Hematopathology / LEUKEMIC NUCLEOLATED MANTLE CELL LYMPHOMA

Nucleolated Variant of Mantle Cell Lymphoma With Leukemic Manifestations Mimicking Prolymphocytic Leukemia Kit-fai Wong, MD, Chi-chiu So, MRCPath, and John K.C. Chan, FRCPath Key Words: Mantle cell lymphoma; Nucleolated variant; Cyclin D1; t(11;14); Prolymphocytic leukemia; Blood; Lymph node

Chronic lymphoproliferative disorders sometimes can be difficult to classify. We report 4 cases characterized by large cells with distinct central nucleoli, reminiscent of prolymphocytic leukemia, but shown on further workup to represent mantle cell lymphoma. At initial examination, the patients had generalized lymphadenopathy, splenomegaly, and a leukemic blood picture. The peripheral blood showed many large cells with round to slightly irregular nuclei, single central nucleoli, and a fair amount of pale cytoplasm. The picture was not typical of prolymphocytic leukemia because of the presence of generalized lymphadenopathy and the large size of the circulating abnormal cells. Immunophenotypic study showed that the large lymphoid cells were CD5+ CD23– mature B cells with overexpression of cyclin D1, and cytogenetic study demonstrated the translocation t(11;14)(q13;q32) in 3 patients. Lymph node biopsy confirmed a diagnosis of mantle cell lymphoma, pleomorphic variant, in all 4 patients. This study documents the existence of an unusual leukemic form of mantle cell lymphoma with prominent nucleoli; the clinicopathologic features that distinguish it from other chronic lymphoproliferative disorders are discussed.

246

Am J Clin Pathol 2002;117:246-251

Mantle cell lymphoma (MCL) is a lymphoid malignant neoplasm of mature pregerminal center naive B cells that express CD5, surface IgM, and surface IgD, but not CD23. The hallmark of this lymphoma is overexpression of cyclin D1, attributable to t(11;14)(q13;q32) causing juxtaposition of the bcl-1 (cyclin D1) gene to the immunoglobulin heavy chain gene, or other mechanisms deregulating the bcl-1 gene.1 Besides the classic type characterized by small cells with hyperchromatic nuclei, the blastoid and pleomorphic variants also have been recognized.2,3 Peripheral blood and bone marrow involvement is not uncommon in MCL during the course of disease.4 In a report on the cytologic findings of MCL manifesting with a leukemic phase, Wong et al 5 observed in 1 patient the occurrence of leukemic cells that superficially resembled oversized prolymphocytes. We since have observed 3 additional cases with this unusual cytologic appearance. We therefore performed a comprehensive cytologic, histologic, and immunologic analysis on these 4 cases.

Materials and Methods Case Selection During the period July 1994 to December 2000, 20 patients were given a diagnosis of leukemic MCL at the Queen Elizabeth Hospital, Hong Kong, People’s Republic of China. The diagnosis of MCL was established based on an immunophenotype of CD5+ CD19+ CD23– and overexpression of cyclin D1. This was supplemented by lymph node histologic features and cytogenetic findings of t(11;14)(q13;q32). The 4 cases included in the study all © American Society for Clinical Pathology

Downloaded from http://ajcp.oxfordjournals.org/ by guest on January 20, 2017

Abstract

Hematopathology / ORIGINAL ARTICLE

❚Table 1❚ Clinical, Hematologic, and Cytogenetic Data of Leukemic Nucleolated Mantle Cell Lymphoma* Blood Counts Case No./ Sex/Age (y) 1/M/65

2/M/73

3/F/68

History of rheumatoid arthritis treated by methotrexate; generalized lymphadenopathy and massive splenomegaly; normal serum immunoelectrophoresis but free kappa light chain detected in urine; given CVP; DOD, 13 mo Marked weight loss, generalized lymphadenopathy, massive splenomegaly; borderline elevated IgG (16.8 g/L [reference range, 7-16 g/L]); given CVP; DOD, 6 wk Marked weight loss, generalized lymphadenopathy, massive splenomegaly; diffuse increase in immunoglobulin levels (IgG, 17.9 g/L [reference range, 7-16 g/L]; IgM, 5.1 g/L [reference range, 0.4-2.3 g/L]; IgA, 6.2 g/L [reference range, 0.7-4 g/L]) with IgM lambda and free lambda light chain detected in serum and urine, respectively; given CVP; DOD, 4 mo Marked weight loss, generalized lymphadenopathy, hepatosplenomegaly; normal immunoglobulin levels; given CVP; alive with disease, 5 mo

Hb

Plt

WBC

N

L

M

E

MC

Cytogenetic Findings

10.6

199

13.9

32

22

4

2

40

46,XY[18]

11.0

52

27.5

26

23

4

1

46

9.5

69

50.9

21

9

3

1

66

38~45,X,–Y,add(3)(q29),–9, –10,t(11;14)(q13;q32),add(13) (q34),del(17)(p13),add(21) (q22),+mar[cp7]/ 46,XY[12] 40,X,–X,–5,–8,–9,–10,dup(10) (q22q26),t(11;14)(q13;q32), –13,der(16)?t(3;16)(q11;q24), –17,add(19)(p13.3),–20,–21, der(22)?t(6;22)(q11;p11),+mar1, +mar2,+mar3[5]/ 46,XX[5]

10.7

106

48.7

29

4

3

0

64

49,X,?t(Y;1)(q12;p22),+del(3) (p11p21),add(5)(q35),+7,i(8) (q10),?inv(10)(p11q22),t(11;14) (q13;q32),+13,–15,add(15) (q26),der(17)?t(17;20) (p11;p11),+18[1]/46,XY[9]

CVP, cyclophosphamide, vincristine, prednisolone; DOD, died of disease; MC, mantle cells (given as percentage of leukocytes). * Unless stated otherwise, values are given in Système International (SI) units; conversions to conventional units are as follows: IgA, IgG, and IgM, divide by 0.01 for mg/dL; hemoglobin (Hb; g/dL SI), divide by 0.01 for mg/dL; platelets (Plt; × 109/L SI), divide by 1.0 for × 103/µL; WBC (× 109/L SI), divide by 0.001 for /µL. Values for neutrophils (N), lymphocytes (L), monocytes (M), and eosinophils (E) are percentages, which are conventional units; to convert to SI, multiply by 0.01 for the proportion of 1.00.

showed distinct central nucleoli. One case had been included in a previous report on MCL in leukemic phase.5 The clinical records were reviewed. The peripheral blood films, bone marrow aspirate smears, and trephine and lymph node biopsy specimens were retrieved for study. Cytologic and Histologic Studies The blood films and bone marrow aspirate smears were stained with May-Grünwald Giemsa. Lymph node biopsy specimens from all 4 cases and trephine biopsy specimens from cases 1 through 3 were available for study. Specimens were formalin fixed, paraffin embedded, sectioned, and stained with H&E. The trephine biopsy specimens were decalcified in EDTA. Immunohistochemical Studies Sections cut from the lymph node biopsy specimens were immunostained with the following monoclonal antibodies: NCL-CD5-4C7 to CD5 (Novocastra, Newcastleupon-Tyne, England); NCL-CD23-1B12 to CD23 (Novocastra); DCS-6 to cyclin D1 (Ventana, Tucson, AZ); 1F8 and Ber-MAC-DRC to CD21 and CD35, respectively, to highlight the follicular dendritic cell meshwork (Dakopatts, © American Society for Clinical Pathology

Glostrup, Denmark); and DO-7 to p53 protein (Dakopatts). The streptavidin-biotin-peroxidase complex detection system was used, using the Ventana ES automated immunostainer. Antigen retrieval was achieved by heating the slides in EDTA buffer at pH 8 in a pressure cooker for 2.5 minutes. An appropriate positive control was mounted on every slide to ascertain the validity of the stain.

Results Clinical Findings The patients were 3 men and 1 woman. Their mean age was 67.8 years (range, 65-73 years), and they had generalized lymphadenopathy and massive splenomegaly at the initial examination ❚Table 1❚. The peripheral blood counts showed leukocytosis (13,900-50.900/µL [13.9-50.9 × 109/L]) with a WBC count around 50,000/µL (50 × 109/L) in 2 patients. Circulating mantle cells accounted for 40% to 66% of the leucocytes (mean, 54%). Cytogenetic studies showed complex chromosomal abnormalities with t(11;14)(q13;q32) in 3 patients ❚Image 1❚. All of them were treated with combination Am J Clin Pathol 2002;117:246-251

247

Downloaded from http://ajcp.oxfordjournals.org/ by guest on January 20, 2017

4/M/65

Clinical Features

Wong et al / LEUKEMIC NUCLEOLATED MANTLE CELL LYMPHOMA

chemotherapy that included cyclophosphamide, vincristine, and prednisolone with poor response. Three patients died in 6 weeks to 13 months (mean, 6 months), while 1 patient was alive with disease after 5 months.

– q13 – q32

11

der(11)

14

der(14)

A

B

❚Image 2❚ A (Case 3), Peripheral blood sample showing a predominance of large cells that superficially resemble oversized prolymphocytes (Romanowsky, ×400). B (Case 4), The large mantle cells have round to irregular nuclei with somewhat lacy chromatin, single distinct nucleoli, and an appreciable amount of pale cytoplasm (Romanowsky, ×1,000). C (Case 3), Occasional giant cell with a hyperlobulated nucleus and a narrow rim of cytoplasm can be found (Romanowsky, ×1,000).

C

248

Am J Clin Pathol 2002;117:246-251

© American Society for Clinical Pathology

Downloaded from http://ajcp.oxfordjournals.org/ by guest on January 20, 2017

❚Image 1❚ Partial karyotype showing t(11;14)(q13;q32) in case 2 (G-banding with trypsin-Giemsa).

Cytologic Findings In all 4 cases, the abnormal circulating lymphoid cells were predominantly (>90%) large cells (3-4 times the size of an RBC) and had round, angular to irregular nuclei with slightly clumped chromatin; a prominent, often single nucleolus; and a fair amount of pale basophilic cytoplasm ❚Image 2❚. Occasional giant cells (>4 times the size of an RBC) with markedly folded nuclei, multiple nucleoli, and only a narrow rim of cytoplasm could be found in cases 2 through 4 (Image 2C). In the marrow aspirate smears, similar large cells were found and accounted for about 50% of the marrow nucleated cells (range, 20%-69%) ❚Image 3A❚.

Hematopathology / ORIGINAL ARTICLE

A

B

A

B

❚Image 4❚ A, Lymph node biopsy specimen showing an infiltrate of small to medium-sized lymphoid cells together with large cells with a single and distinct nucleolus adjacent to a residual follicle (H&E, ×400). B, Immunostaining shows that the abnormal lymphocytes express cyclin D1 (streptavidin-biotin peroxidase, ×400).

Histologic Findings The lymph node architecture was effaced by a vaguely nodular to diffuse infiltrate of small to medium-sized lymphoid cells that had irregular to folded nuclei, mixed with some larger cells with a single and distinct nucleolus ❚Image 4A❚. Prolymphocytes, paraimmunoblasts, and proliferation centers were not found. The trephine biopsy specimens showed an interstitial to nodular infiltrate of a mixed population of small, medium to large cells with prominent © American Society for Clinical Pathology

nuclear irregularities ❚Image 3B❚. No paratrabecular accentuation was demonstrated. Immunohistochemical Findings The lymphoma cells expressed CD5 but not CD23. Strong nuclear staining for cyclin D1 ❚Image 4B❚ also was demonstrated. p53 protein was positive only in case 2. In all 4 cases, irregular meshwork of follicular dendritic cells could be highlighted by simultaneous staining for CD21 and CD35. Am J Clin Pathol 2002;117:246-251

249

Downloaded from http://ajcp.oxfordjournals.org/ by guest on January 20, 2017

❚Image 3❚ A (Case 2), Marrow aspirate showing similar large mantle cells intermixed with hematopoietic cells (Romanowsky, ×1,000). B (Case 3), Trephine biopsy specimen showing an interstitial to nodular infiltrate of large mantle cells (H&E, ×400).

Wong et al / LEUKEMIC NUCLEOLATED MANTLE CELL LYMPHOMA

A

B

Discussion MCL was first characterized in the Kiel Classification in 1974 as “centrocytic lymphoma.”6 It was not until the early 1990s that the term “mantle cell lymphoma” was used to specify a mature B-cell lymphoma with a distinctive immunophenotype of CD5+ CD23–, translocation t(11;14)(q13;q32), and overexpression of the cyclin D1 gene.7 Cyclin D1 overexpression has become a defining feature and also has helped in recognizing the broader morphologic spectrum of MCL. Cytologically, the mantle cells often are described as being small to medium-sized with clefted nuclei and scanty cytoplasm. The leukemic form of mantle cell lymphoma has also been described.5,8,9 In the present report, we describe the unusual cytologic findings in 4 cases of pleomorphic variant of MCL in leukemic phase characterized by prominent single nucleoli. Unlike the variant form of hairy cell leukemia ❚Image 5A❚, the leukemic mantle cells have less condensed chromatin and do not show cytoplasmic projections.10 The nucleolated leukemic mantle cells resemble oversized prolymphocytes because of the presence of a single central nucleolus and an appreciable amount of pale cytoplasm, but the nuclear/cytoplasmic ratio is higher ❚Image 5B❚. Cytologically, this type of leukemic MCL can be distinguished from prolymphocytic leukemia by the large size of the circulating tumor cells. The presence of giant hyperlobulated cells with a high nuclear/cytoplasmic ratio on careful scrutiny of the blood films also may help in the differentiation. Furthermore, the clinical manifestations are unusual for prolymphocytic 250

Am J Clin Pathol 2002;117:246-251

leukemia, which usually is associated with splenomegaly but no peripheral lymphadenopathy.1,11 The tumor cells showed an immunophenotypic profile of CD5+ CD23–, and all of them exhibited overexpression of cyclin D1, with t(11;14)(q13;q32) demonstrated in 3 cases. Although cyclin D1 overexpression with or without the translocation t(11;14) has been described in occasional cases of chronic lymphocytic leukemia (CLL) or prolymphocytic leukemia,12-14 lymph node histologic features, which are of great help for the differentiation between MCL and CLL, are lacking in most of the reported cases. In fact, it has been shown that a substantial proportion of cases previously classified as CLL with t(11;14)(q13;q32) should be reclassified as MCL or other entities on histologic examination of the lymph node or spleen.15 Levy et al16 described a subset of probable MCL-related tumors with tumor cells showing prominent nucleoli. Schlette et al17 also suggested that some cases of cyclin D1–positive, t(11;14)-positive prolymphocytic leukemia should best be classified as “prolymphocytoid variant” MCL. It is unfortunate that a lymph node biopsy specimen was available in only 1 of the 4 cases reported by them. On the other hand, the availability of lymph node biopsy specimens in all 4 of our cases confirmed the diagnosis of MCL. The lymph nodes in both CLL and prolymphocytic leukemia usually contain paraimmunoblasts and pseudofollicular proliferation centers,18,19 features that were absent in our cases. Furthermore, irregular follicular dendritic cell meshwork, a characteristic histologic feature of MCL but not CLL or prolymphocytic leukemia,20 can be found in our cases. © American Society for Clinical Pathology

Downloaded from http://ajcp.oxfordjournals.org/ by guest on January 20, 2017

❚Image 5❚ A, A case of hairy cell leukemia variant for comparison. Note the condensed chromatin and the fluffy cytoplasmic border (Romanowsky, ×1,000). B, A case of prolymphocytic leukemia for comparison. Note the smaller cells and more condensed chromatin (Romanowsky, ×1,000).

Hematopathology / ORIGINAL ARTICLE

From the Department of Pathology, Queen Elizabeth Hospital, Hong Kong, People’s Republic of China. Address reprint requests to Dr Wong: Dept of Pathology, Queen Elizabeth Hospital, 30 Gascoigne Rd, Kowloon, Hong Kong SAR, China.

References 1. Harris NL, Jaffe ES, Diebold J, et al. World Health Organization classification of neoplastic diseases of the hematopoietic and lymphoid tissues: report of the Clinical Advisory Committee meeting—Airlie House, Virginia, November 1997. J Clin Oncol. 1999;17:3835-3849. 2. Campo E, Raffeld M, Jaffe ES. Mantle-cell lymphoma. Semin Hematol. 1999;36:115-127. 3. Ott G, Kalla J, Hanke A, et al. The cytomorphological spectrum of mantle cell lymphoma is reflected by distinct biological features. Leuk Lymphoma. 1998;32:55-63. 4. Cohen PL, Kurtin PJ, Donovan KA, et al. Bone marrow and peripheral blood involvement in mantle cell lymphoma. Br J Haematol. 1998;101:302-310. 5. Wong KF, Chan JK, So JC, et al. Mantle cell lymphoma in leukemic phase: characterization of its broad cytologic spectrum with emphasis on the importance of distinction from other chronic lymphoproliferative disorders. Cancer. 1999;86:850-857. 6. Gerard-Marchant R, Hamlin I, Lennert K, et al. Classification of non-Hodgkin’s lymphomas. Lancet. 1974;ii:406-408. 7. Banks PM, Chan J, Cleary ML, et al. Mantle cell lymphoma: a proposal for unification of morphologic, immunologic, and molecular data. Am J Surg Pathol. 1992;16:637-640. 8. Neilson JR, Fegan CD, Milligan DW. Mantle cell leukaemia [letter]? Br J Haematol. 1996;93:494-495. 9. Singleton TP, Anderson MM, Ross CW, et al. Leukemic phase of mantle cell lymphoma, blastoid variant. Am J Clin Pathol. 1999;111:495-500. 10. Matutes E, Wotherspoon A, Brito-Babapulle V, et al. The natural history and clinico-pathological features of the variant form of hairy cell leukemia [letter]. Leukemia. 2001;15:184-193.

© American Society for Clinical Pathology

11. Bennett JM, Catovsky D, Daniel MT, et al, for the FrenchAmerican-British (FAB) Cooperative Group. Proposals for the classification of chronic (mature) B and T lymphoid leukaemias. J Clin Pathol. 1989;42:567-584. 12. Brito-Babapulle V, Ellis J, Matutes E, et al. Translocation t(11;14)(q13;q32) in chronic lymphoid disorders. Genes Chromosomes Cancer. 1992;5:158-165. 13. Cuneo A, Balboni M, Piva N, et al. Atypical chronic lymphocytic leukaemia with t(11;14)(q13;q32): karyotype evolution and prolymphocytic transformation. Br J Haematol. 1995;90:409-416. 14. De Angeli C, Gandini D, Cuneo A, et al. bcl-1 rearrangements and p53 mutations in atypical chronic lymphocytic leukemia with t(11;14)(q13;q32). Haematologica. 2000;85:913-921. 15. Dascalescu C, Gressin R, Callanan M, et al. t(11;14)(q13;q32): chronic lymphocytic leukaemia or mantle cell leukaemia [letter]? Br J Haematol. 1996;95:572-573. 16. Levy V, Ugo V, Delmer A, et al. Cyclin D1 overexpression allows identification of an aggressive subset of leukemic lymphoproliferative disorder. Leukemia. 1999;13:13431351. 17. Schlette E, Bueso-Ramos C, Giles F, et al. Mature B-cell leukemias with more than 55% prolymphocytes: a heterogeneous group that includes an unusual variant of mantle cell lymphoma. Am J Clin Pathol. 2001;115:571-581. 18. Bonato M, Pittaluga S, Tierens A, et al. Lymph node histology in typical and atypical chronic lymphocytic leukemia. Am J Surg Pathol. 1998;22:49-56. 19. Bearman RM, Pangalis GA, Rappaport H. Prolymphocytic leukemia: clinical, histopathological, and cytochemical observations. Cancer. 1978;42:2360-2372. 20. Kumar S, Green GA, Teruya-Feldstein J, et al. Use of CD23 (BU38) on paraffin sections in the diagnosis of small lymphocytic lymphoma and mantle cell lymphoma. Mod Pathol. 1996;9:925-929. 21. Zoldan MC, Inghirami G, Masuda Y, et al. Large-cell variants of mantle cell lymphoma: cytologic characteristics and p53 anomalies may predict poor outcome. Br J Haematol. 1996;93:475-486. 22. Viswanatha DS, Foucar K, Berry BR, et al. Blastic mantle cell leukemia: an unusual presentation of blastic mantle cell lymphoma. Mod Pathol. 2000;13:825-833. 23. O’Brien SM, Kantarjian HM, Cortes J, et al. Results of the fludarabine and cyclophosphamide combination regimen in chronic lymphocytic leukemia. J Clin Oncol. 2001;19:14141420. 24. Kantarjian HM, Childs C, O’Brien S, et al. Efficacy of fludarabine, a new adenine nucleoside analogue, in patients with prolymphocytic leukemia and the prolymphocytoid variant of chronic lymphocytic leukemia. Am J Med. 1991;90:223-228. 25. Winkler U, Jensen M, Manzke O, et al. Cytokine-release syndrome in patients with B-cell chronic lymphocytic leukemia and high lymphocyte counts after treatment with an anti-CD20 monoclonal antibody (rituximab, IDEC-C2B8). Blood. 1999;94:2217-2224. 26. Foran JM, Rohatiner AZ, Cunningham D, et al. European phase II study of rituximab (chimeric anti-CD20 monoclonal antibody) for patients with newly diagnosed mantlecell lymphoma and previously treated mantle-cell lymphoma, immunocytoma, and small B-cell lymphocytic lymphoma. J Clin Oncol. 2000;18:317-324.

Am J Clin Pathol 2002;117:246-251

251

Downloaded from http://ajcp.oxfordjournals.org/ by guest on January 20, 2017

Our cases probably correspond to the leukemic phase of the large cell variant of pleomorphic MCL described by Zoldan et al,21 although the lymph node biopsy specimens in our cases did not show a pure large cell component. They are distinguishable from the blastoid variant of MCL, which is composed of small to medium-sized lymphoblast-like cells with fine chromatin and inconspicuous nucleoli.9,22 It is important to distinguish MCL in leukemic phase from CLL and prolymphocytic leukemia because the prognosis and treatment are different. It has been shown that the efficacy of purine analogue for the treatment of these mature B-cell lymphoproliferative disorders probably is different. Fludarabine is less effective in MCL than in CLL and prolymphocytic leukemia. 23,24 It also has been suggested that the chimeric anti-CD20 monoclonal antibody, rituximab, has moderate activity in MCL but not in CLL and small lymphocytic lymphoma.25,26