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Aims: Tissue microarrays offer an efficient way of examining a large number of tumour cases on a single glass slide. A major concern, however, is tumour heterogeneity. Also, the use of tissue microarrays in biopsy material is unexplored. The purpose of the present study was to assess the possibility and validity of arraying three 0.6-mm cores per case in endoscopic gastric cancer biopsies for immunophenotyping. Methods and results: Thirty-eight cases were studied with immunohistochemical staining for p53, CD44v6 and vascular endothelial growth factor. Full tissue sections were compared with triple core-tissue microarrays. Thirty-six cases contained three cores with tumour, one case contained two cores with tumour and one case contained only a single core with viable tumour and was excluded. Three further cores had been lost from three separate cases on the sections for immunohistochemistry. κ values for whole-sections versus tissue microarrays ranged between 0.77 and 0.94. p53 immunohistochemical staining (interpretation as + or –) yielded the best result with only 1/37 mismatches, whereas CD44v6 (graded both for intensity and extent) showed 3/37 mismatches. The small depth of tissue in cores from biopsies necessitates all cores being arrayed flush with the face of the recipient wax block for maximizing the number of sections available. Compared with the first section over 30 additional 4-µm sections were available before the first case (with one core left) had to be excluded and 80 sections before half the tissue cores were lost. Conclusions: It is impracticable to array more than 120–150 cores per block. Tissue microarray with three cores per case is feasible and valid for studying biopsy material. [ABSTRACT FROM AUTHOR]

Perea G, Altés A, Bellido M, Aventín A, Bordes R, Ayats R, Remacha A F, Espinosa I, Briones J, Sierra J & Nomdedéu J F (2004) Histopathology 45, 268–274 Clinical utility of bone marrow flow cytometry in B-cell non-Hodgkin lymphomas (B-NHL) : To determine the efficacy of flow cytometry (FC) in the assessment of bone marrow (BM) in B-cell non-Hodgkin lymphoma (B-NHL). FC is a common practice, but is far from being validated. : Morphological analysis and FC immunophenotyping were perfomed on 421 samples. T-cell lymphomas, Hodgkin's disease, chronic lymphocytic leukaemia and hairy cell leukaemia were not included in the study. Clonality was assessed by the standard κ/λ/CD19 test. Aberrant immunophenotypes present in the B-cell subpopulation were also investigated. A double-step procedure was employed in all cases to increase the sensitivity of the FC procedure. Of 380 evaluable samples, 188 corresponded to follicular lymphoma (FL), 58 to diffuse large B-cell lymphoma (DLBCL), 57 to mantle cell lymphoma (MCL), seven to Burkitt's lymphoma and the remaining 70 samples to other low-grade lymphomas. Morphological marrow infiltration was found in 148 cases, and flow immunophenotyping identified 138 cases with BM involvement. A concordance between the two methods was detected in 298 cases (79%). There was a discordance in 82 cases (21%): morphology positive/FC negative in 46 cases and morphology negative/FC positive in 36 (61% of all cases with discordance were from FL). There was no difference in outcome when patients with discordances were compared with patients without discordances. : Most samples showed concordance between morphological and FC results. FC identified BM involvement in the absence of morphological infiltration. Morphology/FC discordance seems to have no influence on the outcome of FL patients. [ABSTRACT FROM AUTHOR]