Langerhans cell sarcoma: an unusual microscopic presentation.

A 70-year-old Caucasian male presented to our clinic for a pruritic eruption progressing over several months. He complained of fatigue with a 20-pound weight loss over the past year. On presentation, the patient had browny-yellow to violaceous, purpuric, macular and papular lesions on the legs, arms, lower abdomen and back. Initial biopsy showed an angiocentric infiltrate with a suggestion of intraluminal proliferation; CD31 and Fli-1 positivity suggested either reactive angioendotheliomatosis or an unusual intravascular histiocytosis. Further excisional biopsies demonstrated perivascular collections of cells with ample cytoplasm, prominent nuclear pleomorphism and mitotic activity. The nuclei demonstrated nuclear folding, grooves and indentations. The atypical cells were S100, CD1a and CD56 positive with immunohistochemistry. A diagnosis of Langerhans cell sarcoma (LCS) was made. LCS is a rare, aggressive malignancy that can involve multiple organs including the skin, lymph nodes, lung, bone marrow, spleen, heart, and brain. The skin and lymph nodes are commonly involved, and the cutaneous presentation varies greatly. Immunohistochemistry characteristically shows CD1a and S100 positivity. CD56 expression is uncommon and often portends a poor prognosis. There is no established treatment of LCS due to its rarity. Surgery, radiation, and chemotherapy have been used with varied outcomes. Our patient was treated with prednisone with improvement of cutaneous disease. He did not develop systemic involvement, but died 1.5 years later from complications associated with heart failure. Langerhans cell sarcoma should be considered when faced with an unusual angiocentric infiltrate in which initial immunohistochemical staining results may be misleading.

Post-transplant lymphoproliferative disorders are not associated with IgG4 sclerosing disease.

BACKGROUND: Although the majority of post-transplant lymphoproliferative disorder (PTLD) cases are associated with Epstein-Barr virus (EBV), 20-42% of cases are EBV negative (EBV-N). The antigenic stimulus that drives EBV-N PTLD is unknown, but is likely heterogeneous. A common feature of PTLD, regardless of EBV status, is an abnormal polytypic lymphoplasmacytic infiltrate. Immunglobulin-G4 (IgG4) syndrome is also characterized by a polytypic lymphoplasmacytic infiltrate with a predominance of IgG4-positive (IgG4-P) plasma cells. METHODS: We investigated the possibility of an association between EBV-N PTLD and IgG4 syndrome. Of 33 evaluated PTLD cases, 9 (27%) were EBV-N. EBV-N PTLD cases showed longer transplantation-to-diagnosis times than EBV-positive cases. RESULTS: A single patient had a preceding benign duodenal biopsy with focally prominent IgG4-P plasma cells; however, no clinical data supported IgG4 syndrome, precluding an association between IgG4 syndrome and subsequent EBV-N PTLD in this patient. CONCLUSION: As none of 29 evaluable cases of PTLD (including all 9 EBV-N cases) were associated with an increase in IgG4-P plasma cells, IgG4 syndrome does not appear to play a role in the etiology of EBV-N PTLD. The significance of these findings and the current understanding of the etiology of EBV-N PTLD are discussed.

Outbreak Risk of Club Root Caused by Plasmodiophora brassicae on Oilseed Rape in Chile.

Oilseed rape (Brassica napus L.) plants with typical club root symptoms were detected on two farms in the La Araucanía region (37°35' to 39°37' S), southern Chile. In 2010, affected plants were found in large areas throughout three fields on a single farm and disease incidence ranged from 30 to 100%. In 2013, plants with club root were found in one field on a different farm. Disease incidence in the affected areas was 30%. In both cases, affected plants showed root swellings or distortions, but no aerial symptoms were evident. Cross-sections from symptomatic roots were observed under light and fluorescent microscope and compared to healthy roots. The presence of plasmodia with resting spores in the root tissue pointed to Plasmodiophora brassicae Woronin as the causal agent. Pathogenicity was evaluated in the greenhouse. Inoculum was prepared by grinding 10 g of fresh galled roots in sterile water. The macerated tissue was filtered through sterile cheesecloth and the spore suspensions were adjusted to 1 × 107 spores/ml. Seeds of oilseed rape cv. Imminent were germinated and 5-day-old seedlings were transplanted in 250-ml pots (4 seedlings per pot). The soil surrounding the base of each seedling was inoculated with 1 ml of spore suspension. One pot received no inoculum and was used as a control. Pots were watered regularly. After 45 days, the inoculated plants showed root swelling similar to that observed in the field, whereas no symptoms were observed on the roots of the control plants. Specific PCR detection for P. brassicae was performed with pairs of primers TC1F/TC1R and TC2F/TC2R, according to the protocol described by Cao et al. (1). Total DNA was obtained from old galled roots collected in the field and galled roots from plants of the pathogenicity test, using the E.Z.N.A HP Plant DNA mini kit (Omega Biotek). Amplicon sizes of 548 and 519 bp, respectively, were obtained for each primer set, which is consistent with that reported by Cao et al. (1). Seed contamination with P. brassicae in the same seed lot used to sow the commercial field of 2013 was evaluated using the PCR method described above. Washing protocols to collect resting spores from seed was based on Rennie et al. (2). Total DNA was extracted from the resting spores pellet that had been ground in liquid nitrogen, using E.Z.N.A HP Plant DNA mini kit. PCR was performed on undiluted and diluted (1/10, 1/100, 1/1000, and 1/10000) DNA. Total DNA from a plant with gall roots where plasmodia were observed and a plant with healthy roots were used as positive and negative control, respectively. A 548-bp amplicon was amplified in the 1/10 and 1/100 dilutions with the TC1F/TC1R primers only indicating that the pathogen may have been present in the seed lot. In Chile, club root symptoms on B. napus were described in 2008 (3), though no indication of location or incidence was given. To our knowledge, this is the first confirmed case of club root disease in an oilseed rape field. This finding could prelude new cases and possibly an outbreak of club root disease on oilseed rape, jeopardizing this important crop of southern Chile. Oilseed rape production in Chile relies on imported seed of hybrids and parental materials. Although seed contamination with P. brassicae is thought to play a minor role in the epidemiology of the disease, we cannot ignore the possibility that the occurrence of this disease in 2013 may have been associated with the use of contaminated seed. References: (1) T. Cao et al. Plant Dis. 91:80, 2007. (2) D. C. Rennie et al. Plant Pathol. 60:811, 2011. (3) Rina Acuña P. Compendio de Fitopatógenos de Cultivos Agrícolas en Chile. Servicio Agrícola y Ganadero, Santiago, Chile, 2008.

Vascular implications of Dasineura sp. galls' establishment on Peumus boldus stems.

Some chewing larvae are capable of inducing galls in the host vascular cylinder, e.g. Dasineura sp. (Cecidomyiidae) on Peumus boldus stems. Due to the medicinal and economic importance of P. boldus, the anatomical and functional implications of establishment of Dasineura sp. on P. boldus stems were investigated. We asked if establishment of Dasineura sp. in P. boldus stems induces abnormalities at the cellular and organizational level of the vascular system that increase during gall development in favour of the hydric status of the gall. Anatomical alterations induced in the stems during gall development were determined. Cytohistometric analyses in mature galls were compared to non-galled stems, and water potential and leaf area of non-galled stems were compared with galled stems. Dasineura sp. establishes in the vascular cambium, leading to delignification and rupture of xylem cells, inhibiting formation of phloem and perivascular sclerenchyma. Gall diameter increases together with larval feeding activity, producing a large larval chamber and numerous layers of nutritive tissue, vascular parenchyma, and sclerenchyma. These anatomical alterations do not affect the leaf area of galled stems but favour increased water flow towards these stems. The anatomical alterations induced by Dasineura sp. in P. boldus stems guarantee water and nutrient supply to the gall and larva. After the inducer exits stems, some host branches no longer have vascular connections with the plant body.

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.

Anatomical and phenological implications of the relationship between Schinus polygama (Cav.) (Cabrera) and the galling insect Calophya rubra (Blanchard).

The success of galling insects could be determined by synchronisation with host plant phenology and climate conditions, ensuring suitable oviposition sites for gall induction and food resources for their survival. The anatomical, histochemical and phenological synchronisation strategies between Calophya rubra (Blanchard) (Hemiptera: Psylloidea) and its host, the evergreen plant Schinus polygama (Cav.) (Cabrera) (Anacardiaceae), in the Mediterranean climate of southern Chile was evaluated and compared to that of the congeneric C. cf. duvauae (Scott) from Brazil and closely related host plant S. engleri in a subtropical climate. Anatomical, histometric, histochemical and vegetative phenology studies of the stem and galls were conducted from June 2015 to December 2016. Based on the anatomical, histometric and histochemical analysis, the conical stem gall traits imply gains over the non-galled stem toward the galling insect survival, but the maintenance of phellem, secretory ducts and pith indicate conservative developmental traits that cannot be manipulated by C. rubra. Our results indicate that the conditions of the Mediterranean climate zone limit C. rubra immature activity during unfavourable periods, probably determining a diapause period and a univoltine life cycle, which are peculiarities of the S. polygama- C. rubra system. The synchronisation between development and seasonality confers peculiarities to the S. polygama- C. rubra system in the Mediterranean climate zone.

Neuronal expression of a thyroid hormone receptor α mutation alters mouse behaviour.

In humans, alterations in thyroid hormone signalling are associated with mood and anxiety disorders, but the neural mechanisms underlying such association are poorly understood. The present study investigates the involvement of neuronal thyroid hormone receptor α (TRα) in anxiety, using mouse genetics and Cre/loxP technology to specifically alter TRα signalling in neurons. We evaluated the behaviour of mice expressing a dominant negative, neuron-specific mutation of TRα (TRαAMI/Cre3 mice), using the elevated-plus maze, light-dark box and open-field tests. In a first experiment, mice were housed individually, and the behaviour of TRαAMI/Cre3 mice differed significantly from that of control littermates in these 3 tests, suggesting heightened anxiety. In a second experiment, designed to evaluate the robustness of the results with the same 3 tests, mice were housed in groups. In these conditions, the behaviour of TRαAMI/Cre3 mice differed from that of control littermates only in the light-dark box. Thus, TRαAMI/Cre3 mice appear to be more likely to develop anxiety under stressful housing conditions than control mice. These results suggest that in adult mice, thyroid hormone signalling in neurons, via TRα, is involved in the control of anxiety behaviour.

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.

Extraversion and inhibition: a slow-potential study.

This report presents data showing that extroverts (Eysenck Personality Inventory) develop larger positive vertex slow potentials than introverts under extinction conditions ("no go" instruction in a fixed foreperiod reaction time task). The effect was clearer in subjects with low neuroticism (N) scores than in those with a middle N level. Since independent evidence indicates that cortical positivity is associated with inhibitory phenomena, results are interpreted as lending support to the notion that extroverts may develop more inhibitory potential than introverts under certain conditions.

Is lymphoplasmacytic lymphoma/immunocytoma a distinct entity? A clinicopathologic study of 20 cases.

Lymphoplasmacytic lymphoma/immunocytoma (LLI) was defined initially as a small B-cell lymphoma with plasmacytoid or plasmacytic features. Because other types of small B-cell lymphoma, particularly marginal zone B-cell lymphoma may exhibit plasmacytic differentiation, the revised European-American lymphoma classification and World Health Organization has defined LLI more narrowly to exclude other small B-cell lymphomas. The goal of this study was to reevaluate LLI as a clinicopathologic entity. Twenty cases were selected from 43 previously diagnosed as "small lymphocytic lymphoma, plasmacytoid" or "immunocytoma" from 1985 to 1998. Cases fulfilling the criteria for B-cell small lymphocytic lymphoma, follicular lymphoma, marginal zone B-cell lymphoma, or other types of B-cell lymphoma were excluded. The histopathology and immunoreactivity for CD20, CD79a, CD3, CD43, CD23, CD5, kappa, lambda, and immunoglobulins (Ig's) M, G, and A were reviewed, in addition to available clinical findings. There were 13 men and seven women, with a mean age of 69 years. Five patients had documented Waldenström's macroglobulinemia (WM). Three architectural patterns were observed. Pattern A (seven of 20) showed open sinuses, small follicles, and hemosiderosis; pattern B (four of 20) showed hyperplastic follicles; and pattern C (nine of 20) showed diffuse effacement. Epithelioid histiocytes were prominent in patterns B and C but absent in A. Cytologically, six of 20 were polymorphous with 10% to 40% transformed cells; 14 of 20 were lymphoplasmacytic. Five cases showed minor foci of monocytoid B cells. One case showed a composite histology of LLI and small lymphocytic lymphoma. Amyloid was present in two cases. All cases were CD20 and/or CD79a immunoreactive, with two of 20 positive for CD43. Twelve cases were kappa monoclonal and eight cases were lambda monoclonal. Twelve of 17 cases that could be evaluated were positive for IgM and five were positive for IgG. All cases were negative for CD5 and CD23 with the exception of the one case with a composite histology. Eleven of 20 patients with available follow-up died of disease (median, 48 months), and eight of 20 are alive with disease at a follow-up of 6 months to 2 years. LLI does appear to represent a distinct clinicopathologic entity even though it shows morphologic heterogeneity and overlapping features with marginal zone B-cell lymphoma and small lymphocytic lymphoma. Recognition of LLI is important because the overall prognosis may be worse than for other types of small B-cell lymphomas.

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.

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.

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.

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.

Specific respiratory patterns distinguish among human basic emotions.

Prototypical respiratory-facial-postural actions ('emotional effector patterns') related to six basic emotions had been extracted from an ensemble of physiological reactions present in subjects reliving intense emotional situations (Bloch & Santibañez, 1972). Subjects reproducing these actions could evoke the corresponding subjective experience, which suggested their use as an experimental model for generating controlled emotional states. The aim of the present study was to quantify the respiratory parameters which characterize the emotions of joy-laughter, sadness-crying, fear-anxiety, anger, erotic love and tenderness. Respiratory movements and facial/postural expressions were recorded from 36 young actors who had learned in previous workshops to express these emotions by reproducing the corresponding prototypical actions. A qualitative analysis of the recordings showed that as the emotional reproduction went along, both breathing and expression evolved from an initial 'robot-like' phase to a more natural stage in which spontaneous vocalizations and gestures appeared. This suggested a partial activation of the emotional network. The quantitative analysis of the respiratory movements for the fundamental cycles showed that for anger, erotic love and tenderness significant changes in amplitude, rate and duration of the 'expiratory pause' were the major elements of differentiation, while for sadness, joy and fear inspiratory over expiratory time ratios were the elements of differentiation. These last three emotions were further characterized by small amplitude/high rate saccadic respiratory movements superposed to different phases of the fundamental cycles. It is concluded that quantitatively well differentiated sets of respiratory changes characterize each of six basic emotions. The bottom-up experimental model for generating such emotions based on the joint activation of the respiratory-facial-postural systems and its relation to corresponding 'real-life' emotions is discussed.

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.

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.

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.

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.

Cell surface phenotype and cytokine secretion in Caco-2 cell cultures: increased RANTES production and IL-2 transcription upon stimulation with IL-1beta.

Caco-2 is a colonic tumour cell line which, when cultured, spontaneously exhibits enterocyte-like characteristics. Given the difficulties in maintaining long-lasting cultures of enterocytes, this cell line may be a suitable in vitro model to carry out experiments trying to delineate the involvement of enterocytes in local immune responses, and their role in pathology. It seems then reasonable to obtain a detailed immune analysis of Caco-2, and compare it with available data on enterocytes. Cytofluorometry revealed several leukocyte markers on Caco-2, present also on human enterocytes. These markers include surface proteases (CD10, CD13 and CD26), antigen-presenting cell markers (CD13, CD14, CD35 and CD63), integrins (CD18 and CD61), epithelial/endothelial markers (CD21, CD31, CD47 and CD59) and finally, CD25 and CD28. In contrast to enterocytes, HLA-class 11 molecules are not found on Caco-2, whether resting or gamma-IFN-stimulated. Moreover, culture experiments with allogeneic lymphocytes revealed that Caco-2 cells were unable to induce their proliferation. Cytokine analysis showed an increased RANTES synthesis and IL-2 transcription upon stimulation with IL-1beta. Finally, amongst RANTES receptors, CCR1 is found on Caco-2 cells, whereas CCR3 and CCR5 are not.