Basophils as a potential therapeutic target in cancer.

Basophils, which are considered as redundant relatives of mast cells and the rarest granulocytes in peripheral circulation, have been neglected by researchers in the past decades. Previous studies have revealed their vital roles in allergic diseases and parasitic infections. Intriguingly, recent studies even reported that basophils might be associated with cancer development, as activated basophils synthesize and release a variety of cytokines and chemokines in response to cancers. However, it is still subject to debate whether basophils function as tumor-protecting or tumor-promoting components; the answer may depend on the tumor biology and the microenvironment. Herein, we reviewed the role of basophils in cancers, and highlighted some potential and promising therapeutic strategies.

A new score including CD43 and CD180: Increased diagnostic value for atypical chronic lymphocytic leukemia.

Moreau score has been used to differentiate chronic lymphocytic leukemia (CLL) from other mature B-cell neoplasms. However, it showed limitations in Asian patients. Therefore, we conducted a new score system replacing CD5 and CD23 with CD43 and CD180 to evaluate its diagnostic value of CLL. 237 untreated samples diagnosed with mature B-cell neoplasms were collected and were randomly divided into an exploratory and a validation cohort by a 2:1 ratio. The expression of CD5, CD19, CD20, CD23, CD43, CD79b, CD180, CD200, FMC7, and surface immunoglobulin (SmIg) were analyzed among all the samples. A proposed score was developed based on the logistic regression model. The sensitivity and specificity of the proposed score were calculated by ROC curves. CD43/CD180, CD200, FMC7, and CD79b were included in our new CLL score, which showed a sensitivity of 91.8% and a specificity of 83.1%. These results were confirmed in a validation cohort with a sensitivity of 90.5% (p = 0.808) and a specificity of 79.5% (p = 0.639). In CD5 negative or CD23 negative CLL group, the new CLL score displayed improved sensitivity of 79.4% compared to Moreau score and CLLflow score (41.2% and 47.1%, respectively). In atypical CLL group, the new CLL score showed improved sensitivity of 84.2% compared to Moreau score and CLLflow score (61.4% and 64.9%, respectively). This proposed atypical CLL score helped to offer an accurate differentiation of CLL from non-CLL together with morphological and molecular methods, particularly in Chinese patients with atypical immunophenotype.

Identification of Murine Basophils by Flow Cytometry and Histology.

Here, we describe how murine basophils can be detected in vivo by flow cytometry and immunofluorescence staining. Basophils constitute a homogeneous population of CD4-CD19-CD49b+IgE+ cells in flow cytometric analysis. When IgE levels are low, one can also use anti-FcεRI or anti-CD200R3 antibodies instead of anti-IgE. For immunofluorescence staining, we use an anti-Mcpt8 antibody since Mcpt8 is a specific marker for murine basophils. We describe how to prepare the tissue to cut cryo-sections and how to perform the staining using a tyramide-based amplification kit.

Reduced Nhe1 (Na+-H+ Exchanger-1) Function Protects ApoE-Deficient Mice From Ang II (Angiotensin II)-Induced Abdominal Aortic Aneurysms.

IgE-mediated activation of Nhe1 (Na+-H+ exchanger-1) induces aortic cell extracellular acidification and promotes cell apoptosis. A pH-sensitive probe pHrodo identified acidic regions at positions of macrophage accumulation, IgE expression, and cell apoptosis in human and mouse abdominal aortic aneurysm (AAA) lesions. Ang II (angiotensin II)-induced AAA in Nhe1-insufficient Apoe-/-Nhe1+/- mice and Apoe-/-Nhe1+/+ littermates tested Nhe1 activity in experimental AAA, because Nhe1-/- mice develop ataxia and epileptic-like seizures and die early. Nhe1 insufficiency reduced AAA incidence and size, lesion macrophage and T-cell accumulation, collagen deposition, elastin fragmentation, cell apoptosis, smooth muscle cell loss, and MMP (matrix metalloproteinase) activity. Nhe1 insufficiency also reduced blood pressure and the plasma apoptosis marker TCTP (translationally controlled tumor protein) but did not affect plasma IgE. While pHrodo localized the acidic regions to macrophage clusters, IgE expression, and cell apoptosis in AAA lesions from Apoe-/-Nhe1+/+ mice, such acidic areas were much smaller in lesions from Apoe-/-Nhe1+/- mice. Nhe1-FcεR1 colocalization in macrophages from AAA lesions support a role of IgE-mediated Nhe1 activation. Gelatin zymography, immunoblot, and real-time polymerase chain reaction analyses demonstrated that Nhe1 insufficiency reduced the MMP activity, cysteinyl cathepsin expression, IgE-induced apoptosis, and NF-κB activation in macrophages and blocked IgE-induced adhesion molecule expression in endothelial cells. A near-infrared fluorescent probe (LS662) together with fluorescence reflectance imaging of intact aortas showed reduced acidity in AAA lesions from Nhe-1-insufficient mice. This study revealed extracellular acidity at regions rich in macrophages, IgE expression, and cell apoptosis in human and mouse AAA lesions and established a direct role of Nhe1 in AAA pathogenesis.

The Intersection of IgE Autoantibodies and Eosinophilia in the Pathogenesis of Bullous Pemphigoid.

Bullous pemphigoid (BP) is an autoimmune blistering disease characterized by autoantibodies targeting cellular adhesion molecules. While IgE autoantibodies are occasionally reported in other autoimmune blistering diseases, BP is unique in that most BP patients develop an IgE autoantibody response. It is not known why BP patients develop self-reactive IgE and the precise role of IgE in BP pathogenesis is not fully understood. However, clinical evidence suggests an association between elevated IgE antibodies and eosinophilia in BP patients. Since eosinophils are multipotent effector cells, capable cytotoxicity and immune modulation, the putative interaction between IgE and eosinophils is a primary focus in current studies aimed at understanding the key components of disease pathogenesis. In this review, we provide an overview of BP pathogenesis, highlighting clinical and experimental evidence supporting central roles for IgE and eosinophils as independent mediators of disease and via their interaction. Additionally, therapeutics targeting IgE, the Th2 axis, or eosinophils are also discussed.

Divergent immunohistochemical expression of CD21 and CD23 by follicular dendritic cells with increasing grade of follicular lymphoma.

BACKGROUND: Ultrastructural and immunohistochemical differences have been described in FDCs of primary and secondary follicles, illustrating the highly compartmentalized structure of lymph follicles. Differences in FDC immunophenotype in different grades of FL may reflect some parallelism between reactive and neoplastic conditions in terms of FDC-B cell interaction and may be used as a valuable additional tool for grading FL. METHODS: A total of 60 paraffin blocks from patients with follicular lymphoma, 30 cases each of grade 1 and 3, were retrieved from our archive. Immunohistochemical analysis was carried out for CD21, CD23, cyclin A, and Ki-67. RESULTS: Our study demonstrates that during evaluation, six patterns of FDC distribution were distinguished. The intensity of stain for CD21 was not statistically significant in grade 1 and grade 3 FL (p = 0.340). In contrast, grade 3 FLs exhibited a significant decrease of CD23 expression by the FDCs (p < 0.001). By CD21 stain, there was no significant difference in the distribution of pattern 1 in grades 1 and 3 (p = 0.098). In contrast, in grade 3, this pattern was significantly less observed by CD23 stain (p = 0.016). The same was observed for pattern 2 for CD21 (p = 0.940) and CD23 (p = 0.010) and pattern 4 for CD21 (p = 0.305) and CD23 (p = 0.005), respectively. Distribution of pattern 5 was significantly different between grades 1 and 3 both for CD21 (p = 0.005) and CD23 (p < 0.001). Distribution of patterns 2 and 6 was not significantly different between grades 1 and 3 for CD21 and CD23. The values of cyclin A and Mib-1 were also significantly different between grades 1 and 3 (p < 0.001). CONCLUSIONS: The observed patterns of FDCs lead us to believe that similar to reactive lymph node follicles, neoplastic follicles in FL, at least in early stages, have an organized structure. Hypothetically, with CD21, CD23, and cyclin A immunohistochemistry, the sequence of events in FL progression may be traced.

SOX11-negative Mantle Cell Lymphoma: Clinicopathologic and Prognostic Features of 75 Patients.

Studies have suggested that SOX11 expression has prognostic implications in patients with mantle cell lymphoma (MCL), but the data are controversial. In this study, we describe the clinicopathologic and prognostic features of 75 patients with SOX11-negative MCL. Compared with patients with SOX11-positive MCL, SOX11-negative MCL patients more frequently had leukemic non-nodal disease (21% vs. 4%, P=0.0001). SOX11-negative MCLs more often showed classic morphology (83% vs. 65%, P=0.005), were more often positive for CD23 (39% vs. 22%, P=0.02) and CD200 (60% vs. 9%, P=0.0001), and had a lower proliferation index (Ki67 23% vs. 33%, P=0.04). Overall survival (OS) was not significantly different between patients with SOX11-negative versus SOX11-positive MCL (P=0.63). High Ki67 index and blastoid/pleomorphic morphology were associated with shorter OS in both SOX11-negative (P<0.05) and SOX11-positive MCL groups (P<0.05). A high Mantle Cell Lymphoma International Prognostic Index (MIPI) predicted poorer prognosis in patients with SOX11-negative MCL (P<0.0001), but not SOX11-positive MCL (P=0.09). Nodal involvement and stage III/IV disease were associated with poorer outcome in patients with SOX11-positive MCL (P=0.03 and 0.04, respectively), but not SOX11-negative MCL (P=0.88 and 0.74, respectively). In summary, SOX11-negative MCL is characterized by more frequent leukemic non-nodal disease, classic morphology, more frequent expression of CD23 and CD200, and a lower Ki67 index. Prognostic factors in patients with SOX11-negative MCL include morphology, Ki67 index, and MIPI score.

Lymphoma-like monoclonal B cell lymphocytosis in a patient population: biology, natural evolution, and differences from CLL-like clones.

High-count monoclonal B cell lymphocytosis (MBL) with a chronic lymphocytic leukemia (CLL) phenotype is a well-known entity, featuring 1-4% annual risk of progression towards CLL requiring treatment. Lymphoma-like MBL (L-MBL), on the other hand, remains poorly defined and data regarding outcome are lacking. We retrospectively evaluated 33 L-MBL cases within our hospital population and compared them to 95 subjects with CLL-like MBL (C-MBL). Diagnoses of L-MBL were based on asymptomatic B cell clones with Matutes score < 3, B cells < 5.0 × 103/µl, and negative computerized tomography scans. We found that median B cell counts were considerably lower compared to C-MBL (0.6 vs 2.3 × 103/µl) and remained stable over time. Based on immunophenotyping and immunogenetic profiling, most L-MBL clones did not correspond to known lymphoma entities. A strikingly high occurrence of paraproteinemia (48%), hypogammaglobulinemia (45%), and biclonality (21%) was seen; these incidences being significantly higher than in C-MBL (17, 21, and 5%, respectively). Unrelated monoclonal gammopathy of undetermined significance was a frequent feature, as the light chain type of 5/12 paraproteins detected was different from the clonal surface immunoglobulin. After 46-month median follow-up, 2/24 patients (8%) had progressed towards indolent lymphoma requiring no treatment. In contrast, 41% of C-MBL cases evolved to CLL and 17% required treatment. We conclude that clinical L-MBL is characterized by pronounced immune dysregulation and very slow or absent progression, clearly separating it from its CLL-like counterpart.

[The culture of murine fetal skin-derived mast cells].

Objective To isolate, induce and culture murine fetal skin-derived mast cells. Methods Day 14-16 murine fetal skin cells were separated and cultured in the presence of recombinant mouse interleukin-3 (rmIL-3) and recombinant mouse stem cell factor (rmSCF) to induce the maturation of mast cells. After cultured for 2 weeks, the mast cells were obtained by gradient centrifugation. The cells were stained with toluidin blue or anti-mast cell tryptase antibody to identify the purity. FcepsilonR I and CD117, which were the surface markers of mature mast cells, were identified with flow cytometry. Results After cultured for 14 days and purified, the cytoplasm was observed filled with typical granules using toluidin blue staining or with tryptase positive substance using immunocytochemistry. The expression of FcepsilonRIand CD117 was found in 97% cells. Conclusion Murine fetal skin-derived mast cells were cultured successfully and a large number of highly purified mast cells were obtained.

p16 expression in follicular dendritic cell sarcoma: a potential mimicker of human papillomavirus-related oropharyngeal squamous cell carcinoma.

Follicular dendritic cell sarcoma is a rare mesenchymal neoplasm that most commonly occurs in cervical lymph nodes. It has histologic and clinical overlap with the much more common p16-positive human papillomavirus (HPV)-related squamous cell carcinoma of the oropharynx, which characteristically has nonkeratinizing morphology and often presents as an isolated neck mass. Not surprisingly, follicular dendritic cell sarcomas are commonly misdiagnosed as squamous cell carcinoma. Immunohistochemistry is helpful in separating the 2 entities. Follicular dendritic cell sarcoma expresses dendritic markers such as CD21 and CD23 and is almost always cytokeratin negative. However, in many cases of HPV-related oropharyngeal carcinoma, only p16 immunohistochemistry as a prognostic and surrogate marker for HPV is performed. p16 expression in follicular dendritic cell sarcoma has not been characterized. Here, we investigate the expression of p16 in follicular dendritic cell sarcoma and correlate it with retinoblastoma protein expression. A pilot study of dendritic marker expression in HPV-related oropharyngeal squamous cell carcinoma was also performed. We found that 4 of 8 sarcomas expressed p16 with strong and diffuse staining in 2 cases. In 2 of the 4 cases, p16 expression corresponded to loss of retinoblastoma protein expression. Dendritic marker expression (CD21 and CD23) was not found in HPV-related oropharyngeal squamous cell carcinomas. As such, positive p16 immunohistochemistry cannot be used as supportive evidence for the diagnosis of squamous cell carcinoma as strong and diffuse p16 expression may also occur in follicular dendritic cell sarcoma. Cytokeratins and dendritic markers are critical in separating the two tumor types.

Clinical efficacy of omalizumab in chronic spontaneous urticaria is associated with a reduction of FcεRI-positive cells in the skin.

Background. Treatment with omalizumab, a humanized recombinant monoclonal anti-IgE antibody, results in clinical efficacy in patients with Chronic Spontaneous Urticaria (CSU). The mechanism of action of omalizumab in CSU has not been elucidated in detail. Objectives. To determine the effects of omalizumab on levels of high affinity IgE receptor-positive (FcεRI+) and IgE-positive (IgE+) dermal cells and blood basophils. Treatment efficacy and safety were also assessed. Study design. In a double-blind study, CSU patients aged 18­75 years were randomized to receive 300 mg omalizumab (n=20) or placebo (n=10) subcutaneously every 4 weeks for 12 weeks. Changes in disease activity were assessed by use of the weekly Urticaria Activity Score (UAS7). Circulating IgE levels, basophil numbers and levels of expression of FcεRI+ and IgE+ cells in the skin and in blood basophils were determined. Results. Patients receiving omalizumab showed a significantly greater decrease in UAS7 compared with patients receiving placebo. At Week 12 the mean difference in UAS7 between treatment groups was -14.82 (p=0.0027), consistent with previous studies. Total IgE levels in serum were increased after omalizumab treatment and remained elevated up to Week 12. Free IgE levels decreased after omalizumab treatment. Mean levels of FcεRI+ skin cells in patients treated with omalizumab 300 mg were decreased at Week 12 compared with baseline in the dermis of both non-lesional and lesional skin, reaching levels comparable with those seen in healthy volunteers (HVs). There were no statistically significant changes in mean FcɛRI+ cell levels in the placebo group. Similar results were seen for changes in IgE+ cells, although the changes were not statistically significant. The level of peripheral blood basophils increased immediately after treatment start and returned to Baseline values after the follow-up period. The levels of FcεRI and IgE expression on peripheral blood basophils were rapidly reduced by omalizumab treatment up to Week 12. Conclusions. Treatment with omalizumab resulted in rapid clinical benefits in patients with CSU. Treatment with omalizumab was associated with reduction in FcɛRI+ and IgE+ basophils and intradermal cells.

Characterization of a variant of t(14;18) negative nodal diffuse follicular lymphoma with CD23 expression, 1p36/TNFRSF14 abnormalities, and STAT6 mutations.

A predominantly diffuse growth pattern and CD23 co-expression are uncommon findings in nodal follicular lymphoma and can create diagnostic challenges. A single case series in 2009 (Katzenberger et al) proposed a unique morphologic variant of nodal follicular lymphoma, characterized by a predominantly diffuse architecture, lack of the t(14;18) IGH/BCL2 translocation, presence of 1p36 deletion, frequent inguinal lymph node involvement, CD23 co-expression, and low clinical stage. Other studies on CD23+ follicular lymphoma, while associating inguinal location, have not specifically described this architecture. In addition, no follow-up studies have correlated the histopathologic and cytogenetic/molecular features of these cases, and they remain a diagnostic problem. We identified 11 cases of diffuse, CD23+ follicular lymphoma with histopathologic features similar to those described by Katzenberger et al. Along with pertinent clinical information, we detail their histopathology, IGH/BCL2 translocation status, lymphoma-associated chromosomal gains/losses, and assessment of mutations in 220 lymphoma-associated genes by massively parallel sequencing. All cases showed a diffuse growth pattern around well- to ill-defined residual germinal centers, uniform CD23 expression, mixed centrocytic/centroblastic cytology, and expression of at least one germinal center marker. Ten of 11 involved inguinal lymph nodes, 5 solely. By fluorescence in situ hybridization analysis, the vast majority lacked IGH/BCL2 translocation (9/11). Deletion of 1p36 was observed in five cases and included TNFRSF14. Of the six cases lacking 1p36 deletion, TNFRSF14 mutations were identified in three, highlighting the strong association of 1p36/TNFRSF14 abnormalities with this follicular lymphoma variant. In addition, 9 of the 11 cases tested (82%) had STAT6 mutations and nuclear P-STAT6 expression was detectable in the mutated cases by immunohistochemistry. The proportion of STAT6 mutations is higher than recently reported in conventional follicular lymphoma (11%). These findings lend support for a clinicopathologic variant of t(14;18) negative nodal follicular lymphoma and suggests importance of the interleukin (IL)-4/JAK/STAT6 pathway in this variant.

Mast cell differentiation: still open questions?

In this issue of Blood, Dahlin et al report on a minor circulating human mast cell (MC) progenitor cell population (lineage-negative [Lin−]/CD34hi/CD117int/hi/high-affinity immunoglobulin E receptor-positive [FcεRI+]), with an immature MC-like appearance, which is present in the peripheral blood (PB) of healthy individuals and of asthma subjects well controlled by treatment or with reduced lung function.

IgE low affinity receptor (CD23) expression, Plasmodium falciparum specific IgE and tumor necrosis factor-alpha production in Thai uncomplicated and severe falciparum malaria patients.

Previous studies have suggested that Plasmodium falciparum (P. falciparum) specific IgE in the form of immune complexes crosslinking the low-affinity receptor (CD23) on monocyte results in tumor necrosis factor (TNF)-α and nitric oxide (NO) production. However, the roles of these parameters in severity and immune protection are still unclear. This study aimed to determine the association between CD23 expression on monocytes, plasma soluble CD23 (sCD23), total IgE, malaria-specific IgE and IgG, and TNF-α levels in P. falciparum infected patients. We evaluated 64 uncomplicated (UC) and 25 severe patients (S), admitted at the Hospital for Tropical Diseases, Mahidol University, and 34 healthy controls (C) enrolled in 2001. Flow cytometry and enzyme linked immunosorbent assays (ELISA) demonstrated that trends of the CD23 expression, levels of sCD23 and specific IgE were higher in the S group as compared to those in the UC and C groups. Plasma levels of P. falciparum specific IgE in the UC (p=0.011) and S groups (p=0.025) were significantly higher than those in C group. In contrast the TNF-α levels tended to be higher in the UC than those in the S (p=0.343) and significantly higher than those in C (p=0.004) groups. The specific IgG levels in UC were significantly higher than those in S and C (p<0.001) groups. At admission, a strong significant negative correlation was found between specific IgG and sCD23 (r=-0.762, p=0.028), and TNF-α and IgE-IgG complexes (r=-0.715, p=0.002). Significant positive correlations between levels of specific IgE and TNF-α (r=0.575, p=0.010); and sCD23 (r=0.597, p=0.000) were also observed. In conclusion, our data suggest that CD23 expression and malaria-specific IgE levels may be involved in the severity of the disease while TNF-α and the malaria-specific IgG may correlate with protection against falciparum malaria.

Lin- CD34hi CD117int/hi FcεRI+ cells in human blood constitute a rare population of mast cell progenitors.

Mast cells are rare tissue-resident immune cells that are involved in allergic reactions, and their numbers are increased in the lungs of asthmatics. Murine lung mast cells arise from committed bone marrow-derived progenitors that enter the blood circulation, migrate through the pulmonary endothelium, and mature in the tissue. In humans, mast cells can be cultured from multipotent CD34(+) progenitor cells. However, a population of distinct precursor cells that give rise to mast cells has remained undiscovered. To our knowledge, this is the first report of human lineage-negative (Lin(-)) CD34(hi) CD117(int/hi) FcεRI(+) progenitor cells, which represented only 0.0053% of the isolated blood cells in healthy individuals. These cells expressed integrin ß7 and developed a mast cell-like phenotype, although with a slow cell division capacity in vitro. Isolated Lin(-) CD34(hi) CD117(int/hi) FcεRI(+) blood cells had an immature mast cell-like appearance and expressed high levels of many mast cell-related genes as compared with human blood basophils in whole-transcriptome microarray analyses. Furthermore, serglycin, tryptase, and carboxypeptidase A messenger RNA transcripts were detected by quantitative reverse transcription-polymerase chain reaction. Altogether, we propose that the Lin(-) CD34(hi) CD117(int/hi) FcεRI(+) blood cells are closely related to human tissue mast cells and likely constitute an immediate precursor population, which can give rise to predominantly mast cells. Furthermore, asthmatics with reduced lung function had a higher frequency of Lin(-) CD34(hi) CD117(int/hi) FcεRI(+) blood mast cell progenitors than asthmatics with normal lung function.

Phenotypic variability in human skin mast cells.

Mast cells (MCs) are unique constituents of the human body. While inter-individual differences may influence the ways by which MCs operate in their skin habitat, they have not been surveyed in a comprehensive manner so far. We therefore set out to quantify skin MC variability in a large cohort of subjects. Pathophysiologically relevant key features were quantified and correlated: transcripts of c-kit, FcεRIα, FcεRIß, FcεRIγ, histidine decarboxylase, tryptase, and chymase; surface expression of c-Kit, FcεRIα; activity of tryptase, and chymase; histamine content and release triggered by FcεRI and Ca(2+) ionophore. While there was substantial variability among subjects, it strongly depended on the feature under study (coefficient of variation 33-386%). Surface expression of FcεRI was positively associated with FcεRIα mRNA content, histamine content with HDC mRNA, and chymase activity with chymase mRNA. Also, MC signature genes were co-regulated in distinct patterns. Intriguingly, histamine levels were positively linked to tryptase and chymase activity, whereas tryptase and chymase activity appeared to be uncorrelated. FcεRI triggered histamine release was highly variable and was unrelated to FcεRI expression but unexpectedly tightly correlated with histamine release elicited by Ca(2+) ionophore. This most comprehensive and systematic work of its kind provides not only detailed insights into inter-individual variability in MCs, but also uncovers unexpected patterns of co-regulation among signature attributes of the lineage. Differences in MCs among humans may well underlie clinical responses in settings of allergic reactions and complex skin disorders alike.

Blastic marginal zone lymphoma: a clinical and pathological study of 8 cases and review of the literature.

INTRODUCTION: Blastic transformation (BT) of marginal zone lymphoma or mucosa-associated lymphoid tissue lymphoma has been mainly reported in the spleen and stomach. Primary cutaneous marginal zone lymphoma that undergoes BT is rare and not well documented. We describe 8 patients with blastic primary cutaneous marginal zone lymphoma and compare the clinical, pathologic, and molecular findings of these patients with 10 cases previously reported in the literature. RESULTS: The cases of blastic marginal zone lymphoma could be categorized into cases of de novo blastic marginal zone lymphoma and large-cell transformation arising in a background of a history of biopsy proven marginal zone lymphoma. The cases of de novo blastic marginal zone lymphoma occurred in elderly patients without any medical history. In each of the cases, the lesions were radiated, not treated, or treated with complete excision without any death due to lymphoma nor was there any evidence of extracutaneous dissemination. Large-cell transformation arising in background of marginal zone lymphoma typically occurred in patients who were younger; 2 of the 4 cases were immunocompromised. The clinical course in each of the cases was aggressive with 3 of the 4 patients succumbing to disseminated disease while 1 patient developed extracutaneous nodal disease. Phenotypically, there was an expression of CD5 in a total of 3 of the 8 cases and CD23 in 3 of the 8 cases. Commonality of B-cell clones was demonstrated in 2 cases where biopsies were available of both the less aggressive appearing marginal zone lymphoma and the transformed biopsies. Cytogenetic abnormalities associated with BT included a deletion of chromosome 7q in all cases tested. CONCLUSION: Large-cell transformation arising in a patient with a history of marginal zone lymphoma portends a worse prognosis, including death from disseminated disease, whereas a de novo presentation of blastic marginal zone lymphoma may define a clinical course similar to other forms of low-grade cutaneous B-cell lymphoma. The expression of CD5 and CD23 may define a phenotypic profile associated with BT. It is possible that marginal zone lymphomas associated with CD5 and CD23 positivity should be followed more closely and/or treated with radiation and/or complete excision.

[Chronic lymphocytic leukaemia presenting with specific cutaneous infiltrates in the absence of lymphocytosis: Two cases]. / Leucémie lymphoïde chronique révélée par des infiltrats cutanés spécifiques en l'absence d'hyperlymphocytose : deux observations.

BACKGROUND: Specific cutaneous infiltrates of chronic lymphocytic leukaemia (CLL) are rare. They occur after a mean disease duration of 3 years. CLL skin infiltrates as the primary manifestation of the disease have been reported, but a normal lymphocyte count at diagnosis is rare. We present two cases of CLL initially presenting in the skin, without lymphocytosis. PATIENTS AND METHODS: A 53-year-old man developed papulonodular lesions of the face and infiltrated plaques of the scalp, and an 85-year-old woman presented erythematous nodules of the face and neck. Histopathology revealed a lymphocytic infiltrate, consisting of small mature B-cells CD20+, CD79+, with an aberrant phenotype CD5+. CD23 was positive in one case. The two patients had no lymphocytosis, but immunophenotyping was characteristic of CLL. In the second case, there was a sub-mental adenopathy, histologic analysis of which was consistent with CLL. The CLL was classified as Binet stage A in the two cases. No disease progression was noted at follow-up. DISCUSSION: The unusual feature of these cases is the lack of lymphocytosis at diagnosis. Thus, the skin lesions resulted in further evaluations for CLL, although the diagnosis was not suggested by the blood count. CONCLUSION: Skin involvement in CLL does not appear to be a poor prognostic indicator, arguing in favour of recruitment of circulating monoclonal B-cells rather than an additional tumour mass.