Biomedical subjects

T P Singleton

Publications and source records attributed to T P Singleton.

At least 19 recordsLinked to original sources

PubMed2001

Acute cytomegalovirus infection complicated by vascular thrombosis: a case report.

We present a case report of a previously healthy adult with cytomegalovirus infection that was complicated by extensive mesenteric arterial and venous thrombosis. To our knowledge, this is the first reported case of this syndrome in an immunocompetent individual who had no predisposing risk factors for thrombosis, and it demonstrates the propensity for cytomegalovirus to be involved in vascular disease.

Acute Disease↗

PubMed2001

Adhesion molecule expression in CD5-negative/CD10-negative chronic B-cell leukemias: comparison with non-Hodgkin's lymphomas and CD5-positive B-cell chronic lymphocytic leukemia.

The classification of CD5-negative/CD10-negative chronic B-cell leukemias (CD5-/CD10- CBL) can be problematic. Most of these cases may represent leukemic non-Hodgkin's lymphoma (NHL) other than B-cell chronic lymphocytic leukemia (BCLL); nonetheless, some investigators still advocate the term "CD5-negative BCLL." Because adhesion molecule (AdMol) expression patterns reflect the biology of lymphoid neoplasms, we studied a series of 106 B-cell lymphoproliferative disorders, including CD5+ BCLL (n = 56), NHL other than BCLL (n = 35), and CD5-/CD10- CBL (excluding hairy cell leukemia and prolymphocytic leukemia) with no prior history of NHL (n = 15) for expression of components of the very late antigen-4 complex (alpha4/beta1 integrin (CD49d/CD29)), components of the mucosal addressin-cell adhesion molecule receptor (alpha4(CD49d)/beta7 integrin), and L-selectin (CD62L). CD62L expression was significantly greater in CD5+ BCLL than in NHL (P < .001). Conversely, CD29, CD49d, and beta7-integrin expression were significantly greater in NHL than in CD5+ BCLL (P < .001 for each marker). These differences persisted when only blood and bone marrow samples were analyzed, with the exception of differences in CD62L expression, which approached, but did not reach, statistical significance (P = .08). The group of CD5-/CD10- CBL displayed an AdMol profile similar to NHL and was significantly different than CD5+ BCLL in expression of beta7 integrin, CD29, CD49d, and CD62L (P range < .001-.011). In summary, CD5-/CD10- CBL display an AdMol profile resembling NHL and significantly different from CD5+ BCLL, supporting the growing notion that "CD5-negative BCLL" generally represents leukemic NHL rather than a variant of true CD5+ BCLL.

Adult↗

PubMed2001

Waldenström macroglobulinemia caused by extranodal marginal zone B-cell lymphoma: a report of six cases.

Waldenström macroglobulinemia (WM) and its associated hyperviscosity syndrome (HVS) are generally caused by lymphoplasmacytoid lymphoma or other small B-cell lymphoproliferative disorders. WM associated with extranodal marginal zone B-cell-mucosa-associated lymphoid tissue lymphoma (EMZL/MALT-type) has not been emphasized. We describe 4 men and 2 women (age, 40-79 years) with clinical and laboratory manifestations of WM and EMZL/MALT-type involving one or more sites: lung, pericardium/pleura, ocular adnexa, nasopharynx, minor salivary gland, glossopharyngeal fold, skin, and stomach. The following immunophenotypic patterns were observed: CD20+, 6; CD43+, 3; kappa light chain restriction, 5; and lambda light chain restriction, 1. All were negative for CD5, CD10, and cyclin D1 expression. A clonal paraproteinemia was present in each (IgM kappa, 4; IgM lambda, 1; biclonal IgM kappa/IgA kappa, 1). All 4 patients tested had elevated plasma viscosity; clinical HVS occurred in 3, and 2 required emergency plasmapheresis. These findings suggest that EMZL/MALT-type can cause WM and that the laboratory evaluation of EMZL/MALT-type should include serum protein electrophoresis/immunofixation, and plasma viscosity measurements and urine immunofixation in select cases. EMZL/MALT-type should be considered in the differential diagnosis in patients with clinicopathologic features of WM.

Adult↗

PubMed2001

The clinical significance of CD10 antigen expression in diffuse large B-cell lymphoma.

The clinical significance and prognostic value of CD10 in de novo diffuse large B-cell lymphoma (DLBCL) is largely unknown. We retrospectively studied 19 men and 9 women based on the following criteria: (1) DLBCL with no evidence of concomitant or antecedent follicular lymphoma; (2) available flow cytometric immunophenotyping data, including CD10 status; (3) older than 15 years; (4) specific exclusion of high-grade, Burkitt-like lymphoma; and (5) exclusion of primary cutaneous DLBCL. When available, clinical data at diagnosis, including components of the international prognostic index, were reviewed. Eleven cases were CD10+, and 17 were CD10-. There was no significant difference between the CD10+ and CD10- groups in age, sex, stage, performance status, extranodal involvement, or serum lactate dehydrogenase levels at diagnosis. However, in the 26 cases for which follow-up data were available, the CD10+ group displayed a shorter overall survival than the CD10- group (8 vs 30 months). Although the clinical findings at diagnosis are similar in CD10+ and CD10- DLBCL, CD10 expression is associated with shortened overall survival. Therefore, our data suggest CD10 expression may have prognostic importance in adults with de novo DLBCL.

Adult↗

PubMed2000

Anti-CD10 immunoperoxidase staining of paraffin-embedded acute leukemias: comparison with flow cytometric immunophenotyping.

CD10 is common in B-precursor acute lymphoblastic leukemia (ALL) but is rare in acute myeloid leukemia (AML). However, until recently, analysis for CD10 has generally required fresh or frozen tissue. 56C6 is a monoclonal antibody that is now commercially available for the detection of CD10 in routinely processed paraffin-embedded tissue. Immunoperoxidase stains for CD10 on paraffin-embedded bone marrow core biopsy specimens (B5-fixed, decalcified) and marrow aspirate clots (formalin-fixed) were compared with flow cytometric immunophenotyping for CD10 on fresh cell suspensions in 20 cases of AML and in 30 cases of ALL. CD10 detection by immunohistochemistry agreed with CD10 by flow cytometry in 98% (49 of 50) of acute leukemias. The results matched in 100% (20 of 20) of AML. Five percent (1 of 20) of AMLs expressed CD10. Two of the AMLs with monocytoid differentiation were interpreted as negative for CD10 by flow cytometry, although these had nonspecific dim immunofluorescence for multiple markers, including CD10, and these cases were negative by immunohistochemistry. CD10 detection by immunohistochemistry agreed with CD10 by flow cytometry in 97% (29 of 30) of ALL. Eighty-four percent (21 of 25) of B-precursor ALL and 40% (2/5) of T-lineage ALL expressed CD10 by immunohistochemistry. In 1 case of B-precursor ALL, CD10 was dimly positive in 24% of the blasts by flow cytometry but negative by immunohistochemistry. We conclude that immunohistochemical staining of paraffin-embedded tissue, either B5- or formalin-fixed, is an effective method for the detection of CD10 in acute leukemia. This technique is useful in distinguishing AML from ALL.

Acute Disease↗

PubMed2000

Mucosa-associated lymphoid tissue-type lymphomas occurring in post-transplantation patients.

Post-transplantation lymphoproliferative disorders (PTLDs) are usually Epstein-Barr virus (EBV)-associated B-cell lymphoproliferative disorders that vary in their morphologic spectrum. Extranodal marginal zone lymphomas of the mucosa-associated lymphoid tissue-type (MALT-type) have not been considered to be part of this spectrum. The authors encountered five such cases recently. The clinical, histopathologic, and immunophenotypic features are reported. There were three men and two women with a mean age of 51.2 years (range, 48-63 years). Two patients were cardiac transplant recipients, two patients were liver transplant recipients, and the remaining patient was a renal transplant patient. Sites of lymphoma were the stomach in three patients and the parotid gland in two patients. Mean time to the lymphoma was 84 months after transplantation. All patients had morphologic features of low-grade extranodal marginal zone lymphomas of the MALT-type, and Helicobacter pylori was present in all three gastric cases. All patients exhibited the B-cell immunophenotype and were negative for EBV by in situ hybridization. These lymphomas were treated with a variety of modalities, including reduction of immunosuppression, antibiotics, surgical resection, radiation therapy, and chemotherapy. At last follow-up, one patient had developed signet ring adenocarcinoma at 27 months but had no evidence of PTLD, one patient relapsed at 17 months but is alive with stable disease at 24 months, and the remaining patients were alive without disease at 11, 12, and 14 months. Extranodal low-grade MALT-type lymphomas can occur in the post-transplantation setting and generally develop years after transplant. As seen in immunocompetent patients, EBV appears to play no role in the pathogenesis of these lymphomas. These lymphomas appear to have more in common with MALT-type lymphomas in nonimmunocompromised patients than conventional PTLDs, although they occur in "at-risk" patients due to their immunosuppressive therapy. These lymphomas do not appear to be clinically aggressive. Recognition of MALT-type lymphomas in the post-transplantation setting as an indolent disease avoids unnecessary treatment.

Combined Modality Therapy↗

PubMed2000

Precursor B-lymphoblastic transformation of grade I follicle center lymphoma.

Part of the natural history of follicle center lymphoma (FCL) is transformation to a more aggressive neoplasm, almost always a diffuse large B-cell lymphoma. We describe a rare example of a precursor B-lymphoblastic transformation of grade I FCL occurring in a 45-year-old woman 12 years after initial presentation and 3 years after successful treatment for a diffuse large cell transformation. The lymphoblastic lymphoma shared the same immunoglobulin heavy chain gene rearrangement as the FCL as assessed by polymerase chain reaction amplification and direct sequencing, as well as identical kappa light chain gene rearrangements by Southern blot analysis. The immunoglobulin heavy chain variable gene sequences of both tumors showed numerous identical base substitutions compared with germline sequences and 3 additional mutations in the lymphoblastic lymphoma not present in the low-grade FCL. These results indicate origin of the lymphoblastic process from the mature follicle center B-cell clone, rather than divergent origin of the 2 tumors from a common immature B-cell precursor.

Adult↗

PubMed2000

Multiparameter immunohistochemical analysis of the cell cycle proteins cyclin D1, Ki-67, p21WAF1, p27KIP1, and p53 in mantle cell lymphoma.

BACKGROUND: Mantle cell lymphoma (MCL) is characterized by overexpression of cyclin D1, a G1 cyclin that participates in the control of cell cycle progression at the G1 to S phase transition. In addition to cyclin D1, other cell cycle regulatory molecules may be involved in the proliferation and progression of MCL. Mutation of p53, deletion of p16(INK4a), and loss of p21(WAF1) expression have been reported in some cases of blastoid MCL. OBJECTIVE: We sought to examine levels of expression of these proteins in typical and blastoid MCL and to determine whether differences were present between these subtypes of lymphomas. DESIGN: A retrospective series of typical and blastoid MCLs was evaluated for expression of the cell cycle-related proteins cyclin D1, p21(WAF1), p27(KIP1), Ki-67, and p53, as well as mitotic index. Paraffin-embedded archival tissues from 24 MCL specimens (17 typical, 7 blastoid) were immunostained with antibodies to p21(WAF1), p27(KIP1), p53, Ki-67, and cyclin D1. The percentage of positive cells for each specimen was estimated by counting 1500 cells under oil immersion microscopy. Levels of antigen expression were compared for the typical and blastoid MCLs. The mitotic index was estimated using twenty 100x oil immersion fields (OIFs) for each specimen. RESULTS: Cyclin D1 expression was seen in 22/24 specimens (92%). Blastoid MCLs were characterized by a significantly higher mean mitotic index (>20 mitoses/20 OIFs) and Ki-67 index (>45%) when compared with typical MCLs (P <.001 and P <.008, respectively; Fisher's exact test). High expression of p27(KIP1) (>25% staining) was seen more frequently in typical MCLs than in the blastoid variants (P =.03; Fisher's exact test). No significant differences were found between typical and blastoid MCLs for the expression of p21(WAF1) or p53. CONCLUSIONS: A significantly higher mitotic index and Ki-67 index were found in blastoid MCLs as compared with typical MCLs. Low p27(KIP1) expression was associated with the blastoid MCL variant. These findings confirm the high proliferative nature of blastoid MCL and suggest a role for p27(KIP1) in the negative regulation of the cell cycle in MCL.

Adult↗

PubMed1999

Leukemic phase of mantle cell lymphoma, blastoid variant.

Six patients with mantle cell lymphoma, blastoid variant, involving the blood are described. The circulating blast-like cells suggested the possibility of acute leukemias, chronic lymphoproliferative disorders or peripheralized lymphomas. The WBC counts ranged from 3,700 to 249,000/microL (3.7-249.0 x 10(9)/L) and the absolute lymphocyte counts from 1,000 to more than 200,000/microL (1.0 to > 200.0 x 10(9)/L). The peripheral blood smears showed a spectrum of cells, from small mature lymphocytes with irregular nuclei to medium-sized lymphocytes with blast-like chromatin. However, the morphologic features in a lymph node biopsy specimen and the immunophenotype confirmed a diagnosis of mantle cell lymphoma, blastoid variant. By flow cytometry the lymphoma cells expressed B-cell-associated antigens (CD19, CD20 and CD22), coexpressed CD5, lacked CD23, and expressed moderate intensity monoclonal surface immunoglobulin and CD20. Cytogenetic analysis showed the characteristic t(11;14) in 2 of 4 analyzed specimens. Mantle cell lymphoma, blastoid variant, is part of the differential diagnosis for blast-like cells.

Aged↗

PubMed1999

Precursor B lymphoblastic lymphoma presenting as lytic bone lesions.

Precursor B lymphoblastic lymphoma is an aggressive but potentially curable disease. This lymphoma most often manifests in the skin and lymph nodes and, less commonly, as lytic bone lesions. In the bone, this lymphoma must be differentiated from small round blue cell tumors, diffuse large B-cell lymphoma, and acute myelogenous leukemia. We describe the morphologic and immunophenotypic features in 4 patients, 2 children, 1 teenager, and 1 adult, who initially presented with bone pain and osteolytic lesions but without peripheral blood or iliac bone marrow involvement. Positive immunohistochemical staining of the neoplastic cells was observed for anti-CD10 (3/4), CD20 (3/4), CD34 (1/4), CD43 (4/4), CD45/CD45RB (2/4), CD79a (4/4), CD99 (MIC2) (2/4), and terminal deoxynucleotidyl transferase (4/4). CD3 was absent in all cases. Immunophenotyping these neoplasms is essential to establish the correct diagnosis of precursor B lymphoblastic lymphoma, and a panel of antibodies is required because of the immunophenotypic heterogeneity.

Adolescent↗

PubMed1998

Follicular large cell lymphoma with immunoblastic features in a child with Wiskott-Aldrich syndrome: an unusual immunodeficiency-related neoplasm not associated with Epstein-Barr virus.

Patients with Wiskott-Aldrich syndrome, a severe inherited immunodeficiency disorder, have a markedly increased risk of developing non-Hodgkin's lymphoma compared with the general population. These are uniformly diffuse aggressive B-cell neoplasms that resemble those seen in AIDS and the posttransplantation setting and also may be associated with Epstein-Barr virus. We report what to our knowledge is the first case of follicular lymphoma in a 14-year-old child with Wiskott-Aldrich syndrome. The neoplasm was composed predominantly of large cells with immunoblastic features, and it possessed light chain-restricted surface immunoglobulin, clonal immunoglobulin gene rearrangements, and a t(14;18). The tumor lacked Epstein-Barr virus sequences by in situ hybridization and Southern blot terminal repeat analysis. Interestingly, however, the tumor contained c-myc gene rearrangement.

Blotting, Southern↗

PubMed1998

Characterization of the lymphoid infiltrate in Hashimoto thyroiditis by immunohistochemistry and polymerase chain reaction for immunoglobulin heavy chain gene rearrangement.

A close relationship between Hashimoto thyroiditis (HT) and low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) has been shown. We used immunohistochemistry to study paraffin sections from 40 unselected cases of HT and scored cases according to the lymphoid infiltrate and presence of lymphoepithelial lesions (LELs). Clonality was assessed by kappa/lambda immunohistochemistry and polymerase chain reaction for immunoglobulin heavy chain gene rearrangement (IgH PCR). Histologic findings were compared with 2 cases of primary thyroid MALT-type lymphoma. In HT, the lymphoid infiltrate consisted predominantly of T cells in all cases; B cells, associated with germinal centers, did not have the appearance of marginal zone cells. All cases had identifiable T-cell LELs; immunohistochemistry confirmed inconspicuous, rare B-cell LELs in 13 of 40 cases. In all cases, plasma cells were polyclonal and IgH PCR showed a polyclonal pattern. Clinical follow-up was available for 34 patients. Lymphoma developed in none. In contrast, a B-cell predominant infiltrate of marginal zone cells was present in the MALT-type lymphomas that was not confined to germinal centers. Cytokeratin stains demonstrated severe loss of epithelial elements and destructive LELs. LELs are not, in isolation, a useful criterion for distinguishing low-grade MALT-type lymphoma of the thyroid from HT. Features associated with low-grade MALT-type lymphoma include a predominance of B cells, marked loss of epithelial elements, and destructive LELs composed of marginal zone B cells. Unselected cases of HT do not contain monoclones detectable by IgH PCR.

Adult↗

PubMed1998

Flow cytometric and immunohistochemical analysis of small lymphocytic lymphoma, mantle cell lymphoma, and plasmacytoid small lymphocytic lymphoma.

Small lymphocytic lymphoma (SLL), mantle cell lymphoma (MCL), and SLL plasmacytoid (SLLP) are malignant neoplasms of small B cells that may have overlapping cytologic features. Entities such as SLL with irregular nuclear contours may pose additional diagnostic difficulties. We investigated the utility of flow cytometric analysis and immunohistochemistry studies in distinguishing these disorders from each other. We reviewed 29 lymphomas and classified them as SLL (13 cases), MCL (8 cases), and SLLP (8 cases) based on histology and expression of cytoplasmic immunoglobulin light chain. Paraffin section immunohistochemistry was performed for CD5, CD20, CD23, CD43, CD45RA, CD45RO, and kappa and lambda light chains. Flow cytometric analysis was carried out by 2-color direct immunofluorescence for CD5, CD11c, CD19, CD20, CD22, CD23, FMC7, and kappa and lambda light chains. By immunohistochemistry, we found that the expression of CD23 in SLL discriminates between SLL and MCL and that the expression of CD23 and CD43 in SLL discriminates between SLL and SLLP. By flow cytometric analysis, we found that CD11c+ and dim fluorescence intensity of slg and dim fluorescence intensity of FMC7 in SLL distinguish SLL from MCL, and the expression of CD5+, CD23+ and dim fluorescence intensity of FMC7 in SLL distinguishes SLL from SLLP. We found no immunophenotypic difference between SLL and SLL with irregular nuclear contours.

Diagnosis, Differential↗

PubMed1998

Classification of primary gastric lymphomas according to histologic features.

Histologic features of low-grade gastric lymphomas of mucosa-associated lymphoid tissue (MALT) have been extensively described, and transformation to a large cell (high-grade) lymphoma can occur. We characterize high-grade gastric lymphoma histologically in an attempt to distinguish between MALT-type and non-MALT-type lesions. We studied a series of 60 gastric lymphomas and characterized them clinically, histopathologically, and immunophenotypically. Low-grade gastric lymphomas were classified according to established criteria. High-grade lymphomas were classified in three groups based on the presence or absence of a low-grade component and lymphoepithelial lesions (LELs): 1) high-grade MALT lymphomas appearing in low-grade MALT lymphomas (LG/HG MALT lymphoma); 2) large cell lymphoma with LELs composed of large cells (high-grade LELs) but without a low-grade component (HG MALT lymphoma); and 3) diffuse large cell lymphoma without a low-grade MALT lymphoma component or LELs (DLCL). Twenty-two lymphomas were classified as low-grade MALT lymphomas, 16 as LG/HG MALT lymphomas, 10 as HG MALT lymphomas, and 12 as DLCL. B-cell immunophenotype was confirmed in all 55 cases in which immunophenotyping was performed. Low-grade LELs were seen in all low-grade MALT lymphomas, and CD20(L26) expression confirmed B-cell phenotype in the LELs in 20 of 20 cases. Clinical follow-up was available for 56 patients (range, 1-264 months; mean, 57 months). Actuarial analysis of disease-specific survival and relapse-free survival showed that clinical stage was highly statistically significant (P < 0.0001), whereas histologic type and grade approached statistical significance. Multivariate analysis showed that clinical stage was the only significant factor in relapse-free and disease-specific survival.

Adolescent↗

PubMed1998

Evaluation of CD23 expression in paraffin-embedded gastric lymphomas of mucosa-associated lymphoid tissue.

The CD23 antigen is expressed in a normal subset of B lymphocytes and in some non-Hodgkin's lymphomas. Reactivity for anti-CD23 (BU38) is present in paraffin-embedded tissue in the large majority of nodal small lymphocytic lymphomas, as well as in follicular center cell lymphomas. Most studies of gastric lymphomas of mucosa-associated lymphoid tissue (MALT) reported a lack of CD23, but these studies were performed on frozen tissue. We evaluated CD23 staining in paraffin-embedded tissue in a large series of gastric MALT lymphomas, as well as in cases of chronic gastritis. We assayed 49 well-characterized gastric lymphomas (9 high-grade non-MALT and 40 MALT [20 low grade, 13 mixed low and high grade, and 7 high grade]). High-grade MALT lymphomas without a low-grade component were distinguished from high-grade non-MALT lymphomas by the presence of lymphoepithelial lesions composed of large cells. In addition, we studies nine cases of chronic gastritis containing B-cell aggregates. We used anti-CD23 (BU38) in formalin-fixed, paraffin-embedded tissue. All of our low-grade gastric MALT lymphomas lacked CD23 immunoreactivity. One of the 13 mixed low-grade and high-grade lesions showed CD23 expression in the high-grade component. All of the high-grade MALT and high-grade non-MALT lesions lacked CD23. All of the nine cases of chronic gastritis lacked CD23. CD23 highlighted residual follicular dendritic cells and gastric epithelium. We concluded that gastric MALT lymphomas lacked CD23 (BU38) in paraffin-embedded tissue, with rare exceptions. This lack of CD23 expression might represent a useful feature in small or partially crushed biopsy specimens, particularly in the differential diagnosis with follicular small cleaved cell lymphoma presenting in the gastrointestinal tract.

Chronic Disease↗

PubMed1997

Detection of hepatitis C by RT-PCR in formalin-fixed paraffin-embedded tissue from liver transplant patients.

The histopathologic alterations of hepatitis C virus (HCV) infection of the liver overlap with those of other diseases, making interpretation of liver biopsy specimens in some cases insufficient to render a diagnosis. Although HCV infection can be confirmed by detection of circulating anti-HCV antibodies, immunocompromised liver transplant recipients are often unable to mount an immunologic response to the virus, resulting in false-negative serologic testing. We describe the comparison of reverse transcription-polymerase chain reaction (RT-PCR) with histopathology, serology, and immunohistochemistry for the diagnosis of HCV. Sixty-three formalin-fixed, paraffin-embedded tissue samples (40 needle biopsy specimens and 23 native liver resection specimens) from 35 transplant patients were analyzed by use of a novel method of RNA extraction followed by nested PCR for HCV as well as albumin mRNA as an internal control. HCV was detected by RT-PCR in 50 of 51 (98%) paraffin sections of liver from transplant patients with circulating anti-HCV antibodies, 15 of which lacked characteristic histologic features of HCV infection. Overall, there were no false-negative results in 36 needle biopsy specimens from patients with hepatitis C infection, but three negative results were seen in end-stage cirrhotic native livers resected from HCV-infected patients. No false-positive test results were seen among 21 negative controls (10 liver samples from immunocompetent patients with abnormalities unrelated to hepatitis C and 11 liver biopsies from immunocompetent patients without histologic evidence of liver disease). In comparison, immunohistochemistry using antibody TORDJI-22 was positive for HCV in only 15 of 32 (47%) needle biopsies positive by RT-PCR. Our results indicate that RT-PCR is a more sensitive and specific method of detecting hepatitis C in routinely processed paraffin sections of formalin-fixed liver biopsy specimens than histopathologic examination or immunohistochemistry.

Formaldehyde↗

PubMed1997

The t(2;5)-associated p80 NPM/ALK fusion protein in nodal and cutaneous CD30+ lymphoproliferative disorders.

A high percentage of extracutaneous CD30+ anaplastic large cell lymphomas (nodal ALCL) carry a specific chromosomal translocation, t(2;5) (p23;q35), that results in abnormal expression of p80 NPM/ALK chimeric protein (p80). The protein p80 may be detected by immunohistochemistry using polyclonal (anti-p80) or monoclonal (ALK1) antibody directed against the ALK epitope. Although nodal ALCL, primary cutaneous ALCL, and lymphomatoid papulosis type A (lyp A) have similar histologic and immunohistochemical features, the expression of p80 in these cutaneous lesions has not been extensively studied. We immunostained tissues from 10 nodal ALCL, 8 primary cutaneous ALCL, 24 lyp A, and positive and negative controls using polyclonal rabbit anti-p80 and the avidin-biotin-peroxidase labeling method. Reactivity was determined by comparing staining intensity to positive controls [4 nodal ALCL with t(2;5)] and negative controls (21 non-ALCL lymphomas). Only cutaneous lesions staining positively with anti-p80 were further studied with the monoclonal antibody ALK1 and reverse transcription polymerase chain reaction (RT-PCR) for p80 messenger RNA. All positive controls (4/4), but none of the negative controls (0/21) nor lyp A (0/24), were immunoreactive for anti-p80. Sixty percent (6/10) of nodal ALCL and a single case (12%) of primary cutaneous ALCL were immunoreactive for anti-p80. In this exceptional cutaneous lesion, although we did not find NPM/ALK by RT-PCR, we detected strong expression of ALK using ALK1. We conclude that t(2;5) is rarely involved in the pathogenesis of cutaneous CD30+ lymphoproliferative disorders.

Anaplastic Lymphoma Kinase↗

PubMed1997

Stromal tumors of the jejunum and ileum.

Gastrointestinal stromal tumors (GISTs), as currently defined, are mesenchymal tumors of the gastrointestinal tract composed of spindled and/or epithelioid stromal cells that are neither mature Schwann cells nor smooth muscle cells. Many studies have lumped GISTs from all gut sites, when in fact these tumors differ histologically by location. In this study, we evaluated a set of parameters by both univariate and multivariate analysis to determine which parameters correlated with metastases in 36 GISTs from the jejunum and ileum, exclusively. The parameters included organoid architecture, cellularity, mitotic counts, epithelioid cell shape, mucosal invasion, tumor size, skeinoid fibers, nuclear pleomorphism, ischemic necrosis, immunohistochemical differentiation, and proliferating cell nuclear antigen labeling. We evaluated these retrospectively without knowledge as to the metastatic outcome of the tumors. By univariate analysis, dense cellularity, mitotic counts, epithelioid cell shape, mucosal invasion, and size were statistically significant correlates with metastases. By multivariate analysis, only dense cellularity and mitotic counts were independent correlates with metastases. Whether these features are useful predictors of behavior remains to be tested.

Adult↗