Immunohistological characterization of malignant lymphomas of the Waldeyer's ring other than the nasopharynx

Marginal zone lymphoma of palatine tonsil with prominent plasmacytic differentiation: A CARE-compliant article and review of literature

RATIONALE

The palatine tonsil is an important component of Waldeyer's ring and a site commonly involved by lymphoma. Interestingly, although it is a site of mucosa-associated lymphoid tissue (MALT), primary MALT lymphoma of the palatine tonsil is rare, especially with prominent plasmacytic differentiation.

PATIENT CONCERNS

A 59-year-old woman presented to the hospital with a 1-month history of odynophagia. The patient had no fever or pruritus during this period and she declared no family history of hematolymphoid malignancy.

DIAGNOSIS

Histopathological examination demonstrated effacement of tonsil architecture; normal follicles were replaced by plasmacytoid tumor cells and small lymphocytes. The tumor cells expanded the marginal zone and infiltrated interfollicular regions, as well as scattered residual follicles. Immunostaining showed tumor cells positive for cluster of differentiation (CD)20, CD79a, paired box-5, Mum 1, and B cell lymphoma (Bcl)-2, and negative for CD5, CD 23, cyclin D1, Bcl-6, and CD10. Staining for κ and λ showed prominent light chain restriction. The tumor was classified as tonsil MALT lymphoma with prominent plasmacytic differentiation.

INTERVENTIONS

After the patient was diagnosed with MALT lymphoma with prominent plasmacytic differentiation, she underwent complete surgical resection and radiotherapy.

OUTCOMES

There was no recurrence evident at 6-months follow-up.

LESSONS

Primary tonsil MALT lymphoma with prominent plasmacytic differentiation is very rare and difficult to distinguish from other B-cell lymphomas with plasmacytoid morphology, such as follicular lymphoma, lymphoplasmacytic lymphoma, and chronic lymphocytic leukemia/small lymphocytic lymphoma. Accurate diagnosis of this entity is important in guiding therapy so as to avoid overtreatment.

Hodgkin lymphoma involving extranodal and nodal head and neck sites: characteristics and outcomes

BACKGROUND

Most Hodgkin lymphoma (HL) patients present with disease in nodal regions. However, in a small subset, disease develops in unique anatomic sites such as the head and neck area. This study aims to identify the characteristics and outcomes of patients who develop HL involving extranodal and nodal head and neck sites.

METHODS

The authors searched The University of Texas M. D. Anderson Cancer Center's database for HL patients treated between 1967 and 2007 and included those with HL at head and neck sites. They reviewed the records for site of involvement, pathology, treatment, and survival.

RESULTS

The authors identified 39 patients with extranodal and nodal HL of the head and neck. Five patients with lymphocyte predominant HL were excluded. Specifically, 10 of 34 patients had disease in the tonsils, 9 in the nasopharynx, 8 in the thyroid, 3 in the parotid, 2 in the adenoids, and 1 each in Waldeyer's ring and nasal antrum. Median age at diagnosis was 31.5 years, average age at diagnosis was 38 years, and 22 of 34 were male; 23 had stage I or II disease. Pathologically, 14 of 34 had the nodular sclerosis subtype, whereas 15 had mixed cellularity. Twenty-nine of 34 had nodal neck disease at presentation. Five of 34 received chemotherapy alone, 5 received radiation alone, and 24 received combination therapy. Twenty-one of 34 received 39.6 gray of external beam radiation. The most commonly used chemotherapy regimens were ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) and MOPP (mechlorethamine, vincristine, procarbazine, and prednisone). At last follow-up, 85% were disease-free.

CONCLUSIONS

HL of the head and neck is primarily diagnosed as early stage disease of men and of young to middle-aged individuals. Chemotherapy and primary/adjuvant radiotherapy offer excellent local and systemic control. The extent to which nodal disease is present in the neck does not alter outcomes when combined modality therapy is offered. Despite the unique anatomic location of these lesions, standard HL protocols work effectively to promote disease-free survival.

Marginal Zone B-Cell Lymphoma Among Primary B-Cell Lymphoma of Waldeyer's Ring: Histopathologic and Immunohistochemical Study of 16 Tonsillectomy Specimens

Two subtypes of marginal zone B-cell lymphoma (eg, mucosa-associated lymphoid tissue [MALT] type and splenic type) have been reported in the lymph node. To determine the presence or absence of marginal zone B-cell lymphoma of MALT type and the splenic type among Waldeyer's ring (WR) lymphomas, 16 tonsillectomy specimens were studied. Ten cases (63%) were marginal zone B-cell lymphoma. Among marginal zone B-cell lymphoma, 7 were the MALT type and the remaining 3 cases of marginal zone B-cell lymphoma were the splenic type. Moreover, 4 cases of 7 MALT-type lymphomas contained numerous large cells (diffuse large B-cell lymphoma arising from a low-grade marginal zone B-cell lymphoma of MALT type). The low incidence of primary mucosa-associated lymphoid tissue type lymphoma of WR in previous reports may be because it is difficult to correctly identify the characteristic histologic findings of MALT-type lymphoma because of the small biopsy size.

Tumour biological aspects of CD24, a mucin-like adhesion molecule

CD24 is a molecule that recently has raised considerable attention in tumour biology. It is involved in cell adhesion and metastatic tumour spread. It has also been described as a new diagnostic marker of tumours, of neuroendocrine differentiation and, possibly most intriguing of all, of patient prognosis. High rates of CD24 expression detected by immunohistochemistry have been found in epithelial ovarian cancer (83%), breast cancer (85%), non-small cell lung cancer (45%), prostate cancer (48%) and pancreatic cancer (72%). With the exception of pancreatic cancer, high rates of CD24 are significantly associated with a more aggressive course of the disease, a finding that remains significant in a multivariate analysis. The aim of this review is to summarize relevant work covering these aspects of CD24.

Tumour biological aspects of CD24, a mucin-like adhesion molecule

CD24 is a molecule that recently has raised considerable attention in tumour biology. It is involved in cell adhesion and metastatic tumour spread. It has also been described as a new diagnostic marker of tumours, of neuroendocrine differentiation and, possibly most intriguing of all, of patient prognosis. High rates of CD24 expression detected by immunohistochemistry have been found in epithelial ovarian cancer (83%), breast cancer (85%), non-small cell lung cancer (45%), prostate cancer (48%) and pancreatic cancer (72%). With the exception of pancreatic cancer, high rates of CD24 are significantly associated with a more aggressive course of the disease, a finding that remains significant in a multivariate analysis. The aim of this review is to summarize relevant work covering these aspects of CD24.

Detection of germinal center B-cell lymphoma in archival specimens: critical evaluation of Bcl-6 protein expression in diffuse large B-cell lymphoma of the tonsil

Expression of Bcl-6 and CD10, markers for the tumor of the germinal center (GC) B-cell derivation, has been studied in primary diffuse large B-cell lymphomas (DLBCLs) of the lymph node, gastrointestinal tract, and mediastinum. In these studies, the coexpression rate of CD10 and Bcl-6 was relatively constant at 30% approximately 40%, but the frequency of Bcl-6+ tumors varied from 55% to 100%, raising doubts about the usefulness of Bcl-6 expression in identifying the tumor of GC B-cell derivation. Because the expression of Bcl-6 in tumors of non-GC B-cell origin has recently been reported, we critically evaluated the expression of Bcl-6 and CD10 in primary DLBCLs of the tonsil, a relatively common tumor in Japan and Korea. The cases (n = 51) represented a consecutive series for any recent 2-year period at several teaching hospitals in Korea and Japan. Formalin-fixed, paraffin-embedded specimens were used for immunostaining. Staining for Bcl-6 and CD10 was positive in 44 (86%) and 22 cases (45%), respectively. However, among those positive for Bcl-6 (>10% Bcl-6+ tumor cells), 2 basic patterns were recognized: uniform and nonuniform. The uniform pattern was characterized by a dense population (>75%) and a consistent density in any given area, resembling the staining pattern observed in GC or follicular lymphoma (FL) (the "GC/FL" pattern). In contrast, the nonuniform pattern exhibited a varying density from area to area, as well as a less-dense population (<75%). The uniform pattern was observed in 26 cases (51%). All but 1 (95%) of the CD10+ tumors coexpressed Bcl-6, with most (82%) displaying the uniform pattern. We conclude that tumors showing a uniform pattern of Bcl-6 expression should be distinguished from those showing a nonuniform pattern, because the former most likely represent tumors of GC B-cell derivation and the latter most likely represent tumors of non-GC derivation. GC B-cell lymphoma thus defined accounted for 51% of tonsillar DLBCL, a proportion comparable to that of the nodal DLBCL. CD10 expression correlated with the "GC/FL" pattern, but appeared to be not essential for the identification of GC B-cell lymphoma. This study suggests that a significant proportion of tonsillar DLBCLs in Asia is of GC B-cell origin rather than of mucosa-associated lymphoid tissue origin. This finding may have significance for clinical management of these lymphomas.

Focal follicular features in tonsillar diffuse large B-cell lymphomas: follicular lymphoma with diffuse areas or follicular colonization

Focal follicular features in diffuse large B-cell lymphomas (DLBCLs) are bound to raise the question of follicular lymphoma (FL) with diffuse areas, because the diagnosis of FL is based on the presence of follicular areas, even though focal. We report 7 cases of primary tonsillar DLBCLs with focal follicular features that presented with morphologic, immunohistochemical, and biological features distinct from those of FL. Histologically, these tumors were characterized by involvement of pericryptal follicles with adjacent dominant diffuse areas. Monomorphous large tumor cells were evenly spaced with abundant, often clear cytoplasm, and blastoid nuclei often with a delicate nuclear membrane. Importantly, residual germinal centers (GCs) were present in the form of either an intrafollicular GC remnant or an isolated GC in the midst of diffuse tumor. An extrafollicular and/or parafollicular growth pattern was also observed. Bcl-6 staining revealed a predominantly sporadic occurrence of Bcl-6(+) cells, comprising <50% of tumor cells, and none displayed diffusely dense collections (>75%) of Bcl-6(+) tumor cells characteristic of the GC or FL. Staining for CD10 was negative in 6 cases. Five of 7 patients were younger than 60, the median age of other patients with primary tonsillar DLBCL. No extratonsillar involvement was seen at 18 months after diagnosis. After chemotherapy or radiotherapy, complete remission was achieved with ease in all patients, but 2 patients who were treated with chemotherapy alone relapsed at 24 and 30 months. In conclusion, tonsillar DLBCL includes a small (10%) but distinct subgroup that warrants distinction from FL with predominant diffuse areas or de novo DLBCL. It appears that the focal follicular features in tonsillar DLBCL likely represent follicular colonization of marginal zone B-cell lymphoma, probably high-grade, if the possibility of FL is excluded.

Marginal zone B cell lymphomas of Waldeyer's ring--a report of two tonsillectomy cases resembling histomorphological features of inflammatory lesions

We identified two cases of lymphoma of the mucosa-associated lymphoid tissue (MALT) type in 11 tonsillectomy specimens of primary B cell lymphoma of Waldeyer's ring. Both patients were Japanese females presenting with bilateral enlargement of the palatine tonsils. One had a history of chronic otitis media. In that case, the lesion was characterized by an extrafollicular growth pattern with marginal zone-like arrangement. The tumor was mainly composed of medium-sized cells with round or indented nuclei with scant cytoplasm (centrocyte-like cells). In the other patient, most tumor cells were mature plasma cells, plasmacytoid cells, proplasmacytes, and immunoblasts with scattered centrocyte-like cells. Tropism of tumor cells for the epithelium was noted in both lesions. Primary marginal zone B cell lymphoma of the MALT type arising from Waldeyer's ring has rarely been reported in the literature, causing certain diagnostic problems. Various florid reactive lymphoproliferative disorders, including chronic tonsillitis and infectious mononucleosis, should be differentiated from this type of primary Waldeyer's ring lymphoma.

Waldeyer's ring lymphomas: a clinical study from the Comprehensive Cancer Center West population based NHL registry

It is debated whether non-Hodgkin's lymphomas originating in Waldeyer's ring (WR NHL) behave as NHL originating in lymph nodes or share common features with extranodal lymphomas originating in mucosa associated lymphatic tissue (MALT). We analyzed data from a population based NHL registry on patterns of dissemination at diagnosis, response to treatment, patterns of failure and survival of 77 primary Waldeyer's ring Non-Hodgkin's lymphomas (WR NHL) patents. Data of completely staged patients with diffuse large cell lymphomas (DLCL) originating in WR (n=44) were compared with those of patients retrieved from the same registry with DLCL originating in lymph nodes or stomach (the latter as prototype of a lymphoma originating in MALT). Primary WR NHL had favorable risk scores according to the International Prognostic Index (IPI), and responded well to therapy: a complete response (CR) rate of 74% was observed. Disease free survival (DFS) and overall survival (OS) were poor, however (47% and 31% at 10 years, respectively). The comparison of DLCL originating in WR, lymph nodes and stomach revealed that WR and gastric NHL patients shared a restricted pattern of dissemination at diagnosis, in contrast to patients with DLCL originating in lymph nodes. Although not all patients were completely restaged at relapse, analysis of patterns of failure suggested that the gastro-intestinal tract is a preferential site for recurrences, both for WR and gastric DLCL patients. CR rates of WR, nodal and gastric DLCL patients were 77%, 55% and 55% respectively (P=0.03), OS of the three patient subgroups did not differ (33%, 27% and 37% at 10 years). DFS of WR DLCL patients was similar to nodal DLCL patients but inferior to gastric DLCL patients (47%, 48% and 73% at 10 years respectively, P=0.006). After Cox regression analysis the relative relapse risk for patients with WR DLCL when compared to patients with DLCL originating in lymph nodes was 2.01 (C.I. 0.99-4.01, P=0.05), and 3.46 (C.I. 1.32-9.00, P=0.01) when compared to patients with gastric DLCL. The clinical picture of primary WR NHL emerging from this population based study is in agreement with data form hospital based studies. In the comparison of WR DLCL, nodal DLCL and gastric DLCL, the observed patterns of dissemination suggest similarities between WR DLCL and gastric DLCL. The frequent relapses after CR observed for WR DLCL patients, however, indicate that these lymphomas clinically behave as nodal DLCL, and should be treated accordingly.

Primary Adenoidal Hodgkin's Disease: Report of a Case with an Unusual Morphology and Review of the Literature

The nasopharyngeal lymphoid tissue (adenoids) is an uncommonly reported primary site for Hodgkin's disease. We report a case of primary adenoidal, interfollicular, epithelioid cell-rich variant of mixed cellularity Hodgkin's disease. The combination of an interfollicular pattern and richness of epithelioid histiocytes made it very difficult to make the diagnosis of Hodgkin's disease without the help of immunohistochemistry. To our knowledge, only 39 cases of Hodgkin's disease primarily involving the Waldeyer's ring have been reported in the English literature, 24 of these primarily involving the adenoids. Our case shows the difficulty encountered in making the diagnosis when a very unusual morphologic appearance of Hodgkin's disease is seen at a rare presentation site. The appropriate immunohistochemical work-up should be performed in unusual lymphohistiocytic proliferations involving the Waldeyer's ring. Int J Surg Pathol 8(3):241-246, 2000

CD-30 positive peripheral T-cell lymphoma of the Waldeyer's ring

We describe a patient with peripheral T cell lymphoma of the Waldeyer's ring that ran a highly aggressive course. This is followed by a discussion on the differential diagnoses of nasal T/NK cell lymphoma and Ki-1 ALCL, based on clinical and pathological features.

Primary nasal and nasopharyngeal lymphomas: a comparative study of clinical presentation and treatment outcome

Primary nasal lymphoma (NSL) and nasopharyngeal lymphoma (NPL) are uncommon extranodal lymphomas that have often been grouped together in studies published in the literature. It is unclear whether or not NSL and NPL are biologically different entities. We reviewed the records of 25 NSL and 19 NPL patients who were managed between 1985 and 1995, to evaluate and compare their clinical characteristics and treatment outcome. Clinical variables, including age, sex, stage, tumour bulk and treatment modality, were assessed for their prognostic influence on survival. Nasal obstruction (80%), nasal discharge (64%) and epistaxis (60%) were the predominant symptoms in NSL patients; neck swelling/mass (42%), nasal obstruction (37%) and hearing impairment (32%) were common findings in NPL patients. Limited stage disease (I/II) was present in all NSL and in 80% of the NPL patients. Thirty-six per cent of the NSL and 32% of the NPL patients had bulky disease. The majority of the immunophenotyped NSLs were of T-cell lineage (75%, 12/16) and most immunophenotyped NPLs were of B-cell lineage (69%, 11/16). The patients were treated with radiotherapy alone (14%), chemotherapy alone (23%) or chemotherapy plus radiotherapy (64%). NSL patients showed a lower complete remission rate and higher relapse rate than NPL patients, although the difference did not reach statistical significance. Both the 5-year disease-free survival (36% versus 76%; P = 0.007) and overall survival (33% versus 82%; P = 0.003) were significantly worse in NSL compared with NPL patients. Advanced age (>60 years; P = 0.03) and bulky disease (P = 0.04) were also associated with inferior survival times. The analysis of sex, stage and type of therapy showed no evidence of significant impact on the survival. Despite the close anatomical relationship in origin, NSL and NPL were noted to behave as biologically distinct entities, in which the NSLs demonstrated a higher frequency of T-cell tumours and a much worse prognosis than NPL. In addition to the primary site, advanced age and bulky disease were also associated with reduced survival.

Nasopharyngeal carcinoma

Nasopharyngeal carcinoma represents a morphologic spectrum of neoplasms localized to the nasopharynx and arising from nasopharyngeal epithelium. Nasopharyngeal carcinomas have rather unique clinical, epidemiologic, pathologic, and biologic features. The morphologic spectrum of nasopharyngeal carcinoma includes keratinizing, nonkeratinizing, and undifferentiated subtypes. The separation of these morphologic types is not an academic exercise, but has practical importance relative to differential diagnosis, management, and prognosis. A similar morphologic classification applies to carcinomas arising in the palatine tonsils and the base of tongue. The nasopharynx, palatine tonsils, and base of tongue are collectively designated as Waldeyer's tonsillar tissues. Awareness of the morphologic spectrum of Waldeyer's ring carcinomas may assist in suggesting the primary tumor site in the face of an occult metastatic carcinoma to cervical neck lymph nodes.

Unilateral tonsillar enlargement and tonsillar lymphoma in children

The clinical presentation and surgical and pathological findings of 46 children with unilateral tonsillar enlargement (UTE; age range 2 to 13 years, mean age 6.5) who underwent tonsillectomy for biopsy purposes between 1975 and 1995 were compared with those of 7 children who received treatment for tonsillar lymphoma (TL; age range 2 to 9 years, mean age 4.8) during the same period. There was no history of rapid tonsillar enlargement in children in the UTE group, and only 20 (43%) were symptomatic. Symptoms included recurrent sore throats in 10 patients (22%), snoring in 5 (11%), nasal obstruction in 4 (9%), and dysphagia in 1 (2%). No children had systemic symptoms or significant cervical lymphadenopathy. In contrast, tonsillar enlargement was observed to occur within a 6-week period in all children with TL, and 6 (86%) children had symptoms at presentation that included dysphagia in 5 (71%), snoring in 3 (43%), night sweats in 2 (29%), and fever and rigors in 2 (29%). Cervical lymphadenopathy greater than 3 cm was present in 6 (86%) children, while 1 child (14%) had hepatosplenomegaly. There was no histopathologic evidence of neoplasia in the UTE group, and a true discrepancy in size between the two tonsils was confirmed in only 21 of 44 (48%) cases. All 7 patients in the TL group had non-Hodgkin's lymphoma. All received chemotherapy, with 5 of the 7 cured and 2 dying of disease. The data suggest that tonsillectomy should be performed for biopsy purposes in UTE where there is a history of progressive enlargement, significant upper aerodigestive tract symptoms, systemic symptoms, suspicious appearance of the tonsil, cervical lymphadenopathy, or hepatosplenomegaly. The diagnosis of TL should also be considered when UTE is present in an immunocompromised child or one with a previous malignancy, when acute tonsillitis is asymmetric and unresponsive to medical treatment, or when rapid bilateral tonsil enlargement occurs. Observation is appropriate management for other cases of UTE.

Involvement of the tongue by lymphomatoid papulosis

We report on a case of lymphomatoid papulosis (LyP) with involvement of the tongue. The patient was a 34-year-old Japanese man. Three reddish, centrally depressed, slightly elevated nodules were evident on the dorsal tongue, along with lesions elsewhere on the skin. One of them was biopsied and exhibited a superficial and deep, perivascular and interstitial mixed cellular infiltrate including atypical lymphoid cells, lymphocytes, neutrophils, and histiocytes. The patient also showed rhythmical recurrence of reddish papules and ulcerated nodules on the trunk, extremities, and anogenital area. Histologically, these papules showed a dense, wedge-shaped mixed cellular infiltrate in the dermis, which included medium and large atypical lymphoid cells, lymphocytes, neutrophils, and histiocytes. Immunoperoxidase staining for CD30 was positive in the cell membrane and cytoplasm of the atypical cells. We could not find other reports of LyP involving the tongue. Systemic treatment with interferon (INF)-alpha2a was dramatically effective in inhibiting recurrence of the eruption.

The Epstein-Barr virus in malignant non-Hodgkin's lymphoma of the upper aerodigestive tract

Sixty malignant non-Hodgkin's lymphomas originating in the upper aerodigestive tract have been analyzed for their cytologic type, immunophenotype and association with the Epstein-Barr virus (EBV). The majority of these tumors were B-cell lymphomas of blastic cytology (78%) with the exception of lymphomas in the parotid gland. Large B-cell lymphomas were the most frequent encountered in the sinonasal region and Waldeyer's ring. Twelve lymphomas were of T- or T/NK (natural killer)-cell lineage. They were in the nasal cavity and the paranasal sinuses (4), the tonsil (5), and the oral cavity (3). Epstein-Barr sequences were detected in five angiocentric T/NK-lymphomas, one peripheral T-cell lymphoma, one lymphoma of lymphomatoid granulomatosis type, one large B-cell lymphoma, and in a lymphoroliferative disorder in an HIV-positive patient. These results suggest that EBV is not involved in lymphomagenesis of B-cell tumors, but is associated with angiocentric T/NK-cell lymphoma in the upper aerodigestive tract.

Nasal T/NK cell lymphoma: a clinico pathologic study of 30 west Chinese patients with special reference to proliferation and apoptosis

Midfacial T-cell lymphomas are more prevalent in Asia than in Europe or North America. Clinically, these lymphomas are noted as one major differential diagnosis in the malignant midline granuloma syndrome. During the past years, the group of nasal T/NK cell lymphomas has been recognized that is frequently associated with EBV-infection. The aim of the current publication was to describe the clinical presentation and course of 30 patients attending the West China University of Medical Sciences, Chengdu, P.R. China, between 1991 and 1994. Clinical records were assessed and the patients were followed for 6 to 29 (mean 12.4) months. Several microscopic features thought to be associated with this entity were carefully evaluated together with immunohistochemical data. The proliferation of the tumour cells was assessed by determining the mitotic index and the ratio of MIB-1 labelled cells. In addition, the incidence of apoptotic cells was investigated by means of the in-situ end labelling (ISEL) technique. Our data confirm the expression of T-cell markers by T/NK cell lymphomas as determined by the immunohistochemistry. The apoptotic index was found to correlate with the ratio of MIB-1 labelled cells. Expression of the bcl-2 oncoprotein was not associated with increased or diminished proliferation or cell death, respectively. Eight of the thirty patients succumbed to their disease during the follow-up period. Kaplan-Meier cumulative survivals and log-rank tests revealed a significant impact of MIB-1 labelling on mean survival times.

Low-grade B-cell lymphoma of mucosa-associated lymphoid tissue type in Waldeyer's ring

Amongst a total of 329 cases of low-grade B-cell lymphoma of Waldeyer's ring, we identified 12 cases that corresponded histomorphologically to low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type. These lymphomas are characterized by an extrafollicular growth pattern, often with a marginal zone-like arrangement, and by the centrocyte-like morphology of the tumour cells. They have not been described previously in this location. They predominantly affected the palatine tonsil. Ten cases were primary lymphomas of Waldeyer's ring. In two cases there was a simultaneous high-grade component. Two cases showed regional spread to cervical lymph nodes, but there was no widespread nodal involvement at the time of diagnosis. Immunohistochemically, all cases displayed B-cell markers and light chain restriction. Tropism of tumour cells for the epithelium was a consistent finding. In two cases involvement of Waldeyer's ring was secondary; in one of them the primary tumour was a gastric low-grade B-cell lymphoma of MALT type and in the other a high-grade B-cell non-Hodgkin's lymphoma of the stomach. These findings indicate that low-grade B-cell lymphomas of MALT type occurring in Waldeyer's ring should be included amongst the tumours of the MALT system. We surmise that in Waldeyer's ring such tumours are derived from the marginal zone, as has already been postulated for similar gastric tumours.

Waldeyer ring lymphomas. A clinicopathological study of 79 cases

Waldeyer ring lymphomas belong to a category of tumours which has not yet been fully defined. Their relation to mucosa-associated lymphoid tissue (MALT) and other extranodal lymphomas remains largely unknown. We performed a clinicopathological retrospective study of 79 patients, and compared them with a series of MALT and nodal lymphomas. Tumours from the nasopharynx and palatine tonsil showed similar histological profiles, with a predominance of large B-cells. Centroblastic lymphomas constituted the largest group (n = 45), followed by those of centrocytic type (9) with smaller groups of centroblastic-centrocytic (5) and Hodgkin's lymphomas (2). Three monocytoid B-cell lymphomas were identified. Only one case could be classified as MALT lymphoma. The frequency of bcl-2 expression in large B-cell tumours of Waldeyer's ring has an intermediate range between large B-cell lymphomas occurring in mucosal and nodal locations. Epitheliotropism was present in all low-grade cases, and was therefore not a useful marker in the identification of potential MALT lymphomas in contrast with other mucosal sites. Comparative survival studies showed significant overall differences between Waldeyer ring lymphomas, MALT and nodal cases. These disappeared after taking stage and histological grade into account. We conclude that Waldeyer ring lymphomas show distinctive features, mainly in terms of histological distribution and immunophenotype. The key factor determining their behaviour could be their different spreading capability. These findings suggest that extranodal lymphomas are heterogeneous, and indicate the need for additional efforts to clarify this.

Malignant lymphoma of Waldeyer's ring. A histological and immunohistochemical study

The histopathological and immunohistological features of non-Hodgkin's lymphoma limited to the Waldeyer's ring were studied in 22 Japanese patients using a panel of T- and B-cell markers on paraffin-embedded sections. All cases showed a diffuse growth pattern. Twenty cases were B-cell lymphomas and two were T-cell lymphomas. In contrast to the primary malignant lymphomas of the nasal cavity and paranasal sinuses, in which T-cell neoplasms are more frequently seen, the majority of the primary Waldeyer's ring lymphomas were B-cell neoplasms. Sixteen of the 20 cases of B-cell lymphoma were centroblastic lymphomas, and the monomorphic variant comprised the majority of these; the other three B-cell lymphomas were immunocytomas. Two of the T-cell lymphomas showed morphological features of angiocentric lymphomas.

Human tonsil intraepithelial B cells: a marginal zone-related subpopulation

AIMS

To determine if intraepithelial B cells in reactive human palatine tonsils were similar to the marginal zone cells of the spleen and Peyer's patches.

METHODS

Reactive human palatine tonsils were studied using conventional methods of light microscopy, electron microscopy, and a panel of monoclonal antibodies for leucocyte common antigens.

RESULTS

Clinically important numbers of marginal zone-related B cells around the mantle zone were absent in lymphoid follicles, but in the cryptal epithelium there were abundant lymphoid cells with centrocyte-like nuclei and clear cytoplasm, intermingled with macrophages and plasma cells. The immunophenotype of these intraepithelial B cells was distinctive and similar to that found in the splenic marginal zone cells (IgM+, IgD-, CD23-, CD10-, CD35+, CD21+, bc12+, KB61+).

CONCLUSIONS

Intraepithelial B cells in human tonsil could represent the counterpart of the marginal zone described in Peyer's patches. Their presence within the epithelium could reflect the destination for the malignant B cells in the lymphoepithelial lesion of mucosa associated lymphoid tissue (MALT) lymphomas. Human palatine tonsil lymphoid tissue has morphological, immunophenotypic, and pathological features similar to those of MALT.

Nasopharyngeal and nasal malignant lymphoma: a clinicopathological study of 54 cases

Forty-one cases of nasopharyngeal and 13 cases of nasal malignant lymphoma have been examined histologically and immunohistochemically. All of the cases were non-Hodgkin's lymphoma; one case was of follicular type and the remaining 53 were of diffuse type. Large cell lymphoma comprised 48% of cases and most of the immunoblastic lymphomas showing pleomorphism occurred in the nose. Twenty-seven cases were of T-cell and 21 of B-cell phenotype. The predominance of T-cell lymphoma was due to an increased incidence of these in the nose, the T:B ratio of 3.33:1 contrasting with a 1:1.05 ratio in the nasopharynx. Nasopharyngeal lymphomas seem to show an intermediate incidence between the T-cell predominance in the nose and a B-cell predominance in the oropharynx. Since the large cell type of lymphoma was predominant, the differential diagnosis from undifferentiated carcinoma is important and is facilitated by the use of immunostaining methods.

Extranodal oral lymphomas: histologic subtypes and immunophenotypes (in routinely processed tissue)

Twenty-seven extranodal oral lymphomas were subclassified according to the National Institutes of Health International Working Formulation. Immunophenotypes were then determined by means of an ABC technique with newly generated antibodies that identify fixation-resistant antigens on lymphoid cells. Diffuse small and large cell lymphomas were the most frequently identified subtypes. B-cell-associated antibody, L26, stained a majority of tumor cells in all lymphomas. Although 4KB5 was a less consistent B-cell marker, it stained most lymphomas. Reactive T-cell infiltrates, identified with antibodies MT1, UCHL-1, anti-CD3, and OPD4, varied from slight to intense. MT1 occasionally showed cross-reactivity with neoplastic B cells. No "histiocytic" lymphomas were found, but reactive macrophage infiltrates were identified in many lymphomas with monoclonal antibody KP1. In view of the immunohistochemical results, all lymphomas were believed to be of B-cell origin. Although antibody panels of the type used in this study can be effective in subtyping routinely processed oral lymphomas, careful interpretation is required because of reactive T-cell infiltrates.

Clinicopathological features and prognostic factors in extranodal non-Hodgkin lymphomas. Danish LYFO Study Group

In a Danish population-based non-Hodgkin lymphoma (NHL) registry, 1257 newly diagnosed NHL cases were registered over a 5-year period. Of these, 463 (37%) were extranodal. The gastrointestinal tract was the most common site of extranodal involvement (30% of the cases). Histologically, 44% of all extranodal NHL cases had high-grade, 17% intermediate and 27% low-grade features, while 12% were unclassified. The most common histological subtype (Kiel) was the centroblastic diffuse (23% of cases). 50% of all extranodal NHL were localised (stage IE or IIE) and 27% had B symptoms. Site-specific features included a strong age-correlation for thyroid and testes lymphoma (greater than 50 years) and a high prevalence of female cases in thyroid and salivary glands lymphomas (M/F 0.14 and 0.30, respectively). Overall 7-year survival for extranodal NHL was 46% (median 4.9 years). Poor prognosis patients could be identified by the presence of one or more of the following presentation characteristics: age greater than 65 years, B symptoms, high-grade histology, disseminated disease, elevated s-IgA and hyperuricaemia. Relative risk values ranged from 2.1 for age and B symptoms to 1.7 for hyperuricaemia.

Sinonasal non-Hodgkin's lymphomas and Wegener's granulomatosis: a clinicopathological study

Reports of sinonasal non-Hodgkin's lymphomas, analysed with monoclonal antibodies, are scarce, and differentiation of these lymphomas from Wegener's granulomatosis can be difficult. In this study, we investigated histopathologically and immunohistologically 20 cases of non-Hodgkin's lymphoma, primary in the sinonasal region, and sinonasal biopsies from 11 patients with Wegener's granulomatosis. All T-cell lymphomas (n = 7) and plasmacytomas (n = 4) were stage I at clinical presentation, while all B-cell lymphomas (n = 9) presented at higher stages. T-cell lymphomas tended to be more frequent in the nasal cavity and paranasal sinuses; B-cell lymphomas more often presented in the nasopharynx. Remarkably, 1 B-cell lymphoma expressed MT1, and 1 T-cell lymphoma expressed L26 (CD 20). The follow-up of 2 patients with a clinical diagnosis of Wegener's granulomatosis was suggestive of non-Hodgkin's lymphoma. Retrospective immunohistochemical analysis revealed that the original histological diagnosis of non-specific inflammation had to be changed to T-cell lymphoma, pleomorphic small cell type. We conclude that a biopsy from the sinonasal region with a dense inflammatory infiltrate, consisting predominantly of T-lymphocytes, renders a diagnosis of Wegener's granulomatosis unlikely and is at least suspicious of T-cell lymphoma. Immunohistochemical analysis is warranted for this type of biopsy.

Extranodal non-Hodgkin's lymphoma of the head and neck. A clinicopathologic study in the Kyoto-Nara area of Japan

The clinicopathologic features of 114 Japanese patients with extranodal non-Hodgkin's lymphoma of the head and neck region were analyzed. The median age was 60.5 years and the male:female ratio was 1.5:1. The most common site of involvement was Waldeyer's ring, followed by the oral cavity, thyroid gland, paranasal sinuses, nasal cavity, and larynx. Seventy-five percent of the patients were in Stage I or Stage II at admission. Histologically, diffuse lymphoma accounted for 94% and follicular lymphoma for 6% of cases. The histologic grade according to the Working Formulation System of the National Cancer Institute was low in 11%, intermediate in 75%, and high in 14% of cases. Immunohistochemical study showed that the majority of the cases were of B-cell type and only 13 cases (11%) were of the T-cell type. Peripheral T-cell lymphomas (eight cases) mainly occurred in the nasopharynx and nasal cavity, whereas four of five thymic T-cell lymphomas were found in the palatine tonsil. The over-all 5-year survival rate was 54%, and the factors affecting survival were sex, histologic grade, T/B phenotype, clinical stage, and the site of initial presentation. Five-year survival with nasal cavity and Waldeyer's ring lymphoma was 24% and 46%, respectively. The poor prognosis of lymphomas at these sites might result from the predominance of T-cell lymphoma, the paucity of low grade lymphoma, and the relatively high incidence of cases that were in an advanced stage at presentation. In Stage II, patients treated with combined therapy tended to have a better 5-year survival rate than those treated with radiotherapy alone.

Large B-cell lymphomas with a high content of reactive T cells

Twenty-one cases of large, B-cell lymphoma with an unusually high content of reactive T lymphocytes are described in this report. Fifteen patients presented with lymphoma in nodal sites and six patients presented with lymphoma in extranodal sites. With two exceptions, all patients were more than 50 years of age. The male to female ratio was 1:2. Histologically, isolated to small groups of large lymphoid cells were intermingled with many small lymphocytes. The large cells were neoplastic and exhibited B-lineage markers; immunoglobulin light chain restriction could be demonstrated in two thirds of the cases. There was a rich infiltrate of immunophenotypically mature T lymphocytes that comprised more than 50% of the cellular population. The T lymphocytes ranged from small cells with dark, round nuclei to slightly larger cells with elongated, irregular nuclei. There were occasional medium-sized blastic cells. There was also a variable infiltrate of histiocytes with or without epithelioid features, eosinophils and plasma cells, and increased vascularity. The peculiar morphologic features were also reproduced in other sites in the four patients for whom additional histologic materials were available for examination. We postulate that the abundance of T cells results either from a florid host reaction or from cytokine secretion by the neoplastic B cells, attracting T cells to the vicinity. The morphologic and immunologic features mimic those of a variety of benign lymphoproliferative diseases, angioimmunoblastic lymphadenopathy and lymphomas arising in angioimmunoblastic lymphadenopathy, peripheral T-cell lymphoma, secondary B-immunoblastic lymphoma, and Hodgkin's disease. Careful morphologic evaluation and immunophenotypic studies using leukocyte antibodies reactive in paraffin-embedded sections are of great assistance in determining a diagnosis.

Immunophenotypic analysis of sinonasal non-Hodgkin's lymphomas

A panel of paraffin effective antibodies recognizing B cells and T cells (LN-2, MB1, L26, MT1, UCHL1, kappa, lambda) was used to characterize the immunophenotypes of 26 sinonasal non-Hodgkin's lymphomas. Seventeen tumors were stage I, five were stage II, one was stage III, and three were stage IV. Nine lymphomas were classified morphologically as large cell, six were large cell immunoblastic, six were small cleaved cell, two were mixed small and large cell, two were small noncleaved cell, and one was lymphoblastic. None were follicular. Twenty-two lymphomas had a B cell immunophenotype, three were T cell neoplasms, and one was immunoreactive only for MT1. This predominance of sinonasal lymphomas with a B cell immunophenotype in patients residing in the United States contrasts with the almost exclusive occurrence of T cell sinonasal lymphomas in Chinese patients living in Hong Kong and Japanese patients residing in regions of Japan that are nonendemic for human T cell leukemia virus-1.

An unusual morphological variant of follicular lymphoma. Report of two cases

Most follicular lymphomas can be readily diagnosed on morphological grounds by finding closely packed pale-staining follicles partitioned by scanty dark-staining interfollicular tissue. We describe two cases of an unusual 'reverse' variant of follicular lymphoma in which the nodules have dark-staining centres and pale-staining cuffs due to concentration of centroblasts at the periphery of the neoplastic follicles. Recognition of this unusual pattern of follicular lymphoma is important, to avoid confusion with progressive transformation of germinal centres or nodular lymphocyte predominance Hodgkin's disease.

A simple guide to the terminology and application of leucocyte monoclonal antibodies

This review aims to provide a simple guide and quick reference to the terminology and diagnostic applications of leucocyte monoclonal antibodies. The differentiation cluster terminology, where applicable, is used throughout.

Monoclonal antibodies reactive with normal and neoplastic T cells in paraffin sections

Without fresh or frozen tissue, it previously has been impossible to confirm the T-cell nature of reactive or neoplastic lymphoid cells. The availability of antibodies reactive with T cells in paraffin sections now allows retrospective analysis of a large number of cases. Two commercially available monoclonal antibodies, MT1 and MT2, were tested for their reactivities with T cells in a wide range of formalin-fixed, paraffin-embedded tissues, including 130 cases of immunologically characterized lymphoma. In reactive lymph nodes, MT1 stained the T-cell areas, whereas MT2 stained both the T-cell areas and mantle-zone B lymphocytes. MT1 stained 38 of 55 T-cell lymphomas (69.1%; 94.7% of cases from one hospital that used a shorter fixation time, and 55.6% of cases from another hospital that used a longer fixation time). MT2 stained only 6 (10.9%) of the T-cell lymphomas. Among the 74 cases of B-cell lymphoma, 3 (4.0%) were stained by MT1 and 30 (40.5%) by MT2.MT1 was also reactive with 3 of 4 cases of granulocytic sarcoma, as expected from its reactivity with normal granulocytes. Neither MT1 nor MT2 stained Reed-Sternberg cells or their variants in HodgKin's disease. We conclude that MT1 is a valuable marker for T cells, particularly when used with a panel of antibodies reactive with B cells in paraffin sections. MT2 is of limited value because of its cross-reactivity with many B-cell lymphomas.

Critical assessment of four monoclonal antibodies reactive with B-cells in formalin-fixed paraffin-embedded tissues

Four commercially available monoclonal antibodies, MB1, MB2, LN1 and LN2, were studied to determine their sensitivity and specificity for the diagnosis of B-cell lymphomas when used on formalin-fixed paraffin-embedded tissues. In addition to 125 cases of immunologically characterized non-Hodgkin's lymphoma, a range of normal tissues, reactive lymphoid proliferations, Hodgkin's disease and granulocytic sarcomas were also studied. MB1 was found to give positive results in 53.6% of B-cell lymphomas, but the staining was sometimes weak and patchy; there was also cross-reaction with 1.8% of T-cell lymphomas. MB2 reacted with 88.4% of B-cell lymphomas and the reaction was often strong and diffuse, but it showed cross-reaction with 18.2% of T-cell lymphomas. LN1 and LN2 gave positive staining of 44.9 and 46.4% of B-cell lymphomas respectively, and the results appeared to be inferior to that obtained in B5-fixed tissues; staining was sometimes weak and focal, and they also gave false-positive results in a few cases of T-cell lymphoma. This study shows that MB1, LN1 and LN2 are fairly but not entirely specific for B-cells in the non-Hodgkin's lymphomas, but are not very sensitive when applied to formalin-fixed tissues. MB2 shows a high sensitivity but only moderate specificity. Therefore, when these antibodies are used to determine the immunophenotype of malignant lymphomas, the B-cell nature can be predicted with great confidence only when two, preferably three or more, of the antibodies give positive results. The potential applications of these antibodies are discussed.