Monoclonal immunoglobulins and autoantibodies in lymphoid malignancies

The presence of serum monoclonal or oligoclonal immunoglobulins (paraproteins) was investigated in 38 non-Hodgkin's lymphoma and chronic lymphocytic leukemia patients, 33 patients with solid tumors and 33 healthy individuals. Seventy two percent of non-Hodgkin's lymphoma and 31% of chronic lymphocytic leukemia patients had serum paraproteins, in contrast to 21% and 15% of solid tumor patients and normal controls respectively. There was no significant prevalence of a certain isotype or light chain in the non-Hodgkin's lymphoma, chronic lymphocytic leukemia and solid tumor groups. In the healthy individuals all bands were monoclonal of the IgG isotype. No correlation was found between histologic grading of lymphoid malignancy or disease stage and serum monoclonality. No serologic or histologic autoimmune features were demonstrated in non-Hodgkin's lymphoma and chronic lymphocytic leukemia patients. In addition, no correlation was found between serum autoantibody activity and mono- or oligoclonal immunoglobulins.     

Non-Hodgkin's lymphoma primarily involving the bronchial tree

Among extranodal localizations, the bronchial one is very unusual, especially as primary involvement. The authors present 2 cases of non-Hodgkin's lymphoma (NHL) admitted to the hospital because of thoracic abnormalities. Chest x-ray revealed lobar atelectasis. Fiberoptic bronchoscopic findings agreed with the diagnosis of unresectable bronchogenic tumor in both cases. Histologic examination of biopsy specimens was nonrevealing in the first patient, and suggested small cell lung cancer in the second one. Further histologic and immunohistochemical examinations excluded bronchial tumors (particularly small cell bronchogenic carcinoma) and led to the diagnosis of lymphocytic lymphoma in one case and centroblastic lymphoma in the other. In the differential diagnosis of bronchogenic tumors, it is necessary to keep in mind the hypothesis of lymphomatous involvement of the bronchial wall, although it rarely occurs.     

Monocytoid B-cell lymphoma arising in extranodal organs

Six cases of monocytoid B-cell lymphoma (MBCL) developing in extranodal sites (thyroid, three; stomach, two; rectum, one) are described. Patients were all women aged 46 to 65 years (median, 53 years). Three patients with thyroid lymphoma presented with an increasing goiter, two with positive serum antithyroid antibodies, and one patient had chronic lymphocytic thyroiditis (CLTH). The histologic type of surgically resected specimens was a diffuse proliferation of atypical lymphoid cells with monocytoid appearance, i.e., abundant pale cytoplasm with distinct cell border and small reniform nucleus. These cells were CD20+, 22+, 24-, 9- showing their B-cell origin. The monoclonal nature of the proliferating cells was confirmed by restricted expression of immunoglobulin (Ig) light chain and/or gene rearrangement study in three cases. Two cases of thyroid lymphoma in which the monoclonality could not be confirmed had histologic appearances characteristic of malignant lymphoma. All three patients with gastric or rectal lymphoma had reactive lymphoid hyperplasia (RLH) near the tumors. These findings showed presence of MBCL in the extranodal sites with invariable coexistence with lymphoid follicles formed by CLTH in thyroid or RLH in stomach and rectum.     

Pulmonary lymphomas and other pulmonary lymphoid lesions. A clinicopathologic and immunologic study of 64 patients

Sixty-four patients with lymphoid lesions involving the lung were separated into three groups. In 32 patients, the predominant lymphoid cell population consisted of small, mature-appearing round lymphocytes with or without plasmacytoid features. This group, designated small lymphocytic proliferation (SLP), represents a heterogeneous group of pulmonary lymphocytic lesions including small lymphocytic lymphoma, lymphocytic interstitial pneumonia, and lymphoid hyperplasia (pseudolymphoma). Thirteen SLP patients were identified as having small lymphocytic lymphoma on the basis of monoclonality, progressive disease in other sites, or both. This group was morphologically identical to the remainder of the SLP patients, except for a higher incidence of plasmacytoid features (P = 0.003) and a greater degree of mast cell infiltration (P less than 0.05). Four of these 13 patients subsequently developed an aggressive large cell lymphoma resulting in death in three patients. The median survival for all of the SLP patients has not yet been reached. Patients in whom a monoclonal cell population could be established showed a slightly worse prognosis of borderline statistical significance (P = 0.09); however, the presence of a serum monoclonal gammopathy conveyed a significantly worse prognosis (P = 0.003). The remaining two groups of patients had various forms of malignant lymphoma other than the small lymphocytic type. One group of 12 patients, designated as having presumed primary lymphoma limited to one or both lungs (PL), had a prolonged course with a median survival of 117 months. The remaining 20 patients had disseminated lymphoma also involving lung (DL); DL patients had a shorter median survival of 33 months.     

Prognostic factors for pleural lymphoma patients.

Prognostic factors in 47 patients with pleural lymphocytic lymphoma developing in chronic tuberculous pyothorax were evaluated using Cox's proportional hazards model. There were 41 men and six women, aged 44-80 (median 61) years. Approximately 70% of the patients had localized disease in Stages I and II, and 30% advanced disease in Stages III and IV. Histologically, 27 patients had the diffuse large, immunoblastic type and 12 had others. In the other seven patients, histological subtyping of the lymphocytic lymphoma was impossible because of degenerative or necrotic changes in the histologic specimens. A diagnosis of lymphocytic lymphoma of B-cell type was made in one case using combined cytologic and surface maker findings on a cell suspension. In addition, immunologic and immunohistochemical studies revealed another 40 cases to be proven B-cell lymphomas. Poor performance status and elevated levels of BUN and GPT were significantly associated with shortened survival in a Cox's proportional hazards model. A poor performance status and high levels of serum BUN and GPT suggested a marked deterioration in a patient's condition. When compared with previous literature describing prognostic factors in patients with B-cell lymphomas and with lymphocytic lymphomas with unfavorable histologies or associated with long-standing inflammations, the only common prognostic factors was performance status. The significance of primary site in predicting survival from lymphocytic lymphoma is discussed.     

结内边缘带B细胞淋巴瘤伴有单克隆IgM增高两例并文献复习

 目的　分析结内边缘带B细胞淋巴瘤（NMZL）伴有单克隆IgM增高病例的临床及病理特点、诊断、治疗及预后。方法　对2例NMZL病例进行分析并进行文献综述。结果　惰性B细胞淋巴瘤伴有单克隆免疫球蛋白升高,最常见的两种病理类型为NMZL和B-SLL／CLL。NMZL主要累及淋巴结、脾脏、骨髓,60 %发病时为进展期,国际预后指数（IPI）评分为高危,诊断主要依据淋巴结病理,单核样B细胞增生及分布有重要的参考价值。Ⅰ和（或）Ⅱ期化疗疗效好,进展期疗效差。结论　NMZL主要累积淋巴结、脾脏、骨髓,可伴有单克隆IgM增多,发病时多处于疾病进展期,预后不佳。     

The clinical spectrum of pure Bence Jones proteinuria. A study of 66 patients

Sixty-six consecutive patients exhibiting isolated urinary excretion of monoclonal free light chains, i.e. Bence Jones protein (BJP), on screening investigation for serum and urine monoclonal immunoglobulins were studied in order to better define the spectrum of immunoproliferative disorders associated with such a protein abnormality. The typical plasma cell neoplasms accounted for only one third of the cases, multiple myeloma (MM) and systemic amyloidosis (AL) being diagnosed in 18% and 15% of the patients, respectively. Eighteen (27%) of the patients were recognized as having malignant nonHodgkin's lymphomas (NHL), 21 (32%) had chronic lymphocytic leukemia (CLL), and 2 (3%) had hairy cell leukemia (HCL). Three patients (5%) without apparent evidence of any malignant immunoproliferative disease were classified as having a monoclonal gammopathy of undetermined significance (MGUS). The greatest urinary concentrations of BJP were found in plasmacytic neoplasms, the daily excretion of MM patients being significantly higher than that of AL patients. Considerably lower BJP outputs were recorded in the other diseases, the lowest ones being associated with MGUS. NHL patients had a daily excretion four times higher as compared with that of CLL patients. The distribution of NHL by histologic type was: follicular center cell lymphomas (FCCL) 39%, small lymphocytic lymphoma (SLL) 33%, immunoblastic lymphoma (IBL) 17%, and plasmacytoid lymphocytic lymphoma (PLL) 11%. The highest BJP levels were found in PLL, and the lowest ones in FCCL. In CLL patients the amount of urinary BJP correlated significantly with the tumor load, as estimated by the number of enlarged lymphoid areas. The study suggests that detection and measurement of isolated urinary BJP may provide useful data for the clinical evaluation of a wide spectrum of immunoproliferative disorders.     

Differential diagnosis of Waldenstrom's macroglobulinemia and other B-cell disorders

Waldenstrom's macroglobulinemia (WM) is characterized by lymphoplasmacytic infiltration of bone marrow and/or other tissues and by the presence of serum monoclonal immunoglobulin M ([IgM], without cutoff limit). Differential diagnosis from other B-cell disorders (BCDs) is usually easy based on clinical, morphologic, histopathologic, immunophenotypic, and genetic features. However, all BCDs potentially produce monoclonal IgM. In this study we reviewed the medical files of 130 patients with IgM-secreting BCDs. Eighty-four patients were diagnosed with WM, 5 with IgM-monoclonal gammopathy of undetermined significance (MGUS), and 41 with other BCDs (9 with B-cell chronic lymphocytic leukemia, 5 with small lymphocytic lymphoma, 14 with marginal zone lymphoma, 5 with mantle-cell lymphoma, 2 with follicular lymphoma, 2 with diffuse large B-cell lymphoma, 2 with cryoglobulinemia, and 2 with low-grade lymphoma not otherwise specified). Median IgM levels were 3215 mg/dL in WM, 840 mg/dL in IgM-MGUS, and 285 mg/dL in other BCDs (5 had IgM levels > 1500 mg/dL). In 10% of non-WM BCDs, monoclonal IgM was found only when more sensitive immunofixation methods were used. Forty-four percent of patients with BCDs (splenic marginal zone lymphoma or small lymphocytic lymphoma) had diagnoses that corresponded to that of WM. Careful diagnosis requires the concomitant evaluation of all parameters of BCDs together. Marginal zone lymphoma is the most frequently overlapping entity. Special attention should be given to mantle cell lymphoma in its atypical forms. Research in this field should continue to further clarify the disease entities that overlap with WM. New technology such as gene-expression profile techniques may contribute to this purpose.     

CD5+ true SLL/CLL with plasmacytic differentiation and an unusual 1p36 translocation: case report and review of the literature

Lymphoplasmacytic lymphoma (LPL) and small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL)are distinct clinicopathologic entities. Although some cases of SLL/CLL may show plasmacytic differentiation and be associated with monoclonal immunoglobulin in serum, such cases appear to be very rare, and if plasma cell differentiation were marked, differentiation of SLL/CLL from LPL could be difficult. We report a rare case of true CD5-positive small lymphocytic lymphoma/chronic lymphocytic leukemia with unequivocal plasmacytic differentiation. This case also showed an abnormality of chromosome 1p36 not previously described in small lymphocytic lymphoma/chronic lymphocytic leukemia.     

Primary pulmonary lymphoma. A clinical and immunohistochemical study of six cases

Six patients with lymphomatous lesions primarily involving the pulmonary parenchyma were studied. In these patients, both the history and physical findings were vague and minimal. The laboratory findings also were nonspecific, although the findings of large multiple lesions in the lungs and pleural adhesion or effusion were more consistent with lymphoma. Histologic examination revealed lymphocytic infiltration of the pulmonary parenchyma in all six patients and presence of germinal or growth centers in some areas of the lesions in four. The hilar or mediastinal lymph nodes were not involved in five patients so examined. Immunocytochemical study of cytoplasmic immunoglobulin revealed monoclonal lymphocytic proliferation in five patients and negative staining in one patient. Clinical, histologic, or immunohistochemical studies alone may not be sufficient to detect all of the lymphomatous lesions. The combined use of all of these parameters is more advantageous for accurate diagnosis of these lesions. Treatment is surgical resection. Radiotherapy or chemotherapy are used when residual disease is present after surgery. Three patients died of disseminated lymphoma 96, 42, and 8 months after diagnosis, respectively, and three patients are still alive at 18, 24, and 4 months, respectively.     

Clinicopathologic spectrum of cutaneous manifestations in systemic follicular lymphoma. A study of 11 patients

Follicular lymphoma is rarely diagnosed on the basis of only a cutaneous biopsy. Eleven patients with primary follicular lymphoma of lymph nodes who developed skin lesions were studied. Skin lesions involved the scalp, head and neck, trunk, and buttocks and were small cleaved cell type in four cases, large cell type in three cases, and mixed type in four cases. The follicular pattern with a bottom-heavy distribution was identified in only six of the 11 cases. One case showed a nodular, perivascular pattern in the deep dermis and subcutaneous tissue. Four cases were characterized by a diffuse pattern of lymphocytic infiltrate. One patient with a diffuse pattern had an isolated subepidermal band of lymphoma cells representing primary cutaneous T-cell lymphoma. Cutaneous involvement by lymphoma previously diagnosed as low-grade (follicular growth pattern) transformed to higher grade disease in five of ten asynchronous cases. The 5-year survival rate was 60% among the transformed cases and 100% among the nontransformed cases. Extranodal cutaneous involvement in follicular lymphoma occurred in 3.8% of cases. The correct histologic diagnosis in a skin biopsy specimen can be established in cases with a follicular pattern (60%) with conventional histologic criteria such as redundancy of follicles, uniformity of follicular center cell composition, lack of interspersed phagocytic histiocytes, and absence of immunosecretory cellular elements such as plasma cells and immunoblasts.     

Lymphocyte markers and clinical expression of lymphoproliferative disorders with moderate lymphocytosis

Lymphoproliferative syndrome with well differentiated lymphocytes and moderate lymphocytosis in the peripheral blood includes a heterogeneous group of disorders, that present often difficulties in classification. We have studied the lymphocyte markers (ER, EMR, sIg and T3, T4, T8 antigens) in 36 cases who had lymphocytic infiltration in the bone marrow and peripheral lymphocyte counts less than 15 X 10(9) l-1. Four cases (11.1%) had the characteristics of T8 lymphocytosis and 31 had a B cell monoclonal proliferation in the peripheral blood. Of these, four were sIg-, EMR+, 19 were sIg+, EMR+ and 8 were sIg+, EMR-. Most patients (17/32) had the clinical picture of stage 0 and I B-CLL. Six cases presented as pure splenomegalic form of CLL, three had the features of immunocytic lymphoma and five had the features of lymphocytic lymphoma. It is concluded that the majority of lymphoproliferative disorders presenting with moderate lymphocytosis represent early forms of B-CLL. Occasionally cases of lymphocytic or immunocytic lymphoma may present problems of differential diagnosis since there may be a dissociation of phenotypic characteristics of lymphocytes between tissues and peripheral blood.     

Malignant lymphomas of the thyroid: a clinical pathologic study of 35 patients including ultrastructural observations.

The clinical and pathologic findings for 35 patients with malignant lymphoma presenting in the thyroid are reviewed. The lymphomas tended to occur in females with a median age of 65 years and clinically were manifested by a mass in the neck. The majority of patients were euthyroid and thyroid scans demonstrated cold nodules. In none of the patients was there clinical suspicion of lymphoma prior to surgery. Thirty-four of the cases were histiocytic lymphomas; the one exception; a patient with nodular poorly differentiated lymphocytic lymphoma, had histiocytic lymphoma in a subsequent biopsy of the soft tissues of the neck. Although classified as histiocytic, the lymphomas had the histologic and ultrastructural features of transformed lymphocytes or immunoblasts. Lending possible additional credence to the immunoblastic nature of these lymphomas was the histologic documentation of chronic lymphocytic thyroiditis in all 27 cases where residual thyroid parenchyma remained. This relationship suggests possible evolution of thyroid lymphomas from chronic lymphocytic thyroiditis and probably is analogous to the malignant lymphomas developing in other altered immune states, including Sjogren's syndrome. In the current study the overall 5-year survival was 54%. Patients under age 65, without local soft tissue extension or regional lymph node involvement, and with stage I disease survived the longest; a nodular histologic pattern also appeared to favorably influence the prognosis. Improved staging procedures and newer modes of therapy appear essential, particularly for those patients with clinical stage II disease and with local extension to soft tissues.     

Expression of the activation antigen, 4F2, by non-Hodgkin's lymphomas of B-cell phenotype.

The monoclonal antibody, 4F2, which reacts with an antigen expressed by activated and proliferating cells, was applied to frozen sections of nine reactive lymphoid lesions, 146 B-cell non-Hodgkin's lymphomas (NHL), and six plasmacytic neoplasms. In reactive cases, the 4F2 antigen was expressed by germinal center cells and interfollicular immunoblasts, the activated or proliferating lymphoid cells, and histiocytes. In the malignant cases, the 4F2 antigen was expressed by 94 (64%) B-cell NHL and all six plasma cell tumors. The incidence of positivity and intensity of expression loosely correlated with the three morphologic grades of NHL identified in the Working Formulation. Approximately one half of all low-grade lymphomas, two thirds of intermediate-grade lymphomas, and all high-grade lymphomas were 4F2 positive. Similarly, the mean intensity of 4F2 antigen expression increased with higher grade. However, for certain histologic subtypes, 4F2 antigen expression did not correlate with morphologic grade. For example, in the intermediate-grade category less than one half of diffuse small cleaved cell lymphomas were 4F2 positive, and expression was weak, similar to that of low-grade lymphomas. In contrast, all other histologic subtypes of lymphoma in the intermediate-grade category were strongly 4F2 positive. Expression of 4F2 antigen also correlated with plasmacytoid differentiation. Seventy-three percent of plasmacytoid small lymphocytic lymphomas (compared with 31% of cases of non-plasmacytoid small lymphocytic lymphoma/chronic lymphocytic leukemia) and all plasma cell neoplasms expressed the 4F2 antigen, the latter cases strongly.     

Transferrin receptor expression by non-Hodgkin's lymphomas. Correlation with morphologic grade and survival

The monoclonal antibody OKT9 was applied to cryostat sections of 267 non-Hodgkin's lymphomas and related neoplasms. It was found that the transferrin receptor is expressed by a wide variety of B- and T-lineage non-Hodgkin's lymphomas. The OKT9 staining also was loosely correlated with the three morphologic grades of non-Hodgkin's lymphomas identified by the International Working Formulation. In general, higher grade lymphomas more often and more intensely expressed the T9 antigen. However, transferrin receptor expression by certain histologic subtypes of lymphoma did not correlate with their morphologic grade: low-grade follicular lymphomas expressed the T9 antigen more frequently than diffuse low-grade lymphomas; diffuse small cleaved cell lymphomas were stained by OKT9 less often than other histologic subtypes of intermediate-grade lymphomas; and diffuse immunoblastic lymphomas expressed transferrin receptors less often than the other high-grade histologic subtypes of non-Hodgkin's lymphoma. Intermediate lymphocytic lymphomas, not recognized in the International Working Formulation, were infrequently and weakly stained by OKT9 in a manner similar to diffuse low-grade lymphomas. We obtained clinical follow-up data on 43 individuals with chronic lymphocytic leukemia/small lymphocytic lymphoma and 64 individuals with diffuse large cell and immunoblastic lymphoma. Transferrin receptor expression in these two groups did not correlate significantly with survival.     

Peripheral/post-thymic T-cell lymphomas: a spectrum of disease. Clinical, pathologic, and immunologic features of 78 cases

The clinical, pathologic, and immunologic features of 78 cases of peripheral/post-thymic T-cell lymphomas are described. These neoplasms were extremely heterogeneous and were classified as small lymphocytic, mixed small and large cell, large cell, lymphoepithelioid cell, angiocentric, and adult T-cell leukemia/lymphoma type. Some cases revealed angioimmunoblastic or Hodgkin's-like features. These neoplasms mainly affected older adults (mean age, 57 years; median age, 60 years). Lymphadenopathy represented the most frequent clinical presentation, although most patients demonstrated both nodal (87%) and extranodal involvement (77%) during the course of disease. Sites of extranodal disease included skin/soft tissue, spleen, lung, liver, bone, gastrointestinal tract, central nervous system, peripheral blood, nasopharynx, and retrovaginal tissue. Splenomegaly at presentation was most frequently observed in lymphoepithelioid cell lymphomas. Angiocentric lymphomas involved lung. A mediastinal presentation was typically observed in young adults and associated with a poor prognosis. Patients with gastrointestinal lymphomas presented with bleeding and/or malabsorption. B symptoms were present in most cases (65%). Hypercalcemia occurred in four patients. Phenotypic studies of T-cell antigens demonstrated the loss of one or more pan-T-cell markers in eight of 47 cases evaluated. Assessment of T-cell subsets revealed a helper/inducer phenotype for nearly all immunoreactive cases. For the overall series, 32 patients died of disease (median survival time, 11.5 mo). There was a statistical difference between the combined groups of small lymphocytic and lymphoepithelioid cell types as compared with mixed and large cell types, with a poorer survival for the latter group. Angiocentric and adult T-cell leukemia/lymphoma were associated with poor survival. This series of T-cell lymphomas further documents the marked heterogeneity of this group of neoplasms as well as the poor prognosis observed for certain histologic types.     

Monoclonal immunoglobulin light chain in urine of patients with B lymphocytic disease: its source and use as a diagnostic aid

The presence of tumour-related monoclonal light chain has been sought in urine as an immunochemical aid in the diagnosis of B lymphocytic neoplasms. The technique of isoelectric focusing in agarose followed by immunofixation has been applied to concentrated urines from 41 patients. In chronic lymphocytic leukaemia involving neoplastic B lymphocytes, monoclonal light chain was detected in 14 out of 19 patients investigated. For 2 of the positive cases (one kappa light chain type and one lambda light chain type) the urinary light chains were compared directly with culture fluids obtained after incubation of the corresponding neoplastic cells obtained from the patient's peripheral blood: identity of the light chains from urine and cells was established by isoelectric focusing demonstrating for both patients that the tumour cells were the source of the urinary light chain. In patients with non-Hodgkin's lymphoma involving neoplastic B lymphocytes, urinary monoclonal light chains were found in 7/16 of those studied. Such light chains were not detected in 11 control subjects, in 3 patients with true histiocytic tumours or in 2 patients with enlarged reactive lymph nodes. The technique is simple to perform and provides information for diagnosis and possibly monitoring of B cell neoplasms.     

Non-Hodgkin's lymphoma in northern India. A retrospective analysis of 238 cases

A retrospective analysis was performed of 238 patients, aged 12 years and older, with non-Hodgkin's lymphoma presenting to the All India Institute of Medical Sciences, New Delhi, India, between September 1975 and December 1982. Pathologic material was reviewed and classified according to the modified Rappaport classification. The most common histologic type encountered was diffuse histiocytic lymphoma (39%), followed by diffuse poorly differentiated lymphocytic lymphoma (29%), and diffuse mixed histiocytic and lymphocytic lymphoma (9%). Nodular lymphomas constituted 9% of all non-Hodgkin's lymphomas. A lower frequency of nodular lymphomas, a lower median age of onset (45 years), and a higher male to female ratio (4.5:1) as compared with Western countries was observed. Survival information on 90 patients revealed no effect of age, sex, stage of disease, and "B" symptoms on survival, whereas histologic diagnosis had a significant influence on survival (P less than 0.05). A median survival of 24 months in 58 patients receiving chemotherapy is comparable to that reported by other investigators.     

Lymphocyte surface markers in orbital lymphoid neoplasms

Since the malignant nature of many orbital lymphoid infiltrates is difficult to assess from pathologic examination alone, over the past four years lymphocyte surface marker studies have been added to the evaluation of 23 such cases. Only 10 of the 23 could be confidently classified as malignant lymphoma by histology alone. However, monoclonal surface immunoglobulin was found in 15, supporting the pathologic diagnosis of malignancy in eight and adding seven that could not have been diagnosed otherwise. Clinical evaluation, including a median follow-up of 18 months, revealed manifestations of systemic lymphoma in six of those 15; two had been diagnosed only by surface markers. In contrast, only one of eight cases lacking monoclonal surface immunoglobulin exhibited clinical evidence of malignancy (that case was also indeterminate by histologic criteria). The addition of surface marker analysis permits more accurate diagnosis of orbital lymphoma than is possible from pathologic study alone. This technique can suggest the subtype of lymphoma.     

Immunologic cell markers of peripheral blood and lymph node lymphocytes in chronic lymphocytic leukemia

The immunologic phenotype of the lymphocytes of 100 patients with chronic lymphocytic leukaemia (CLL) was investigated. Peripheral blood lymphocytes (PBL) were examined in all cases; in 46 patients with lymphadenopathy, a lymph node was biopsied and the histologic and immunologic patterns were assessed: 24 had a lymphocytic-lymphoplasmocytoid histology and 22 the follicular variant of lymphocytic lymphoma (mantle zone lymphoma, MZL). For comparison, lymph node suspensions from 19 patients with non-leukemic centrocytic lymphoma (CCL) were also studied. Significant differences in the PBL immunologic features were found between stage O and stage I patients. The phenotype of the lymphocytes of patients with lymphocytic histology was similar to that of stage 0 CLL patients, whereas major differences were found between these patients and those with mantle zone histology. This enables these patients to be recognized easily on immunologic grounds.