chromosome abnormalities in human leukemia and lymphoma. Cancer Investigation 1:267-280. Morris CM, Fitzgerald PH, Neville MA, Wyld PJ, Beard ME (1994): Does multisomy of chromosome lq confer a proliferative advantage in B-cell acute lymphoblastic leukemia? Cancer 54:48-53. Criel A, Billiet J, Vandeberghe E, Van den Berghe H, Louwagie A, Hidajat M, Vanhoof A (1992): Leukaemic intermediate lymphocytic lymphomas: analysis of twelve cases diagnosed by morphology. Leukemia and Lymphoma 8:381-387. Baron WB, Nuciform G, McCabe N, Espinosa R, Le Beau MM, McKeithan TW (1993): Identification of the gene associated with the recurring chromosomal translocations t(3;14) (q27;q32) and

t(3;22)(q27;qll) in B-cell lymphomas. Pmc Natl A~ad Sci USA 90:5262-5266. 29. Carroll AJ, Crist WM, Parmley RT, Roper M, Cooper MD, Finley WH (1994): Pre-B cell leukemia associated with chromosome tmnslocation 1;19. Blood 63:721-724. 30. Mitelman F (1991): Catalog of Chromosome Aberrations in Cancer. Fourth Edition. Wiley-Liss. 31. Badia L, Alvarez MA, Palan F, Prieto F (1993): Translocation (12;14) (q13;q32) in myelodysplastic syndrome. Cancer Genet Cytogenet 65:76-78. 32. Raffeld M, Jaffe ES (1991): bcl-2, t(11;14) and mantle cell-derived lymphomas. Blood 76:259-263. 33. Evan GI, Wyllie AH, Gilbert CS, Littlewood TD, Land H, Brooks M, Waters CM, Penn LZ, Hancock DC (1992): Induction of apoptosis in fibroblasts by c-myc protein. Cell 69:119-128. 34. Jadayel D, Matutes E, Dyer MJS, Brito-Babapulle V, K_hokhar MT, Oscier DG, Catovsky D (1994): Splenic lymphoma with villous lymphocytes; analysis of BCL-1 rearrangements and expression of the cyclin ]31 gene. Blood 83:3664-3671. 35. Wlodarska I, Schoenmakers E, KAs K, Merregaert J, Lemaheiu V, Weier U, Van den Berghe H, Van den Ven WJM (1993): Molecular mapping of the chromosome 11 breakpoint of t(11;17) (q13;q21) in a t(ll;14)(q13;q32)-positive B non-Hodgkin's lymphoma. Genes Chrom Cancer 6:224-229. 36. Leroux D, Hillion J, Monteil M, Le Marc'hadour F, Jacob M-C, Sotto JJ, Larsen CJ (1991): t(18;22)(q21;q11) with rearrangement of BCL2 as a possible secondary change in a lymphocytic lymphoma. Genes Chrom Cancer 3:205-209. 37. Juliusson G, Oscier DG, Fitcbett M, Ross FM, Stockdill G, Mackie MJ, Parker AC, Castoldi GL, Cuneo A, Knuutila S, Elonen E, Gahrton G (1990): Prognostic subgroups in B-cell chronic lymphocytic leukemia defined by specific chromosomal abnormalities. N Engl J Med 323:720-724. 36. Weisenburger DD, Sanger WG, Armitage JO, Purtilo I ~ (1987): Intermediate lymphocytic lymphoma: immunophenotypic and cytogenetic findings. Blood 69:1617-1621. 39. Bain B, Matures E, Robinson D, Lampert IA, Brito-Babapulle V, Morrilla R, Catovsky D (1991): Leukaemia as a manifestation of large cell lymphoma. Br J Haematol 77:301-310.