Pediatric Lymphoid and Histiocytic Lesions in the Head and Neck

Lymphoid and histiocytic lesions of the head and neck in pediatric patients is a fascinating topic as most of these lesions are benign, but that the neoplastic cases are essential to diagnose accurately for appropriate treatment. It is thought that 90% of children will have palpable lymph nodes between the ages of 4 to 8; most, but not all, are non-malignant and some resolve spontaneously without treatment. This paper will look at many of the benign and malignant lesions of both lymphocytic and histiocytic origin that present in the head and neck of children focusing on their diagnostic criteria. There is a very pertinent discussion of nonmalignant lymphoid proliferations, as infections and other reactive conditions dominate the pathology of pediatric lymphohistiocytic head and neck lesions. Discussion of those lymphomas which arise more frequently in the head and neck focuses on those seen in children and young adults such as classic Hodgkin lymphoma and Burkitt lymphoma, as well as new more controversial entities such as pediatric-type follicular lymphoma. Histiocytic lesions, both benign and malignant, are described and may be challenging to diagnose.

Rare primary CNS anaplastic large cell lymphoma in an immunocompetent adult: a clinical-pathologic case report and review case of the literature

OBJECTIVE AND IMPORTANCE

Isolated anaplastic large cell lymphoma (ALCL) presenting in the primary central nervous system is distinctly uncommon. The authors describe a case that clinically and radiographically simulated a primary glial neoplasm.

CLINICAL PRESENTATION

A 39-year-old immunocompetent male presented with seizures and a rapidly enlarging right occipital/parietal lesion. Magnetic resonance images demonstrated a right occipitoparietal lesion, hypodense on T1WI, with patchy contrast enhancement with gadolinium and significant white matter edema pattern on T2WI along with mass effect and midline shift.

INTERVENTION

The patient underwent a frameless stereotactic assisted needle biopsy. There appeared to be a clear demarcation between white matter and tumor with no obvious necrosis. Biopsy showed a proliferation of single cells and poorly cohesive groups of cells with large, pleomorphic nuclei, many containing prominent nucleoli, and a moderate amount of cytoplasm. Immunohistochemical staining revealed CD-30 and ALK-positivity typical of ALCL, a rare form of T-cell lymphoma. An extensive workup revealed neither systemic disease nor evidence of immunocompromise.

CONCLUSION

Reported in less than 20 patients, primary ALCL in an immunocompetent patient is rarely found intracranially; however, its ability to mimic glial neoplasms as well as other pathologies underlines its importance.

c-Kit (CD117) reactivity in extramedullary myeloid tumor/granulocytic sarcoma

CONTEXT

c-kit, a proto-oncogene, encodes the transmembrane tyrosine kinase receptor CD117 and is detected by flow cytometry in the majority of cases of acute myeloid leukemia. The prognostic significance of the presence of c-Kit in acute myeloid leukemia is debated. Recently, c-kit inhibitors have been studied as possible therapies against hematopoietic malignancies; therefore, c-Kit detection may have important implications for treatment.

OBJECTIVES

In this study, we investigated the expression of c-Kit in granulocytic sarcoma (GS) using paraffin-embedded tissue.

DESIGN

Routinely formalin-fixed, paraffin-embedded tissues from 30 cases of GS were studied using immunohistochemistry. c-Kit (C-19) (a polyclonal antibody against carboxy terminal domain of c-Kit p145 or CD117) reactivity was compared with myeloperoxidase and lysozyme. The immunohistochemical panel also included CD34, CD68, CD43, Bcl-2, CD45RB, CD20, CD3, CD10, terminal deoxynucleotidyl transferase (TdT), and CD79a.

RESULTS

The morphologic patterns included well-differentiated (5 cases), poorly differentiated (19 cases), and blastic forms (6 cases). Clinical data were obtained from 28 of 30 patients. Granulocytic sarcoma presented in lymph nodes in 10 cases, whereas in 20 cases it presented in extranodal sites. c-Kit reactivity was found in 87% (26/30) of the GS cases. There was no significant difference in c-Kit positivity between the nodal (90%, 9/10) and extranodal (85%, 17/20) neoplasms. c-Kit expression was not associated with the degree of the myeloid maturation. Two of 13 lymphoblastic lymphoma control cases and 1 of 28 of the large B-cell lymphomas were weakly immunoreactive with c-Kit.

CONCLUSIONS

c-Kit reactivity can be demonstrated in a high percentage of GS cases; its presence may be useful not only in diagnosis, but also in the treatment of GS with new modalities.

Cutaneous follicle center lymphoma: a clinicopathologic study of 19 cases

Cutaneous follicle center lymphoma (FCL) is reported to have a unique immunophenotype and clinical course as compared with nodal FCL. We studied 19 cases of FCL of the skin using paraffin embedded tissue. An immunohistochemistry panel included CD45, CD3, CD20, CD43, CD21, bcl-2, bcl-6, CD5, and CD10. Molecular studies were performed by polymerase chain reaction for immunoglobulin heavy chain (IgH) and t(14;18). Trisomy 3 was performed by fluorescent in situ hybridization (FISH) in 13 cases. Follow up was obtained in 17 cases (range 3 to 137 months). Patients included 10 females and 9 males ranging in age from 33 to 88 years at first presentation (mean, 64). Twelve of 19 presented in the head and neck and 6 in the trunk and 1 on the arm. All had no known lymph node disease at presentation. Seventeen patients had no nodal disease with a minimum 3 month follow-up; 2/19 had unknown lymph node status with no follow-up. All cases were immunoreactive with CD20 and negative with CD3. Bcl-2 was immunoreactive in 11/18 cases, bcl-6 in 15/15, CD10 in 14/17, CD43 in 2/16 (both were CD10 immunoreactive) and CD5 in 1/15 (it was also bcl-6 immunoreactive). Eight of 18 cases were monoclonal for IgH. Three of 17 showed the presence of t(14;18). FISH was positive in 4 cases for trisomy 3 ranging from 16 to 22% (12% threshold). Follow-up showed no evidence of disease in 14/17 patients (4 to 137 mos). 3/17 patients are alive with disease (17 to 100 mo), and no patients died of disease.

Low-grade B-cell lymphoma with coexpression of both CD5 and CD10. A report of 3 cases

The coexpression of CD5 and CD10 has previously been reported in cases of intermediate- and high-grade lymphomas and in precursor B cells in normal or regenerating bone marrow. We report 3 cases of low-grade B-cell lymphoma that were found to coexpress CD5 and CD10 at the time of initial diagnosis. The first case was classified as small lymphocytic lymphoma; the second as follicle center lymphoma, follicular grade 1; and the third as small B-cell lymphoma otherwise not specified. Currently, the clinical implication of the coexpression of CD5 and CD10 is not known. We describe this finding to highlight the difficulty that may be encountered in classifying lymphomas in cases where this coexpression is present.

Splenic inflammatory myofibroblastic tumor (inflammatory pseudotumor): a clinicopathologic and immunophenotypic study of 12 cases

CONTEXT

Inflammatory pseudotumor is an uncommon and enigmatic lesion. The spindle cells found in this tumor have features of myofibroblasts. Because of the indefinite relationship of these lesions with inflammatory fibrosarcoma and their indefinite biologic behavior, inflammatory pseudotumor is currently classified as inflammatory myofibroblastic tumor (IMT). To date, only case reports or small series have been published on these tumors, which are primary in the spleen.

DESIGN

In this study, we describe the clinical, morphologic, and immunophenotypic findings of 12 cases of splenic IMT and examine their relationship to Epstein-Barr virus (EBV).

RESULTS

The patients included 8 women and 3 men, ranging from 19 to 77 years of age (mean, 53 years; median, 60 years). Demographic data were unavailable for 1 patient. Patients generally presented with abdominal pain (n = 5) and fever (n = 4). Associated lesions included renal cell carcinoma (n = 2), colonic adenocarcinoma (n = 1), and cholecystitis (n = 1). All tumors were composed of a bland spindle cell proliferation in association with a variable mixed inflammatory component. There were 2 growth patterns, namely, a cellular spindle cell pattern and a hypocellular fibrous pattern. An immunohistochemical panel confirmed the myofibroblastic nature of the spindle cells. The spindle cells of 2 cases were immunoreactive for EBV latent membrane protein 1, whereas 6 of 10 cases were positive for EBV-encoded RNA using in situ hybridization. Follow-up was available for 8 patients; 6 were alive with no evidence of recurrence and 2 were dead of other causes.

CONCLUSION

Splenic IMTs are uncommon lesions that can be distinguished from other conditions using a combination of clinical, histologic, and immunophenotypic findings. Epstein-Barr virus may play a role in the pathogenesis of splenic IMT, and there may be an association of splenic IMT with concomitant disease or malignancy. Most splenic IMTs have an excellent long-term prognosis.

Quantitative real-time reverse transcription-PCR assay for cyclin D1 expression: utility in the diagnosis of mantle cell lymphoma

BACKGROUND

The t(11;14)(q13;q32) translocation present in the majority of mantle cell lymphomas (MCLs) places the cyclin D1 gene under the control of immunoglobulin transcriptional regulatory elements, causing overexpression of cyclin D1. Quantification of cyclin D1 expression can distinguish MCL from other lymphomas.

METHODS

A quantitative real-time reverse transcription (RT)-PCR assay was developed for cyclin D1 mRNA suitable for use with RNA extracted from fresh and formalin-fixed, paraffin-embedded tissues. Specimens were amplified in an Applied Biosystems Model 7700 Sequence Detection System in reactions containing primers and probes for cyclin D1 and a control gene, beta(2)-microglobulin. Relative expression of the two genes was standardized against a control MCL cell line, M02058.

RESULTS

The range of cyclin D1 expression among 20 MCLs was substantially higher than that in other lymphomas and reactive lymph nodes. By choosing an optimal cutoff point for assessing overexpression, the sensitivity and specificity of the assay for the diagnosis of MCL in lymph node specimens both approached 100%: Overexpression was detected in 20 of 20 MCLs, but in none of 21 non-mantle-cell lymphomas or 10 reactive lymph nodes.

CONCLUSIONS

Quantitative real-time RT-PCR for cyclin D1 overexpression provides a rapid diagnostic test with clinical utility in the diagnosis of MCL.

T-cell lymphoma presenting in the breast: a histologic, immunophenotypic and molecular genetic study of four cases

Primary non-Hodgkin's lymphoma of the breast is uncommon. Most primary breast lymphomas are of B-cell phenotype, with only rare cases showing a T-cell phenotype. In this study, we report the clinicopathologic features of four cases of T-cell lymphoma in the breast. The patients all were female with a mean age of 48 years (range, 13 to 77 years). All cases showed immunoreactivity in paraffin-embedded tissue for T-cell markers CD3, CD45RO, and CD43. beta F1 was positive in three of four cases. The four cases were further subclassified as anaplastic large cell lymphoma (CD30 positive) of T-immunophenotype; natural killer/T-cell lymphoma; peripheral T-cell (CD4 positive), large cell type; and peripheral T-cell (CD8 positive, T-cell intracellular antigen positive), medium cell type. Three of the four cases were monoclonal for T-cell receptor beta and/or T-cell receptor gamma. The one case of natural killer/T-cell lymphoma was negative for monoclonality with both T-cell receptor beta and gamma by molecular diagnostic studies. In all cases, IgH was negative. Follow-up was obtained in three cases. Two patients died within less than 1 year after the diagnosis. The third patient died within 18 months of the diagnosis. Our results suggest an aggressive clinical course for T-cell lymphomas that present in the breast.

Immunoperoxidase detection of CD10 in Precursor T-lymphoblastic lymphoma/leukemia: a clinicopathologic study of 24 cases

CONTEXT

CD10 was originally reported in non-T-cell lymphoblastic lymphomas/leukemias. It has since been identified, however, in a minority of cases of T-lympho-blastic lymphoma/leukemia and other hematopoietic and nonhematopoietic entities. The usual method for the detection of CD10 previously required fresh tissue. A new antibody for CD10 (56C6) in paraffin embedded tissue sections, however, has recently become available.

OBJECTIVE

To study the expression of CD10 in paraffin sections of T-lymphoblastic lymphoma/leukemia using monoclonal antibody 56C6.

DESIGN

Twenty-four cases of T-lymphoblastic lymphoma/leukemia in various anatomic sites were studied. Immunohistochemical analysis with CD10 and a panel of other hematolymphoid antibodies was performed in all 24 cases. Gene rearrangement studies for the T-cell receptor by the polymerase chain reaction were performed in 18 of 24 cases.

RESULTS

All cases were positive with at least 2 T-cell markers. In 15 (63%) of 24 cases CD10 was positive. T-cell receptor gene rearrangement was detected in 10 of 18 cases.

CONCLUSIONS

Immunodetection of CD10 in T-lympho-blastic lymphoma/leukemia using monoclonal antibody 56C6 is common. This finding is useful in the evaluation of T-cell neoplasms.

Antiapoptotic marker Bcl-X(L), expression on Reed-Sternberg cells of Hodgkin's disease using a novel monoclonal marker, YTH-2H12

Inhibitors of apoptosis may regulate tissue differentiation and promote cell survival in neoplasia. A new apoptosis inhibitor of the bcl-2 gene family, bcl-X(L), was recently found in some types human neoplasia but not in normal tissue. We investigated bcl-X(L) expression in 419 cases of normal and neoplastic lymphoid lesions using immunohistochemistry with the monoclonal antibody bcl-X(L) (YTH-2H12). Ninety-four percent (141/150) of classic Hodgkin's disease (HD) were positive for bcl-X(L) with strong intensity in most Reed-Sternberg (RS) cells. Forty-eight percent (38/80) of nodular lymphocyte predominance (LPHD) were positive. In the non-Hodgkin's lymphomas (NHL), bcl-X(L) was expressed in a low percentage of cases (< 20%), with the exception of follicle center lymphoma, grade III/III (78%). All reactive hyperplastic lesions were negative for bcl-X(L). RS cells, which expressed bcl-X(L), were not labeled by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). We found RS cells expressing bcl-X(L) were absent of DNA fragmentation (apoptosis). Our data provide evidence that bcl-X(L) is abnormally expressed in the RS cells of HD and some types of NHL raising speculation that inhibition of apoptosis may be important in the pathogenesis of lymphoma, specifically HD. In addition, the previously reported correlation between bcl-X(L) and Epstein-Barr virus expression in HD was not supported by this study.

Enhanced sensitivity with a novel TCRgamma PCR assay for clonality studies in 569 formalin-fixed, paraffin-embedded (FFPE) cases

BACKGROUND

Clonal rearrangement of genes encoding the immunoglobulins (Ig) and T-cell antigen receptors (TCR) are considered to be useful markers for the diagnosis of lymphoma and for determining the clonal origins of B- and T-cell populations in lymphoid neoplasms.

METHODS AND RESULTS

Polymerase chain reaction-based clonality assays for TCRgamma, TCRbeta, and immunoglobulin (Ig) heavy chain (IgH) gene rearrangements were evaluated for diagnostic sensitivity and specificity in 569 formalin-fixed, paraffin-embedded (FFPE) tissues. Combined TCRbeta and TCRgamma assays enhanced the routine detection of TCR clonality to 90% of all peripheral T-cell lymphoma (PTCL) cases. IgH clonality was detected in 59% of 241 peripheral B-cell lymphoma (BCL) cases and 6% of 169 PTCL cases. Of 452 lymphomas, 5% could not be classified phenotypically as B or T lineage after immunohistochemical and clonality studies. Of all BCL cases analyzed, 24% had detectable TCRbeta and/or TCRgamma clonality. Of these BCL with biclonal results, 47% were extranodal lymphomas from skin and various tissues.

CONCLUSIONS

Clonality assays were useful for distinguishing reactive or benign lymph nodes from neoplastic lymphoid infiltrates in most cases. The inclusion of TCRb and TCRg assays in the assessment of lymphomas results in a significant increase in the sensitivity of clonality detection, but is of limited utility in assessing the T- or B-cell phenotype of the tumor.

Differential expression of cyclin D1 in mantle cell lymphoma and other non-Hodgkin's lymphomas

Mantle-cell lymphomas are associated with a characteristic chromosomal translocation, t(11;14)(q13;q32). This translocation involves rearrangement of the bcl-1 proto-oncogene from chromosome 11 to the immunoglobulin heavy chain gene on chromosome 14, resulting in an overexpression of cyclin D1 mRNA (also known as bcl-1 and PRAD1). In the current study performed on paraffin-embedded tissue, cyclin D1 mRNA could be detected in 23 of 24 mantle-cell lymphomas by reverse transcription polymerase chain reaction (RT-PCR) whereas only 9 of 24 demonstrated a t(11;14) by PCR. However, we also found that cyclin D1 mRNA could be detected in the majority (11 of 17, 65%) of non-mantle-cell lymphomas and in a minority of atypical lymphoid hyperplasias (3 of 7, 43%). Cyclin D1 mRNA expression was not observed in floridly reactive lymph nodes (0 of 9) or in unstimulated lymph nodes (0 of 20), suggesting that it is a sensitive adjunct marker for malignant lymphoproliferative processes, but not specific for mantle-cell lymphoma. A semiquantitative RT-PCR assay was developed that compared the ratio of cyclin D1 to the constitutively expressed gene beta2-microglobulin. Using this assay on a limited number of our specimens, cyclin D1 overexpression in mantle-cell lymphoma could be reliably distinguished from its expression in other non-Hodgkin's lymphomas. This assay for cyclin D1 expression, designed for formalin-fixed, paraffin-embedded tissue, was a very sensitive and specific marker for mantle-cell lymphoma.

Expression of CD44 (HCAM) in small lymphocytic and mantle cell lymphoma

Small lymphocytic lymphoma (SLL) and mantle cell lymphoma (MCL) are small B-cell lymphomas that share many morphological and immunophenotypic features, both expressing the T-cell antigen CD5. Because of this, there is speculation that these two lymphomas may have a common origin, both arising from the mantle zone of the lymph node. CD44 (HCAM), a glycoprotein "homing receptor," has been reported as a marker of small B-cell lymphomas for determining behavior as well as the nodal cell of origin. Intensity of CD44 expression also has been correlated with dissemination of lymphoma. We studied 50 cases with classic features of SLL (30 cases) or MCL (20 cases). Immunophenotypic analysis was performed on paraffin sections. All cases of MCL and SLL were CD20 positive; CD5 was expressed in 19 of 25 (76%) SLL and 11 of 15 (73%) MCL. Cyclin D1 was expressed in 11 of 17 (76%) MCL and no cases of SLL. CD43 coexpression was seen in 27 of 29 (93%) SLL and 17 of 19 (89%) MCL. CD23 was positive in 25 of 28 (89%) SLL and 2 of 20 (10%) MCL. Bcl-2 was positive in 18 of 22 (82%) SLL and 15 of 16 (94%) MCL. CD44 was positive with moderate to strong intensity in 11 of 30 SLL and 15 of 20 MCL. Peripheral blood involvement did not correlate with CD44 immunoreactivity. MCL tended to have intense CD44 immunoreactivity, whereas SLL tended to show weaker CD44 intensity. This trend in the intensity of CD44 in MCL suggests that CD44 may be helpful in distinguishing SLL from MCL and possibly elucidating the origin of these CD5-positive B-cell neoplasms.

The blastic variant of mantle cell lymphoma arising in Waldeyer's tonsillar ring

We present three cases of blastic mantle cell lymphoma with an unusual initial manifestation in Waldeyer's ring with methods for differentiating it from other blastic neoplasms of the head and neck. All cases presented with a feeling of fullness in the area of the mass. Morphologically, the tumours were blastic with a high mitotic rate (three to nine per high power field). All were B-cell phenotype with coexpression of CD43. In all cases cyclin D1 and bcl-2 were positive and CD23 negative. Blastic mantle cell lymphoma occurring in Waldeyer's tonsillar ring may be mistaken for other high grade haematopoietic neoplasms. Immunohistochemistry and awareness of this type of lymphoma are helpful in differentiating it from other neoplasms.

Primary non-Hodgkin's splenic lymphoma

OBJECTIVES

To describe the imaging, clinical and pathological features of primary splenic lymphoma using a strict definition.

METHODS

Of 21 cases, plain films were available in nine, sonograms in 10 and CT in 16. We categorized the spleen as either normal, enlarged with no focal defects (type 1), studded with miliary masses (type 2), containing multifocal masses of varying size (1-10 cm) (type 3) or containing a solitary large mass >5 cm without (type 4A) or with (type 4B) central hypodensity/anechoic areas.

RESULTS

Clinical presentations were left upper quadrant pain, weight loss and/or fever. One case was found incidentally on CT. Fourteen were type 4A, three type 4B, four type 3 and none were type 1 or 2. Nine of 10 cases were hypoechoic. In 11/12 cases with enhanced scans, the lesions are hypodense relative to the splenic parenchyma, and in one case, the lesion was necrotic. Rim enhancement was seen in one case.

CONCLUSION

Primary splenic lymphoma usually presents as a mass or masses rather than with splenomegaly alone. Splenectomy may be required for diagnosis.

Waldenström's macroglobulinemia: a clinicopathologic study of 22 cases

BACKGROUND

Waldenström's macroglobulinemia (WM) is a rare immunoproliferative disorder, the clinical course of which varies. In related B-cell neoplasms, such as multiple myeloma and chronic lymphocytic leukemia, the histologic features of bone marrow are considered to be of prognostic relevance.

METHODS

To assess the prognostic features of WM, the authors reviewed the clinical and pathologic features of 22 patients. Bone marrow aspirates and core biopsies were available for each case. Immunostains for a panel of hematopoietic markers as well as p53 and proliferating cell nuclear antigen (PCNA) were performed.

RESULTS

There were 14 males and 8 females, with a mean age of 60 years. At presentation, two histologic subtypes, lymphoplasmacytoid (73%) and lymphoplasmacytic (27%), were observed. Four patterns of bone marrow infiltration were delineated: diffuse (45%), nodular-interstitial (22%), mixed paratrabecular-nodular (20%), and paratrabecular (13%). In 11 patients, the infiltrate occupied greater than 70% of the bone marrow; in 8 patients, 30-70%; and in 3 patients, less than 30%. PCNA reactivity was observed in 58% of cases and p53 reactivity in 21%. Ten patients died of disease with an average survival of 84 months. The remaining 12 patients were alive with disease at last follow-up. The pretreatment parameters that were correlated with shorter survival were hemoglobin, white blood cell count, platelet count, splenomegaly, lymphadenopathy, and serum immunoglobulin M level.

CONCLUSIONS

The findings of this study suggest that some pretreatment parameters, such as cytopenia, serum immunoglobulin M level, splenomegaly, and lymphadenopathy, correlate with poor prognosis for patients with WM. In contrast, histologic features and expression of p53 and PCNA did not correlate significantly with survival.

Histologically discordant lymphomas with B-cell and T-cell components

We describe the clinical, histologic, immunophenotypic, and genotypic features of five cases of histologically discordant lymphomas with B-cell and T-cell components. Three patients presented with B-cell lymphoma; T-cell lymphoma subsequently developed. One patient presented with T-cell lymphoma; B-cell lymphoma subsequently developed. One patient presented with synchronous B-cell and T-cell lymphomas. There were three men and two women. The median age at the initial diagnosis of lymphoma was 66 years. The mean interval between the development of the two lymphomas was 83 months. All patients died of disease. The mean survival was 96 months after the initial diagnosis of lymphoma and 14 months after the diagnosis of the histologically discordant lymphoma. Epstein-Barr virus was found in two cases--the B-cell lymphoma in the patient who presented with synchronous lymphomas, and the subsequent T-cell lymphoma in one of the patients who presented with B-cell lymphoma. Based on the results of immunophenotypic and genotypic analyses, these cases likely represent the occurrence of two distinct lymphoid neoplasms rather than histologic progression of the same neoplastic clone. Furthermore, a subset of these cases are Epstein-Barr virus-associated.

Childhood Hodgkin's disease in the United States: an analysis of histologic subtypes and association with Epstein-Barr virus

Hodgkin's disease (HD) typically has a bimodal age distribution and is less common than non-Hodgkin's lymphoma in the pediatric age group, especially in very young children. Recent reports described a high prevalence of Epstein-Barr virus (EBV) in HD from developing countries in both adult and pediatric populations. In this series, we studied with immunohistochemical analysis 44 cases of pediatric HD from the United States to investigate the association with EBV in developed countries and to determine which subtypes occur in this group. The 44 cases (40 boys, 4 girls; male-to-female ratio, 10:1) were categorized as nodular lymphocyte predominance in 16 (36.4%) of 44; nodular sclerosis in 13 (29.5%); and mixed cellularity in 4 (9.1%). Eleven of the cases were difficult to subclassify by the usual morphologic and immunophenotypic criteria. Of these, eight (18.1%) were designated interfollicular HD, and three were classified as HD "not otherwise specified." EBV LMP was positive in 38.6% of cases: 5 (38.5%) of the 13 with nodular sclerosis; 3 (75%) of the 4 with mixed cellularity; 1 (6.0%) of the 16 with nodular lymphocyte predominance; 7 (87.5%) of the 8 with interfollicular HD; and 1 (33.3%) of the 3 with HD "not otherwise specified." There was a strong association between the age of the patient and EBV expression. In children 4 years or younger, all of the 3 cases were LMP positive; in the 5- to 9-year-old age group, 8 (61.5%) of 13 were LMP positive; and in the 10- to 15-year-old group, only 21.4% were positive. Our results confirm the male predominance in pediatric HD and show an association with EBV, especially in the youngest patients and with the mixed cellularity and interfollicular subtypes. Most, but not all, cases of pediatric HD can be subclassified by traditional criteria.

Non-Hodgkin lymphoma of the stomach: a cause of linitis plastica

PURPOSE

To demonstrate the radiologic appearance of linitis plastica in non-Hodgkin lymphoma of the stomach and to correlate radiologic and pathologic findings.

MATERIALS AND METHODS

Of 34 cases of non-Hodgkin lymphoma of the stomach in the radiologic archives of the Armed Forces Institute of Pathology, nine had a linitis plastica appearance at barium study. The radiologic, endoscopic, and pathologic findings of these cases were reviewed.

RESULTS

All nine patients (six with primary gastric lymphoma, three with generalized lymphoma with stomach involvement) were symptomatic. Images from barium studies revealed a linitis plastica appearance with narrowing of the gastric antrum and/or body (n = 5), narrowing of the body and/or fundus (n = 3), and diffuse gastric narrowing (n = 1). On CT scans (n = 7), marked circumferential soft-tissue thickening (average thickness, 2.9 cm) of the gastric wall was seen. Patients were treated with subtotal gastrectomy and gastrojejunostomy (n = 5) or total gastrectomy and esophagojejunostomy (n = 4). In all cases, histopathologic specimens revealed a thickened gastric wall with lymphomatous cell infiltration. Wall thickening was associated with areas of fibrosis in only one case.

CONCLUSION

Non-Hodgkin gastric lymphoma should be recognized as another cause of linitis plastica, especially in patients with a history of lymphoma or evidence of generalized lymphoma at presentation.

Hodgkin's disease and an extranodal marginal zone B-cell lymphoma in the small intestine: an unusual composite lymphoma

We describe a 74-year-old man who presented with multifocal small bowel lesions, a large mesenteric mass, and enlarged mesenteric lymph nodes. In each of the extranodal sites and in two of three regional lymph nodes, there were classic histologic features of marginal zone B-cell lymphoma with adjacent areas of Hodgkin's disease, mixed cellularity subtype. Immunophenotypic analysis in the areas of low-grade B-cell lymphoma of mucosa-associated lymphoid tissue showed immunoreactivity for CD45RB and CD20 in the malignant small cell population. Conversely, the areas of Hodgkin's disease demonstrated positive immunoreactivity for CD15 and CD30 in the Reed-Sternberg cells and variants. Latent membrane protein for Epstein-Barr virus was also positive in the Reed-Sternberg cells and variants.

Extramedullary plasmacytoma of the head and neck: use of paraffin sections to assess clonality with in situ hybridization, growth fraction, and the presence of Epstein-Barr virus

The diagnosis of extramedullary plasmacytomas (EMP) is usually easy to conform with immunohistochemical stains for kappa and lambda. In some cases, however, immunostains are problematic. In addition, prognostic features are not well described nor is it known whether EMP are associated with the Epstein-Barr virus. Therefore, 23 EMP of the head and neck (from 20 patients) were studied to (1) compare a non-isotopic paraffin section in situ hybridization technique for kappa and lambda mRNA with standard immunohistochemical techniques for assessing light chain expression, (2) compare the histologic grade to the proliferative fraction using an antibody for the proliferating cell nuclear antigen, and (3) determine the frequency of Epstein-Barr virus (EBV) association using probes for the EBV DNA (EBV NOT 1) and RNA (EBER-1). Light chain class restriction was demonstrated in 22/23 biopsies by in situ hybridization and in 21/23 biopsies by standard immunohistochemical techniques. Five of the six biopsies of well-differentiated EMP had proliferating cell nuclear antigen scores of 0 to 10% positive cells and one had 11 to 25% positive cells compared with greater than 75% in the one poorly differentiated EMP. Of 15 moderately differentiated EMP, 10 had proliferating cell nuclear antigen scores of 11 to 75%, and 5 had scores of greater than 75%. EBV DNA was detected in 1/23 biopsies and EBV RNA in 4/23 biopsies (3 patients). Thus, non-isotopic in situ hybridization is a useful technique to document clonality of plasma cells in routinely fixed, paraffin-embedded sections. Unlike routine immunohistochemistry, in situ hybridization avoids the problem of detecting stromal or nonspecific uptake of immunoglobulin.(ABSTRACT TRUNCATED AT 250 WORDS)