T-cell-rich B-cell lymphoma

Five cases of B-cell lymphoma are described in which the morphology and initial immunohistochemistry suggested a diagnosis of T-cell neoplasia. In four cases, the histological picture was that of an adult pleomorphic T-cell lymphoma; the fifth case was a lymphocytic lymphoma (CLL) with an accompanying T-cell lymphocytosis in the peripheral blood. Immunohistochemistry on both frozen and paraffin-embedded material showed that the cellular population in all five cases consisted mainly of T-cells; less than 10% of the cells stained as B-cells. However, immunoglobulin immunostaining combined with use of the new lineage-related monoclonal antibodies reactive in paraffin section revealed that the B-cells constituted the neoplastic population. Genetic analysis showed no evidence of clonality in the T-cells, nor was it able to detect rearrangement in the small number of clonal B-cells present. These cases represent a variety of B-cell neoplasia that mimicks T-cell lymphoma morphologically and immunologically. The vigorous T-cell reaction seen in such lymphomas means that the malignant population can be correctly identified only by careful examination of the immunohistochemical findings.     

Hepatosplenic alphabeta T-cell lymphomas: a report of 14 cases and comparison with hepatosplenic gammadelta T-cell lymphomas

Hepatosplenic gammadelta T-cell lymphoma is a distinct entity, characterized by occurrence in young adult males with hepatosplenomegaly, B-symptoms, peripheral blood cytopenias, and no lymphadenopathy; lymphomatous infiltrates in the splenic red pulp, hepatic sinusoids, and bone marrow sinuses; T-cell receptor (TCR) gammadelta chains and a cytotoxic T-cell phenotype; isochromosome 7q; and an aggressive clinical course. In comparison, this study describes the clinicopathologic features of 14 hepatosplenic T-cell lymphomas expressing TCR alphabeta chains. They occurred in 11 women and 3 men with a median age of 36 years. Clinical presentation was similar to that described previously for hepatosplenic gammadelta T-cell lymphomas, except for the female preponderance and age distribution (5 patients younger than 13 years of age and 5 patients older than 50 years of age). Disease distribution was primarily in the splenic red pulp and hepatic sinusoids, although liver infiltrates were largely periportal in four cases. Bone marrow involvement, observed in eight patients, was usually interstitial and/or within the sinuses. Lymph nodes were involved in five patients, although lymphadenopathy was demonstrable in only two. Ten cases were composed of intermediate-size tumor cells with round/oval nuclei, slightly dispersed chromatin, inconspicuous nucleoli, and scant to moderate amounts of cytoplasm. Four lymphomas contained primarily large cells with irregular nuclei, dispersed chromatin, discernible nucleoli, and moderate to abundant cytoplasm. Tumor cells in all 14 lymphomas were cytotoxic alphabeta T-cells; 13 co-expressed natural killer cell-associated antigens and showed T-cell clonality. Three lymphomas were associated with Epstein-Barr virus. Two of four cases had an isochromosome 7q. Eleven patients are dead, eight within a year of diagnosis, and two patients have maintained complete remissions after combination chemotherapy. These data show that hepatosplenic T-cell lymphomas include an alphabeta-subtype. This group, along with the previously recognized gammadelta group, should be recognized as phenotypically heterogeneous subtypes of the same disease entity.     

Epstein-Barr virus negative clonal plasma cell proliferations and lymphomas in peripheral T-cell lymphomas: a phenomenon with distinctive clinicopathologic features

Clonal B-cell populations have been described in peripheral T-cell lymphomas (PTCL) as secondary Epstein-Barr virus (EBV) driven B-cell expansions that may evolve to an overt B-cell lymphoma. EBV-negative B-cell proliferations associated with T-cell lymphomas are uncommon and not well characterized. We studied 15 patients who developed an EBV-negative B-cell proliferation or malignant lymphoma associated with PTCL. The T-cell tumors were 8 PTCL, not otherwise specified, 4 angioimmunoblastic T-cell lymphomas, and 3 cutaneous PTCL. The B-cell component was intermingled with the PTCL in all patients and it was classified as clonal/monotypic plasma cell proliferation in 8 lesions, clonal/monotypic large B-cell proliferation in 4 patients, and B-cell lymphoma with plasmacytic/plasmablastic differentiation in 3 patients. Two patients had 2 clonally unrelated plasma cell proliferations associated with the same PTCL. All cases showed cytoplasmic Ig light chain restriction. Clonal IgH and T-cell receptor rearrangements were detected in 11/12 and 11/13 cases examined, respectively. EBV, cytomegalovirus, and HHV-8 were not observed in any of the examined cases. Sequential samples in 7 patients showed persistence of the PTCL and the B-cell component in 4, the PTCL without the B-cell lymphoma in 2, and progression of the B-cell neoplasm in 1. Patients followed an aggressive clinical course similar to conventional PTCL. In conclusion, EBV-negative clonal or mononotypic B-cell proliferations in patients with PTCL present with a spectrum of lesions ranging from plasma cell proliferations to overt lymphomas with plasmacytic/plasmablastic features. The distinctive features of these patients suggest that these lesions represent a specific phenomenon in PTCL.     

Primary cutaneous CD4+ small/medium-sized pleomorphic T-cell lymphoma expresses follicular T-cell markers

Cutaneous CD4 small/medium-sized pleomorphic T-cell lymphoma (CSTCL) is a cutaneous T-cell lymphoma defined by a predominance of small-to-medium-sized CD4 pleomorphic T cells, with a favorable clinical course. Cases are also characterized by the presence of a rich infiltrate of reactive B cells. Recently, it has been reported that follicular helper T cells (TFH cells) display a distinct gene expression profile, positive for PD-1, CXCL13, and BCL-6. We report for the first time the expression of PD-1 and other TFH cell markers in CSTCLs and discuss its biologic significance. Sixteen CSTCLs were included in this study, and also 20 reactive inflammatory conditions, 10 primary cutaneous marginal zone, 10 follicular center lymphomas, and 5 primary CD30 cutaneous lymphomas. They were immunohistochemically analyzed for a large panel of markers. Double immunoperoxidase labeling of paraffin sections was performed for PD-1, OCT-2, and BCL-6. Clonal Ig and T-cell receptor rearrangements and Epstein-Barr virus-encoded RNA expression were also evaluated. Morphologic and clinical data were reviewed. Histologic examination showed a dense polymorphic lymphoid infiltrate throughout the dermis. Atypical large CD4 cells were positive for PD-1, CXCL13, and BCL-6 in all cases, and were attached in small clusters, or formed rosettes around CD30/OCT-2+ B blast cells. Epstein-Barr virus was not apparent in any of the cases. A dominant T-cell clone was identified in 14 cases, whereas polymerase chain reaction IgH gene rearrangement studies showed that all cases were polyclonal. None of the patients had lymphadenopathy or showed any evidence of systemic disease, nor did they have any previous history of mycosis fungoides or drug reactions. FTH cell markers are not exclusive to angioimmunoblastic lymphadenopathy but may also be seen in neoplastic cells of CSTCLs. Moreover, these findings suggest that B-cell stimulation by FTH could also take place in some cutaneous T-cell lymphomas.     

The value of immunophenotyping on paraffin sections in the identification of T-cell rich B-cell large-cell lymphomas: lineage confirmed by JH rearrangement

Immunophenotyping of lymphomas using paraffin-embedded lymphoid tissue, not previously distorted by frozen section, is useful in identifying the large neoplastic B cells that may be in the minority in T-cell rich B-cell lymphoma (TCRBCL). Even in cases in which frozen tissue sections are available, the improved morphology in unfrozen sections allows the proper classification of these lymphomas as large cell and identifies their B-cell lineage, which is important for clinical therapeutic studies. Seven cases initially believed to be diffuse mixed cell lymphoma of possible peripheral T-cell lineage showed the large cells to be immunoreactive with L-26 (pan B-cell marker) with the majority of smaller lymphocytes immunoreactive for UCHL-1 and Leu-22 (pan T-cell markers). K/lambda immunostaining on frozen sections was equivocal. In these cases, the diagnosis of large-cell lymphoma of B-cell lineage was confirmed by detection of immunoglobulin heavy- (all seven cases) and light- (six of seven cases) chain gene rearrangements, with germ-line configuration of the T-cell receptor beta-chain gene (all cases). Some cases of TCRBCL may not show detectable rearrangement of the immunoglobulin genes because of the low concentration of neoplastic cells in the samples submitted. The presence of rearrangements in these seven cases, however, supports the diagnosis of TCRBCL based on paraffin immunophenotyping when frozen tissue is not available or when molecular studies are not feasible. Although these seven cases are classified as large-cell lymphoma, an intermediate-grade lymphoma, the influence of the reactive T-cell population on the clinical behavior will require follow-up studies.     

CD5 expression in B-cell small lymphocytic malignancies. Correlations with clinical presentation and sites of disease.

The authors examined the relationship between CD5 antigen expression and a nodal or extranodal presentation for three subtypes of low-grade non-Hodgkin's lymphoma: small lymphocytic (23 cases), small lymphocytic with plasmacytoid differentiation (10 cases), and lymphocytic lymphoma of intermediate differentiation (IDL) (29 cases). Antigen expression was studied by the avidin-biotin complex immunoperoxidase technique in frozen sections and correlated with expression of other B- and T-cell markers. Lack of CD5 expression was significantly associated with extranodal presentation among the over-all study group (p less than 0.001), as well as for those with small lymphocytic lymphoma and IDL, but not for those presenting with small lymphocytic lymphomas with plasmacytoid differentiation (p less than 0.21). Eleven patients presented exclusively with extranodal disease involving lung and respiratory tract, skin and subcutaneous tissue, salivary gland, stomach, conjunctiva, and uterus. All such lesions were CD5 negative and had been classified as small lymphocytic (four cases), small lymphocytic-plasmacytoid (four cases), and IDL (three cases). Retrospective review of these 11 cases demonstrated common histologic features described as characteristic of lymphomas of mucosa-associated lymphoid tissue (MALT). Two additional patients presented with disseminated nodal disease and involvement of gastrointestinal tract and oropharynx; both were CD5 positive. These findings support the concept that at least two antigenically distinct B-cell subpopulations may be involved in pathogenesis of low-grade small lymphocytic malignancies.     

Expression of CXCL13 by neoplastic cells in angioimmunoblastic T-cell lymphoma (AITL): a new diagnostic marker providing evidence that AITL derives from follicular helper T cells

Angioimmunoblastic T-cell lymphoma (AITL) represents a distinct entity among peripheral T-cell lymphomas (PTCLs). The cellular origin of AITL remains unknown, although a possible derivation from follicular helper T cells (TFH) has been suggested based on the CD4/Bcl-6 phenotype. It has been recently shown that expression of CXCL13, a chemokine critically involved in B-cell migration into germinal centers, is characteristic of TFH cells, as compared with other T helper subsets. We compared CXCL13 expression in 29 AITLs, 20 PTCLs, unspecified, 10 anaplastic large cell lymphomas (ALCL), and 4 other PTCLs. We showed that CXCL13 is expressed by AITL (29 of 29, 100%) and a subset of PTCL, unspecified (6 of 20, 30%), which all showed borderline features with AITL, but in only 1 of 10 (10%) ALCLs, and 0 of 4 other PTCLs. Two-color immunostainings further showed that CXCL13 was found in the cytoplasm of atypical CD5-positive T cells that expressed CD10. We conclude that CXCL13 expression is a common characteristic of AITL, which can help to delineate the morphologic spectrum of the disease, and further supports its derivation from TFH cells. CXCL13 expression may also provide an additional useful tool for the diagnosis of AITL.     

Cutaneous lymphomas with prominent granulomatous reaction: a potential pitfall in the histopathologic diagnosis of cutaneous T- and B-cell lymphomas

The presence of a granulomatous reaction in lesions of cutaneous lymphomas has been described in the past in several cases. Especially in mycosis fungoides, a "granulomatous" variant of the disease has been well characterized. We studied the clinicopathologic features of cutaneous lymphomas with prominent granulomatous reaction, including both cutaneous T-cell lymphomas and B-cell lymphomas (primary cutaneous lymphoma 22, secondary cutaneous lymphoma one). Biopsies of 23 patients with histopathologic features of cutaneous T-cell lymphoma or cutaneous B-cell lymphoma with prominent granulomatous reaction were included in this study. A prominent granulomatous reaction was defined as the presence of a granulomatous component exceeding 25% of the dermal infiltrate. There were 14 cases of mycosis fungoides, two of subcutaneous panniculitis-like T-cell lymphoma, four of small/medium pleomorphic T-cell lymphoma, one of follicle center cell lymphoma, one of large B-cell lymphoma, and one of secondary cutaneous peripheral T-cell lymphoma. Altogether, a prominent granulomatous reaction could be observed in 1.8% of all patients with cutaneous lymphoma (primary or secondary) registered in the files of the Department of Dermatology of the University of Graz (Graz, Austria), demonstrating that there is a distinct, albeit small, proportion of cases revealing this peculiar reaction pattern. In seven cases a misdiagnosis of granulomatous dermatitis preceded the correct diagnosis for a period of 1-216 months, suggesting that sequential biopsies and complete phenotypic and molecular genetic analyses should be carried out in cases of "unusual" granulomatous dermatitis.     

Follicular colonization in B-cell lymphoma of mucosa-associated lymphoid tissue

The formation of neoplastic B-cell follicles is universally accepted as diagnostic of a follicle centre cell (FCC) lymphoma. Low-grade B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) are characterized by a diffuse infiltrate of cells of uncertain lineage known as "centrocyte-like" cells because of their resemblance to centrocytes (small cleaved cells). Some MALT lymphomas, however, contain numerous follicles and may even have a predominantly follicular appearance. These follicles may be reactive or show immunoglobulin (Ig) light-chain restriction, indicating their neoplastic nature. We have proposed that these neoplastic follicles are not composed of follicle centre cells but result from colonization of reactive follicles by CCL cells. In this study, the immunophenotype and genotype of 10 primary gastrointestinal lymphomas with a follicular component have been determined. One case exhibited the morphological, immunophenotypic, and genotypic features of FCC lymphoma (Ig light-chain restriction, CD10+, KB61 (CDw32)-, Jh, and bcl-2 gene rearrangement). Neoplastic follicles in the remaining nine cases, which showed the features of MALT lymphoma, were of a different phenotype (Ig light-chain restriction, CD10- KB61(CDw32)+), and these lymphomas showed Jh but not bcl-2 gene rearrangement. Taken in conjunction with the morphological features, these findings suggest that in these cases the neoplastic follicles formed as the result of colonization of previously reactive follicles by neoplastic CCL cells. Thus, not all lymphomas containing neoplastic follicles are of FCC origin. Follicular colonization, as seen in low-grade MALT lymphomas, is likely to be a recapitulation of an as yet undescribed normal immunological phenomenon that may involve marginal zone B cells.     

T-cell signet-ring cell lymphoma. A histologic, ultrastructural, and immunohistochemical study of two cases

The histologic, ultrastructural, and immunologic characteristics of two signet-ring cell lymphomas of T-cell derivation are presented. Histologically, both lymphomas were diffuse large cell lymphomas with many neoplastic cells containing cytoplasmic vacuoles imparting a signet-ring configuration. Ultrastructural examination revealed the vacuoles to consist of electron-lucent spaces containing variable numbers of microspherules. Immunohistochemical studies showed that both lymphomas expressed T-cell phenotypes with no reactivity with antibodies to B-cell antigens. In contrast to previous reports which have shown signet-ring cell lymphomas to be invariably B-cell in derivation and usually follicular center cell type, this study demonstrates that these lymphomas may also be of T-cell origin.     

Frequency of Epstein-Barr viral DNA in "Western" sinonasal and Waldeyer's ring non-Hodgkin's lymphomas.

Sinonasal non-Hodgkin's lymphomas (SNHL) of B- or T-cell immunophenotype have been associated with the Epstein-Barr virus (EBV) in Asian patients. We investigated eight sinonasal and 10 Waldeyer's ring NHL from Western patients for evidence of EBV genomes using a sensitive in situ hybridization technique. EBV DNA was detected in each of three sinonasal NHL with a T-cell immunophenotype and two of five cases with a B-cell immunophenotype. Two of 10 B-cell Waldeyer's ring NHL were positive for EBV genomes. In each positive case, EBV genomes were evenly distributed among the neoplastic cells, whereas no evidence of EBV in associated nonneoplastic lymphocytes or epithelium was seen. The results indicate that B-cell and T-cell sinonasal NHL are associated with EBV in Western as well as in Asian patients, and that EBV may have a role in oncogenesis in NHL of the upper aerodigestive tract. The strong association of EBV with nasopharyngeal carcinoma suggests that the anatomic site is important in the development of EBV-related neoplasms.     

Primary extranodal soft tissue lymphoma of the extremities

Since true primary lymphomas of soft tissues are extremely rare and there are few well-documented cases in the literature, we report eight cases to help define the clinical and pathologic features of this type of extranodal lymphoma. Among 7,000 malignant lymphomas seen at Mayo Clinic over a 10-year period, we found eight cases of Stage IAE extranodal malignant lymphoma that presented as a soft tissue mass in the upper or lower extremities. The tumors occurred in the following sites: thigh (n = 4), upper arm (n = 2), ankle (n = 1), and calf (n = 1). Two cases had low-grade histology: small lymphocytic lymphoma and follicular mixed small-cleaved and large-cell lymphoma. An intermediate-grade histology was present in two cases: diffuse mixed small- and large-cell lymphoma and diffuse large-cell (cleaved) lymphoma. Half of the patients had a high-grade lymphoma: diffuse large-cell (n = 3) and large-cell, immunoblastic (n = 1). The results of immunohistochemistry and electron microscopy in selected cases are discussed in the context of the differential diagnosis with other small, round-cell cancers. Four patients died of recurrent lymphoma, one at 7 months, two at 15 months, and one at 4 years. Three patients are alive without evidence of disease at 3, 8, and 13 years. One patient is alive and is receiving chemotherapy for locally recurrent lymphoma 6 months after diagnosis.     

Sinonasal lymphoma: a clinicopathologic analysis of 58 cases from the Massachusetts General Hospital.

Few large series compare lymphomas of the nasal cavity with those of the paranasal sinuses. We studied the cases of 58 patients, 34 males and 24 females, aged 7 to 92 years (mean, 57 years), who had lymphoma involving the nasal cavity or paranasal sinuses. Thirty-three patients had diffuse large B-cell lymphoma (DLBCL). Twenty-three were male and 10 were female, with an age range of 7 to 91 years (mean, 63 years); two were HIV-positive. Only 2 of 11 cases tested (one in an HIV-positive patient and one of lymphomatoid granulomatosis type) were Epstein-Barr virus (EBV)-positive. Thirty (91%) involved paranasal sinuses, 10 with nasal involvement, whereas three cases had nasal, but not sinus, involvement. At last follow-up, 16 (67%) were free of disease 7 to 169 months later (mean, 65 months), and 8 (33%) had died of disease 2 to 166 months later (mean, 45 months). Seventeen patients had nasal-type natural killer (NK)/T-cell lymphoma. There were 10 women and 7 men, aged 27 to 78 years (mean, 48 years). Thirteen of 14 were EBV-positive. Sixteen patients had nasal involvement, eight with sinus involvement. Eleven (73%) of 15 were alive and well 6 to 321 months later (mean, 139 months), three (20%) died of lymphoma 1, 11, and 12 months later, and one (7%) is alive with disease. There was one case each of marginal zone B-cell lymphoma, Burkitt's lymphoma, Burkitt-like lymphoma, peripheral T-cell lymphoma of unspecified type, and adult T-cell lymphoma/leukemia. In an additional three cases, the lymphomas were composed predominantly of large cells, but no immunophenotyping could be performed for subclassification. In 19 cases (17 DLBCLs, 1 Burkitt-like lymphoma, and 1 lymphoma of uncertain lineage), presenting symptoms included complaints related to the eyes. In 16 cases (13 DLBCLs, 1 Burkitt-like lymphoma, 1 nasal NK/T-cell lymphoma, and 1 lymphoma of uncertain lineage), the orbit was invaded by lymphoma. In our series, the most common lymphoma to arise in the sinonasal area is DLBCL, followed by nasal NK/T-cell lymphoma. Comparison of these two types of lymphoma showed that lymphomas involving sinuses without nasal involvement were predominantly DLBCLs (20 of 21), whereas nasal cavity lymphomas without sinus involvement were usually NK/T-cell type (8 of 11) (p = 0.000125). Compared with patients with DLBCL, patients with nasal NK/T-cell lymphoma were overall younger, with a lower male-to-female ratio. Lymphomas of B-cell lineage were more likely to be associated with symptoms related to the eyes (p < 0.0005) and to have extension to the orbit (p < 0.01) than were lymphomas of T- or NK-cell lineage. In contrast to results of Asian studies in which nasal NK/T-cell lymphoma has a very poor prognosis, our nasal NK/T-cell lymphomas had an outcome similar to that of DLBCL.     

Malignant lymphoma involving the mandible. Clinical, morphologic, and immunohistochemical study of 17 cases

We present 17 cases of non-Hodgkin's lymphoma of the mandible, collected over a span of 10 years. Clinically, the patients showed a male:female ratio of 1:2.4 and a mean age of 60.6 years. Swelling was the most common symptom. In 11 of 17 patients, the disease presented in stage I. Radiotherapy alone was employed in 11 patients, in conjunction with chemotherapy in 5 patients, and was preceded by surgery in the remaining case. At this writing ten of the subjects are still alive, five died following progression of the disease, and two were lost during follow-up while in complete remission. Histopathology revealed 15 B-cell lymphomas (1 centroblastic/centrocytic, nine centroblastic, one Burkitt's, two immunoblastic, and two lymphoblastic) and two peripheral T-cell lymphomas (pleomorphic). The above diagnoses were confirmed by immunohistochemical analysis with a wide panel of reagents against fixative-resistant molecules. Our data suggest that (a) lymphomas of the mandible are principally represented by high-grade B-cell varieties (88%); (b) primitive T-cell lymphomas (here documented for the first time) have the same incidence in the mandible as they have in lymph nodes; and (c) immunohistochemistry, besides confirming histogenetic interpretations based on morphologic findings, provides the key to the differential diagnosis from malignant large-cell nonlymphoid tumors.     

Peripheral T-cell lymphoma with follicular involvement and a CD4+/bcl-6+ phenotype

A truly follicular pattern is thought to be restricted to B-cell lymphomas. We observed a prominent follicular growth pattern in three cases of nodal peripheral T-cell lymphomas, of which two were initially diagnosed as follicular lymphomas. All three patients were male, ranged in age from 50 to 70 years, and had generalized lymphadenopathy at the time of diagnosis. The follicles were sharply demarcated in two cases and large and vague in one case; in all cases, they contained abundant follicular dendritic cells. Neoplastic cells were small to medium, with irregular cleaved or round nuclei and clear cytoplasm, which was abundant in one case. Lymphoma cells in all cases were CD4+ CD8- CD57- bcl-6, with CD10 coexpression in 2 cases. Clonal rearrangement of the gamma chain of the T-cell receptor gene was demonstrated in each case. These cases expand the differential diagnosis of lymphomas with a follicular growth pattern and suggest that neoplastic T cells may have the capacity to induce or home to follicular structures.     

Reliable and cost-effective paraffin section immunohistology of lymphoproliferative disorders

We studied 110 neoplastic and reactive lymphoid proliferations with three monoclonal antibodies--CD20 (L26), CD43 (Leu22), and CD45RO (UCHL1)--on B5-fixed, paraffin-embedded tissue to evaluate the utility of this panel as an immunotypic screen of such lesions. All cases were initially immunotyped by conventional methods. Genotyping by Southern blot hybridization was also done in 54 cases. Seventy-four of 79 malignant lymphomas and both of two hairy cell leukemias were of B-cell origin; and five lymphomas were defined as T-cell lineage. Lineage assignment was identical for paraffin section immunohistology and conventional immunotyping in 73 of 76 B cell and all of five T-cell tumors. CD20 was reactive with 73 of 76 B-cell tumors. CD43 was reactive with 12 of 74 B-cell lymphomas, and CD20/CD43 coexpression was seen in 11 of these cases. CD43 and CD45RO marked all of five and three of five T-cell lymphomas, respectively. Lineage assignment was identical for paraffin immunohistology and genotyping in 48 of 50 cases with identifiable gene rearrangements. Twenty-four nonneoplastic and five Hodgkin's disease cases that were studied also showed similar immunoreactivity patterns by both paraffin and conventional immunotypic methods. This panel of three monoclonal antibodies is an efficient, cost-effective approach for immunotyping most lymphoid proliferations in paraffin sections. Nevertheless, the pathologist should always try to obtain fresh or frozen tissue to aid in resolving occasional discrepant cases, to establish clonality in morphologically ambiguous ones, and to profile prognostically important phenotypic deletions.     

Head and neck lymphoma in patients with the acquired immune deficiency syndrome.

A marked increase has recently been noted in the incidence of lymphoma in patients with AIDS. These lymphomas are generally high-grade, of B-cell origin, and often involve extranodal sites. Reported here are twenty patients with AIDS in whom symptoms and physical findings developed related to the head and neck region as a result of lymphoma. The tumor was observed in a variety of sites, including the nasopharynx, orbit, submandibular triangle, anterior and posterior cervical triangles, supraclavicular fossa, and the hypopharynx. Sixteen tumors were large cell nonHodgkin's B-cell lymphomas, three were small cell nonHodgkin's B-cell lymphomas, and one was Hodgkin's disease, mixed cellularity. All were treated with combination chemotherapy. A high degree of suspicion for lymphoma is required in treating any patient with AIDS who has a rapidly enlarging mass in the head and neck. If needle aspiration is nondiagnostic, excisional biopsy should be performed after a complete head and neck evaluation. Although the development of lymphoma associated with AIDS portends a grave prognosis, prompt diagnosis will allow an improved chance of remission of the lymphoma.