Pediatric extranodal marginal zone B-cell lymphoma presenting as amyloidosis in minor salivary glands: a case report and review of the literature.

We report an unusual case of an extranodal marginal zone B-cell lymphoma (EMZL) arising in the labial minor salivary gland in an immunocompetent 11-year-old boy. The initial histopathologic review favored localized amyloidosis. However, further evaluation supported the diagnosis of low-grade B-cell lymphoma with plasmacytic differentiation, surrounded by deposits of AL κ-type amyloid. Clinical management consisted of excision with no recurrence at 1-year follow-up. This case demonstrates that a diagnosis of lymphoma must be considered in cases of amyloidosis associated with minor salivary gland involvement, even in children. In addition, we provide a literature review of extranodal marginal zone B-cell lymphoma arising in salivary glands.

Clusterin expression in cutaneous CD30-positive lymphoproliferative disorders and their histologic simulants.

BACKGROUND: Clusterin is a ubiquitous 80 kDa heterodimeric glycoprotein previously shown to be expressed on tumor cells of systemic and, to a lesser extent, primary cutaneous anaplastic large cell lymphoma (PC-ALCL). Lymphomatoid papulosis (LyP), an important differential diagnosis of ALCL, has been studied for clusterin expression in only a small number of cases. The aim of this study was to compare clusterin immunostaining patterns in LyP and other cutaneous histologic simulants with those of PC-ALCL. METHODS: Formalin-fixed, paraffin-embedded sections of PC-ALCL (6), LyP (20), mycosis fungoides with large cell transformation (MF-LCT, 12), pityriasis lichenoides et varioliformis acuta (PLEVA, 12), arthropod bite reaction (ABR, 12) and lymphomatoid reactions (LR, 9) were immunostained for clusterin and evaluated for staining pattern and distribution. All diagnoses were made with clinicopathologic correlation. RESULTS: Characteristic dot-like Golgi staining was identified in 10/20 LyP (50%), 4/6 PC-ALCL (67%) and 9/12 MF-LCT (75%). Two of 12 PLEVA (17%), 1 of 12 ABR (8%) and 2 of 8 LR (25%) had lymphocytes (< 25%) with diffuse cytoplasmic staining. Dermal dendritic cells stained strongly for clusterin. High background staining occurred in some cases. CONCLUSION: Clusterin immunostaining does not reliably distinguish between LyP, PC-ALCL or MF-LCT, but could distinguish LyP from its reactive histologic simulants.

ALK-positive anaplastic large cell lymphoma with primary bone involvement in children.

We describe the clinical, radiologic, and pathologic features of primary bone anaplastic large cell lymphoma (ALCL) in 3 boys. Radiologic imaging showed lytic lesions involving sacrum, femur, or rib. Bone was the only site of disease in 2 cases; an associated partial lymph node was involved in case 3. Differential diagnoses included osteomyelitis and small round cell tumors of childhood, particularly Ewing sarcoma. Preoperatively, ALCL was not a diagnostic consideration in any case. Two cases showed classic large pleomorphic cells; 1 showed a composite pattern with a distinct small cell component and the more typical large cell type. Neoplastic cells in all cases showed strong CD30 and anaplastic lymphoma kinase expression with relatively weak epithelial membrane antigen positivity. Cytotoxic granule protein was expressed in 2 cases. All cases showed unusually strong expression of neuron-specific enolase (NSE). Two patients were disease-free at last follow-up (15 months and 11 years); 1 patient died of disseminated disease within a year of diagnosis. ALCL should be considered a diagnostic possibility when evaluating neoplastic bone lesions in children. Although expression of NSE in ALCL has not been emphasized in the literature, it is worth noting because it may pose a diagnostic pitfall.

Lymphoid tissues from patients with infectious mononucleosis lack monoclonal B and T cells.

In typical cases of infectious mononucleosis (IM), lymphoid tissue is rarely submitted for pathological examination. When lymphoid tissues from IM cases are examined, the histological appearance of IM may be difficult to distinguish from malignant lymphoma. The purpose of this study was to address the utility of clinical molecular assays for T and B cell clonality in distinguishing IM from lymphoid malignancy. DNA was recovered from paraffin-embedded archival lymphoid tissues of 18 cases of IM and 13 control cases representing other reactive lymphoid hyperplasias. T cell receptor gamma (TCR-gamma) and immunoglobulin heavy chain (IgH) gene rearrangements were assayed using our standard clinical polymerase chain reaction procedures targeting each of the four functional variable (V) families and the three joining (J) families of the TCR-gamma gene, and framework III of the IgH gene, respectively. In 17 of 18 cases of IM, no monoclonal T or B cell populations were detectable. One case, the only spleen specimen in the study, had an oligoclonal pattern of TCR-gamma rearrangements. The control cases representing other reactive hyperplasias also lacked monoclonality. The assays used were sensitive to clonal populations as small as 5% of cells. In this case series, no monoclonal lymphoid populations were identified in any case of IM. This finding suggests that molecular studies are useful in distinguishing IM from lymphoid neoplasms.

Composite germ cell tumor and B-cell non-Hodgkin's lymphoma arising in the sella turcica.

We report the case of a composite malignant neoplasm consisting of germ cell tumor and B-cell non-Hodgkin's lymphoma occurring in the sella turcica of a young girl who presented with hypopituitarism. Routine hematoxylin and eosin-stained sections of a resected suprasellar tumor demonstrated a neoplasm composed of 2 distinct morphologies. A panel of immunohistochemical markers was used to confirm the morphologic impression of germinoma (cytokeratin AE1/AE3-CAM 5.2, cytokeratin 7, neuron-specific enolase, and focally placental alkaline phosphatase positive) and mature B-cell lymphoma (CD20 positive; pancytokeratin, placental alkaline phosphatase, and terminal deoxynucleotidyl transferase negative). To the best of our knowledge, this is the first reported case of such a composite tumor in the central nervous system.

Nodular lymphocyte predominant Hodgkin lymphoma. An immunophenotypic reappraisal based on a single-institution experience.

In our experience, certain commonly cited immunophenotypic features of nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) are not encountered in day-to-day practice. We reviewed 60 cases of NLPHL (18 women, 42 men; median age, 34 years) to discern immunophenotypic features from a large, single-institution cohort. All cases contained lymphocytic and histiocytic (L&H) cells. These cells expressed CD20 in 98% (59/60), CD79a (usually faint) in 87% (27/31), CD30 in 7% (4/59), epithelial membrane antigen in 21% (12/56), bcl-2 in 5% (2/41), and bcl-6 in 83% (30/36) of cases. CD10 was negative in all 36 cases studied; 100% of cases (55/55) demonstrated CD3+ rosettes. Although CD57+ T cells were common within the background infiltrate, CD57+ rosettes were seen in only 48% of cases (15/31) and were rare when encountered. Based on these patterns, we conclude that bcl-2 and bcl-6 may be useful additions to the immunophenotypic analysis of NLPHL, but that the diagnostic usefulness of epithelial membrane antigen and CD57 rosettes may have been overemphasized in previous reports.

Histopathologic features of splenic small B-cell lymphomas. A study of 42 cases with a definitive diagnosis by the World Health Organization classification.

We studied 42 cases of splenic small B-cell lymphoma (SBL) (21 women, 21 men; aged 32-82 years; median, 65 years) with a definitive diagnosis by the World Health Organization classification: chronic lymphocytic leukemia (CLL), 8; mantle cell lymphoma (MCL), 9; follicular lymphoma (FL), 12; marginal zone lymphoma, 13 (splenic [SMZL], 12; extranodal [EMZL], 1). Splenectomy was performed for diagnosis or therapy; splenic weights were 0.2 to 3.8 kg (median, 1.4 kg). In general, splenic SBLs showed white pulp (WP) expansion; morphologic features of the nodules recapitulated the corresponding lymph node histopathologic features. "Marginal zones" were observed commonly in SMZL and FL, may be present in MCL involving the spleen, and may be seen in hilar lymph nodes (HLNs) in SBLs other than SMZL. FL may simulate SMZL and can be distinguished by the presence of neoplastic follicles and HLN morphologic features. Extracellular hyaline deposits (EH) are common in FL and SMZL. MCL typically shows WP expansion by a monotonous small lymphocytic infiltrate, without diffuse red pulp (RP) infiltration or EH; leukemic MCL may show RP infiltration. Splenic morphologic features in CLL vary in WP or RP dominance; marginal zones usually are not observed in CLL.

Follicular hodgkin lymphoma: a histopathologic study.

Follicular Hodgkin lymphoma (FHL) is a form of classic Hodgkin lymphoma with morphologic similarity to nodular lymphocyte predominant Hodgkin lymphoma (NLPHL). We present the clinicopathologic features of 13 FHL cases and compare their morphologic features with 40 cases of NLPHL. Seven males and 6 females had FHL in the lymph nodes of the neck (6 patients), axilla (3 patients), groin (2 patients), and mediastinum (1 patient) and in the nasopharynx (1 patient). All FHLs had follicles with small, eccentric germinal centers (GCs) and expanded mantle zones containing classic Reed-Sternberg (RS) cells; reactive GCs also were seen in 6 of 13 cases. The RS cells were CD30+, fascin+ in 13 cases; CD15+ in 11 cases; CD20+ in 4 cases; CD79alpha+CD20- in 1 case; and negative for epithelial membrane antigen in 12 cases; they were surrounded by CD3epsilon+ and CD57+ rosettes in 13 and 2 cases, respectively. Morphologically, FHL may closely simulate NLPHL, and, thus, immunohistochemical analysis is essential to confirm the diagnosis. Clues helpful in diagnosing FHL include the presence offollicles with GCs, classic RS cells, and a relative absence of histiocytes.

Usefulness of anti-CD117 in the flow cytometric analysis of acute leukemia.

We assessed the diagnostic usefulness of adding anti-CD117 to our existing flow cytometric profile in the analysis of 150 consecutive cases of acute leukemia (de novo or relapsed acute myelogenous leukemia [AML], AML arising in myelodysplastic syndrome, blast crisis of chronic myelogenous leukemia [CML], acute lymphoblastic leukemia, acute unclassifiable leukemia, and biphenotypic leukemia). CD117 was expressed on more than 10% of blasts in 64% of de novo AMLs (42/66), 95% of relapsed AMLs (19/20), 75% of AMLs arising from a myelodysplastic syndrome (6/8), and 25% of myeloid blast crisis in CMLs (1/4). CD117 was not expressed in acute lymphoblastic, acute biphenotypic, or unclassified leukemia or lymphoid blast crisis of CML. The specificity, positive predictive value, sensitivity, and negative predictive value of CD117 for AML were 100%, 100%, 69%, and 62%, respectively. CD117 is a specific marker for myeloblastic leukemias. Sensitivity is greatest in French-American-British M2 and relapsed AML. Intensity of CD117 expression is dim. Despite the high specificity and positive predictive value, the addition of anti-CD117 to our panel did not prove essential for the assignment of blast lineage.

Expression and phosphorylation of eukaryotic translation initiation factor 4E binding protein 1 in B-cell lymphomas and reactive lymphoid tissues.

CONTEXT: Cap-mediated messenger RNA translation controlled by the eukaryotic initiation factor 4F (eIF-4F) complex plays a key role in human cancer. eIF-4F activity is controlled by a repressor binding protein (4E-BP1), which promotes translation when phosphorylated. OBJECTIVE: To examine the level of expression and phosphorylation of 4E-BP1 in various subtypes of B-cell lymphoma and reactive lymphoid tissues. DESIGN: Archival formalin-fixed, paraffin-embedded B-cell lymphoma samples and reactive lymphoid tissues were immunostained and examined for expression of 4E-BP1 and phosphorylated 4E-BP1. Expression of components of the eIF-4F complex and unphosphorylated and phosphorylated 4E-BP1 was confirmed using Western immunoblotting on lysates of frozen lymphoma samples and reactive tissues. RESULTS: Immunohistochemical analysis demonstrated weak to undetectable 4E-BP1 staining within benign, reactive germinal centers (N = 10). In contrast, 4E-BP1 was consistently expressed (moderate to strong staining) in 98% of various subtypes of mature B-cell lymphoma (N = 50). 4E-BP1 expression was also demonstrable in all 4 lymph nodes with in situ or partial involvement by follicular lymphoma and in all 12 cases of BCL2-negative lymphoma. The level of phosphorylation of 4E-BP1 in lymphomas, evaluated by immunohistochemistry, was heterogeneous. CONCLUSIONS: The immunohistochemical expression pattern of 4E-BP1 exhibits regional and cellular specificity in reactive lymphoid tissues and may offer a diagnostic tool for distinguishing reactive follicles from neoplastic B-cell proliferations.

Hodgkin lymphoma.

Hodgkin disease was first described more than 175 years ago. Clinically and histomorphologically, the features of Hodgkin lymphoma are unusual for a lymphoma or for other malignancies. The incidence of Hodgkin lymphoma is estimated to be 7400 new cases per year in the United States, resulting in an age-adjusted yearly rate of 2.7 per 100,000 per year. There have been numerous classifications of non-Hodgkin lymphoma over the years, but the organizational schemes of Hodgkin lymphoma have been stable. This article reviews the diagnosis of the various types of Hodgkin lymphoma classification, diagnosis and differential.

Site-specific morphologic differences in extranodal marginal zone B-cell lymphomas.

CONTEXT: Lymphoepithelial lesions (LELs) are a useful diagnostic feature of extranodal marginal zone B-cell lymphoma (EMZL); however, there is scant literature comparing their frequency and morphology at various sites. OBJECTIVE: To evaluate any diagnostically useful, site-specific, morphologic patterns in EMZLs. DESIGN: In this retrospective review, we evaluated 136 EMZLs from different sites for LEL pattern and other pathologic differences, including CD43 coexpression and plasma cell component features. RESULTS: Prominent and destructive LELs were most common in salivary and thyroid gland cases, and LELs were rare to absent in breast, skin, and ocular adnexa cases. An LEL pattern with lymphocytes "stuffing" glandular lumina was seen in lung, thyroid, and salivary gland cases. Monoclonal plasma cells were most common in breast, upper aerodigestive tract, skin, and salivary gland cases. CD43 coexpression was seen in 36% of cases, most commonly in salivary gland, stomach, and upper aerodigestive tract. CONCLUSIONS: The relative importance of LEL pattern, CD43 coexpression, and clonal plasma cell component in EMZLs is site-dependent, and the differences may aid in the diagnosis of EMZLs at different anatomic sites.

Highly aggressive ALK-positive anaplastic large cell lymphoma with a leukemic phase and multi-organ involvement: a report of three cases and a review of the literature.

Anaplastic large cell lymphoma (ALCL) is an aggressive neoplasm of T- or null cell phenotype and is recognized as a distinct clinicopathologic subtype of non-Hodgkin lymphoma (NHL) in the revised World Health Organization (WHO) classification of hematopoietic neoplasms. It is rarely associated with leukemic phase. Most cases with leukemic involvement are the small cell variant of ALCL. These cases often lack the pleomorphism seen in the common variant of ALCL and may be misdiagnosed. We report a series of three patients who presented with leukemic phase ALCL. The patients included an 11-year-old boy, a 29-year-old man, and a 59-year-old woman. The clinical and pathologic features of these cases are reviewed. The patients in our case series with leukemic phase ALCL exhibited rare clinical features. The patients presented with massive extranodal disease involving cerebrospinal fluid (CSF), liver, spleen, lungs, and bone marrow. CSF involvement was documented morphologically as well as by flow cytometry in two patients. Two of the patients had small cell variant and the third patient had common type ALCL. The neoplastic cells in all three patients were ALK positive; however these patients died within months of diagnosis. Leukemic phase ALCL is rare, and behaves in an aggressive manner. Some, but not all, cases in the literature presenting with peripheral blood involvement had small cell variant ALCL, as seen in two of our cases. The leukemic phase of ALCL should be considered when a T-cell leukemia with unusual morphologic features is encountered.

Fascin expression in diffuse large B-cell lymphoma, anaplastic large cell lymphoma, and classical Hodgkin lymphoma.

CONTEXT: Fascin is an actin-bundling protein involved in the formation of dendritic processes. Fascin is a sensitive marker for classical Reed-Sternberg cells and has a high negative predictive value for diagnosis of classical Hodgkin lymphoma (CHL). Fascin has been used to distinguish CHL from non-Hodgkin lymphoma. Recently, it was shown that fascin might not help differentiate CHL from anaplastic large cell lymphoma (ALCL). Moreover, fascin has not been extensively studied in the context of other large cell lymphomas. OBJECTIVE: To analyze fascin expression in diffuse large B-cell lymphoma (DLBCL) and also reexamine its usefulness in discriminating CHL from ALCL. DESIGN: Formalin-fixed, paraffin-embedded tissue samples from 41 cases of DLBCL, 30 cases of CHL, and 30 cases of ALCL were analyzed. Fascin expression was compared across each type of lymphoma with additional correlation between fascin positivity and ALK-1 expression in ALCL performed. RESULTS: Only 6 (14.6%) of 41 cases of DLBCL stained positively for fascin, with most neoplastic large cells exhibiting a weak staining pattern. Fifteen (50%) of 30 cases of ALCL showed positivity for fascin, with most large cells staining strongly. All 30 cases of CHL demonstrated intense positive staining. Sixty percent of fascin-positive ALCLs were positive for ALK-1, while 66.7% of fascin-negative ALCLs were positive for ALK-1. CONCLUSIONS: Fascin is highly sensitive for CHL and has a very high negative predictive value (100% in this series) for distinguishing CHL from DLBCL or ALCL. However, the specificity and positive predictive value for fascin are much higher in distinguishing CHL from DLBCL than in distinguishing CHL from ALCL. Expression of fascin appears more useful in the differential diagnosis of CHL versus DLBCL than in the differential diagnosis of CHL versus ALCL.

Lymphocytic mastitis and diabetic mastopathy: a molecular, immunophenotypic, and clinicopathologic evaluation of 11 cases.

Lymphocytic mastitis and diabetic mastopathy are uncommon fibroinflammatory breast diseases. The lesions seen in these entities are unique in that the associated lymphoid infiltrates are composed of predominantly B cells. In addition, B-cell lymphoepithelial lesions, a finding commonly associated with extranodal marginal zone B-cell/mucosa-associated lymphoid tissue (MALT) lymphomas, are also often present in lymphocytic mastitis and diabetic mastopathy. Although the clinical and immunomorphologic features are well characterized, the clonality of the B-cell infiltrate and the lymphomatous potential of lymphocytic mastitis and diabetic mastopathy have not been emphasized in the literature. We evaluated 11 cases of lymphocytic mastitis/diabetic mastopathy for immunoglobulin heavy chain gene rearrangement and correlated the findings with all available clinical data. A longstanding history of Type I diabetes mellitus was present in seven patients. One nondiabetic patient had Sjogren's syndrome, and two patients had no history of diabetes mellitus or other autoimmune disease. Clinical data were unavailable for one patient. B-cell-predominant lymphoid infiltrates were seen in all cases, and B-cell lymphoepithelial lesions were found in five. No evidence of a B-cell clone was found in any of the 11 cases by appropriately controlled immunoglobulin heavy chain gene rearrangement studies, and none of the patients developed lymphoma during follow-up intervals ranging from 2-126 months. These findings suggest that despite the presence of B-cell-predominant lymphoid infiltrates and lymphoepithelial lesions, lymphocytic mastitis and diabetic mastopathy do not appear to be associated with an increased risk for lymphoma.

CD117 (KIT receptor) expression in Merkel cell carcinoma.

The KIT receptor tyrosine kinase (CD117 antigen) is found in a variety of normal tissue cell types and in several malignant tumors, including acute myeloid leukemia. We recently encountered two tumors initially suspected as acute myeloid leukemia cutis and expressing CD117 that showed punctate positivity for cytokeratin 20 diagnostic for Merkel cell carcinoma. We evaluated 20 additional cases of MCC and found that 21 of 22 tumors (95%) expressed CD117. Intensity of CD117 expression did not appear to correlate with aggressive behavior. While the function of the KIT receptor in MCC is not known, its pathogenic role in other malignant neoplasms suggests the possibility of a similar role in MCC.

Peripheral T-cell lymphoma mimicking marginal zone B-cell lymphoma.

Peripheral T-cell lymphoma (PTCL) may assume a variety of histologic and cytologic appearances. We describe eight cases of PTCL morphologically simulating marginal zone B-cell lymphoma. We reviewed PTCL cases diagnosed in our institution between 1990 and 2000 and selected eight cases for study based on the following criteria: small-cell morphology with abundant, clear cytoplasm and either marginal zone involvement by the neoplastic infiltrate in lymph node biopsies or lymphoepithelial lesions in extranodal biopsies. Histologic features and ancillary studies were reviewed. Patients included six women and two men with a median age of 53 years (range, 35 to 74 years). Six patients were diagnosed with primary nodal PTCL, and two presented with primary extranodal disease. The original diagnosis was PTCL in only four cases; three cases were diagnosed as atypical lymphoid infiltrate, and one case as benign lymphoepithelial lesion. Lymph node biopsies revealed partial effacement of the architecture with residual follicles surrounded by the neoplastic small cells. Extranodal sites included hard palate, tongue, tonsil, and submandibular glands; all but one case demonstrated lymphoepithelial lesions. Monoclonality was demonstrated in six of eight cases (rearrangement of T-cell receptor gene), and three of eight had an aberrant T-cell population by flow cytometry. The differential diagnosis of atypical lymphoid infiltrates with morphologic features of marginal zone B-cell lymphoma should include PTCL. This uncommon morphological mimicry should be recognized, because PTCL is an aggressive disease regardless of morphology and should be treated accordingly.

Cerebrospinal fluid involvement in mantle cell lymphoma.

Mantle cell lymphoma (MCL) is an aggressive neoplasm that is incurable by standard therapy. Patients often present with high-stage disease (Stages III-IV) and frequently have involvement at multiple extranodal sites. Although the gastrointestinal tract, spleen, lung, pleura, bone marrow, and peripheral blood are among the most commonly involved tissues, MCL may also disseminate to so-called sanctuary sites including the central nervous system. Despite this, current clinical evaluations do not routinely include assessment of the cerebrospinal fluid (CSF) for lymphomatous infiltrates at presentation, and moreover, only few authors have specifically examined CSF involvement in MCL. In this study, we reviewed the medical records of 108 patients with MCL seen at three centers over a 5-year period to determine the rate of CSF sampling and the frequency of CSF involvement by MCL. The clinical and cytologic characteristics associated with CSF involvement were also studied. Central nervous system (CNS) signs and/or symptoms prompted CSF sampling in 25/108 patients (23%). Specific radiographic abnormalities were present in 9/25 patients (36%). CSF involvement by MCL was identified in 10 of the 25 CSF-sampled patients (40%) by morphology (3 patients), flow cytometry alone (1 patients), or both (6 patients). The CSF-positive cases included two blastoid variants. The CSF cytology of the nine morphologically positive cases was pleomorphic, and prominent cytoplasmic granules were observed in two cases. The overall rate of CSF involvement by MCL among the cohort was 9%, which is comparable to that reported in other selected studies examining this issue.