Histological classification of gastric adenocarcinoma for epidemiological research: concordance between pathologists.

Epidemiology of gastric adenocarcinoma suggests that intestinal-type and diffuse-type cancers develop through distinct causal pathways. To examine the differences in risk factors and molecular changes between the histological types, reliable data on histological typing are essential. We evaluated the concordance between two pathologists in assessment of 95 gastric adenocarcinomas for Laurén classification and tumor grade. Two pathologists, each blinded to the other's assessment, reviewed H&E-stained slides of gastric tumor. The responses of the two pathologists for histological type were considered as concordant if they fell on one of the three categories (intestinal type, diffuse type, or other). Tumor grade was classified into three categories (well, moderately, or poorly differentiated). The pathologists agreed on the classification of histological type for 71 of 92 (77%) tumors. Kappa coefficient was 0.59 (95% confidence interval, 0.44-0.73). Concordance for tumor grade was 87%, with a kappa coefficient of 0.72 (95% confidence interval, 0.57-0.87). Both observed concordance and kappa coefficient for histological type and tumor grade were similar across three calendar periods of study. Interobserver agreement was virtually identical between tumors with biopsy specimens only and those with surgical specimens. Although the level of disagreement for histological type observed in this study is comparable with that in other studies, the resulting misclassification would lead to the reduction in observed differences in prevalence and odds ratio estimates between two histological types.

Sinonasal mucosa-associated lymphoid tissue lymphoma.

Mucosa-associated lymphoid tissue (MALT) is a specialized form of lymphoid tissue that may be acquired at sites in response to chronic inflammation. Most low-grade, B-cell, non-Hodgkin lymphomas that occur at extranodal sites derive from acquired MALT. Confusing and overlapping terms have been used to describe these lymphomas, but immunohistochemical advances now allow more precise subtyping. Our review of the literature yielded only 2 previous reports of sinonasal MALT-derived lymphoma, and we report an additional case in a patient with a history of chronic sinusitis. Current developmental theories of MALT-derived lymphomas are discussed. In addition, we review the clinical, histologic, and immunophenotypic features of MALT-derived lymphomas.

Efficacy and cost-effectiveness of multihole fine-needle aspiration of head and neck masses.

To determine whether the specimen from fine-needle aspiration (FNA) biopsy of head and neck masses has greater diagnostic accuracy when using multihole needles than when using conventional, single-hole needles, we did a prospective, randomized, single-blinded study comparing diagnoses obtained using both types of needles in FNA biopsies of head and neck masses. Eighty-eight patients served as their own controls and had 91 FNA biopsies with both multihole and single-hole, 22-gauge needles. Order of biopsy was randomized and was unknown to the cytopathologist. No statistically significant differences were noted in quantity of specimen material obtained, quality of fixation, or diagnostic value between the multihole and conventional needle. We found no advantage in using the more costly multihole needle in FNA biopsy of head and neck masses.