Actual volume estimation of the paracortex in lymph nodes by morphometry. Significance of centrally placed sections

Variation of paracortical size in lymph nodes has been demonstrated to be an important indicator of paracortical activation under chronic antigenic stimulation. This introduces a stereologic problem that can be solved by the analysis of serial sections. However in practical applications, a such procedure is too time consuming. Evidence is presented here that data from centrally placed, single sections in mice and guinea pigs may serve as a fairly good parameter for paracortical volume fractions when groups of lymph nodes are analyzed. However in predicting individual volume fractions, there is considerable risk of serious deviation from actual values.