Biomedical subjects

Zach Liu

Publications and source records attributed to Zach Liu.

6 recordsLinked to original sources

PubMed2004

Flow cytometry in the diagnosis of mediastinal tumors with emphasis on differentiating thymocytes from precursor T-lymphoblastic lymphoma/leukemia.

Flow cytometry (FC) has become the routine technique in the evaluation of hematopoietic neoplasms. Since the anterior mediastinum is a frequent site of involvement by both primary and secondary lymphoma/leukemia, flow cytometry plays an important role in the evaluation of mediastinal masses. The present study reviews 100 flow cytometry cases from patients presenting with mediastinal lesions. In 5 cases (5%) flow cytometry was not diagnostic due to either insufficient cell yield or low viability. In the remaining cases (95/100) cell suspensions were adequate for flow cytometry evaluation. Results showed that in 31/32 (96.8%), 2/3 (66.7%), 7/9 (77.8%), 7/8 (87.5%) and 11/11 (100%) cases of B-cell lymphoma, T-cell lymphoma, carcinoma, T-ALL/LBL and thymoma/thymic hyperplasia, respectively, the diagnosis could be reached by flow cytometry alone. Excluding HL, the general sensitivity of FC in diagnosing mediastinal tumors was approximately 92%. Among the 100 cases, flow cytometry gave non-informative results in 3 cases of diffuse large B-cell lymphoma, 1 case of peripheral T-cell lymphoma, and 3 cases of carcinoma. No false positive results were encountered. The phenotypic pattern, especially surface CD3 expression versus forward scatter, reliably discriminated between immature thymocytes from thymoma/thymic hyperplasia from T-ALL/LBL. Flow methodology has the advantage of rapid turn-around time as well as high sensitivity, enabling patients with large anterior mediastinal masses and/or superior vena cava syndrome to begin treatment as promptly as possible. In experienced hands, flow cytometry plays a valuable and complementary role to histology and immunohistochemistry in diagnosing mediastinal tumors.

Adolescent↗

PubMed2003

B-cell lymphomas with coexpression of CD5 and CD10.

Coexpression of CD5 and CD10 is highly unusual in B-cell lymphomas and may pose a diagnostic challenge. We report 42 cases of B-cell lymphoma with simultaneous expression of CD5 and CD10. They made up approximately 0.4% of all B-cell lymphomas seen during the study period and included the following cases: large B-cell lymphoma (LBCL), 14 (33%); follicular lymphoma (FL), 10 (24%); mantle cell lymphoma (MCL), 9 (21%); chronic lymphocytic leukemia, 4 (10%); acute precursor B-cell lymphoblastic leukemia/lymphoma, 2 (5%); and other low-grade B-cell lymphomas, 3 (7%). All MCLs had overexpression of bcl-1 or the t(11;14) and were CD43+. All FLs had typical histomorphologic features and were bcl-2+ and bcl-6+ but CD43-. Of 14 LBCLs, 5 were histologically high-grade. Six (43%) of 14 patients with LBCL died within 10 months of diagnosis of CD5+CD10+ lymphoma (median survival, 4 months), including all 3 patients with stage IV disease and 2 of 5 with histologically high-grade lymphoma. Our findings indicate that coexpression of CD5 and CD10 is rare but occurs in diverse subtypes of B-cell lymphoma. Investigation of bcl-1, bcl-6, and CD43 and morphologic evaluation may resolve the potential confusion in diagnosis and lead to the recognition of the correct lymphoma subtype.

Adult↗

PubMed2003

Down-regulation of pan-T-cell antigens, particularly CD7, in acute infectious mononucleosis.

Multiparameter flow cytometric analysis was performed on the peripheral blood samples from 25 patients with acute infectious mononucleosis. Phenotypic results were matched with those for patients without viral symptomatology. Samples from all patients with infectious mononucleosis exhibited an activated (HLA-DR+, CD38+) CD8+ cytotoxic-suppressor T-cell population with aberrant down-regulation of CD7, and samples from 2 (8%) of 25 patients also showed down-regulation of CD5. The CD8+ cells also were slightly larger than normal T cells by forward scatter characteristics. None of the control samples showed down-regulation of either antigen. Aberrant pan-T-cell antigenic expression is a criterion in the immunophenotypic diagnosis of T-cell lymphoproliferative disorders. Acute Epstein-Barr virus infection should be considered in the differential diagnosis when down-regulation of CD7 is present, especially in conjunction with an activated CD8+ T-cell population.

Acute Disease↗

PubMed2003

The potential role of flow cytometry in the diagnosis of small cell carcinoma.

CONTEXT: Virtually no information exists in the medical literature on the immunophenotyping of small cell carcinoma by flow cytometry. CD56, or neural cell adhesion molecule, is widely expressed by small cell carcinoma and easily measured by flow cytometry. OBJECTIVE: To determine the potential usefulness of flow cytometry in the diagnosis of small cell carcinoma. DESIGN AND SETTING: Retrospective data and archival material on 27 patients were obtained from community hospitals. Specimens (needle aspirations and tissue biopsies) from all patients demonstrated cytomorphologic and flow cytometric features consistent with small cell carcinoma. All measurements were performed at a large reference laboratory. Routine 3- and 4-color flow cytometry using a lymphoma antibody panel, including anti-CD56, was performed. Anti-cytokeratin antibody was also used in the last 12 cases. Immunohistochemical staining with a panel of conventional markers for neuroendocrine neoplasms was performed on available tissue for purposes of confirmation of small cell carcinoma. PATIENTS: Twenty-seven patients whose tissue specimens showed a clearly defined population of CD45-CD56+ cells by flow cytometry and cytomorphologic features consistent with small cell carcinoma. INTERVENTIONS: Needle aspiration (n = 3) and tissue biopsy (n = 24) from a variety of sites. RESULTS: CD56 positivity by flow cytometry was 100 to 1000 times that of the matched isotype control in 25 cases and 10 to 100 times that of the control in 2 cases. Cytokeratin positivity by flow cytometry was found in 12 of 12 cases. Immunohistochemical staining showed positivity for at least 1 cytokeratin and 1 or more neuroendocrine markers in 26 of 27 cases and confirmed the diagnosis of small cell carcinoma. CONCLUSIONS: Routine flow cytometry can identify a neuroendocrine phenotype that shows a strong correlation with confirmatory immunohistochemical markers in cases exhibiting cytomorphologic features of small cell carcinoma. Flow cytometry appears to complement and may possibly be a satisfactory alternative to immunohistochemical staining when small cell carcinoma is suspected.

Biomarkers, Tumor↗

PubMed2003

CD30-positive T-cell lymphomas co-expressing CD15: an immunohistochemical analysis.

The characteristic histologic features and immunophenotype are usually diagnostic and allow distinguishing CD30 positive T-cell lymphoma (including anaplastic large cell lymphoma) from classical Hodgkin's lymphoma. The latter differs by expression of CD15 and lack of CD45, pan-T antigens and ALK expression. We report nine cases of large cell hematopoietic neoplasms in which the neoplastic cells co-expressed CD30 and CD15, and had immunophenotypic and morphologic features of T-cell lymphoproliferative process. The average age of the CD15-positive group was 61.9 years; 6 cases occurred in men and 3 in women. The tumors were located in lymph nodes in 8 cases, and in liver in 1 case. Two cases expressed ALK protein. There were no statistically significant differences in phenotypic parameters between the CD15-positive and CD15-negative neoplasms (p>0.05). However, the CD15-positive group appeared to show a minor trend toward less positivity for EMA (44% versus 72%), ALK protein (22% versus 51%), and CD45RO (33.3% versus 83.3%, p=0.07), when compared to the typical CD15-negative neoplasms. In summary, although the co-expression of CD30 and CD15 is typical for classical HL, it may be also present in a subset of peripheral T-cell neoplasms including ALK-positive anaplastic large cell lymphoma. Combined and sensible use of morphology and a broad immunophenotypic panel in cases with limited material and/or those with overlapping histologic patterns will best discriminate between HL and ALCL. It is incumbent upon the pathologist to distinguish between these two clinicopathologic entities, since treatment options and clinical outcomes differ.

Adolescent↗

PubMed2002

CD5- mantle cell lymphoma.

Mantle cell lymphoma (MCL) typically expresses B-cell antigens and CD5 and overexpresses bcl-1 protein. However, unusual cases of bcl-1+ and CD5-MCL have been observed, posing a practical challenge for correct diagnosis and management. We identified 25 cases (48 samples) of bcl-1+ and CD5- lymphoma. CD5 expression was assessed by flow cytometric analysis alone (1 case), immunohistochemical analysis alone (17 cases), or dual flow cytometric/immunohistochemical methods (7 cases). The morphologic features were consistent with MCL with centrocytic cytomorphology in 20 cases and blastic variant in 5 cases. The t(11;14) was confirmed in 8 of 11 cases by fluorescence in situ hybridization of paraffin-embedded tissue. Cytogenetic analysis revealed the t(11;14) within a complex karyotype in 2 additional cases. These data show that MCL may lack CD5 expression. Evaluation of bcl-1 expression by immunohistochemical analysis or molecular genetics may be indicated if MCL is suspected clinically or morphologically despite a lack of CD5 expression.

Aged↗