Stereologic study of splenic tissue compartments from traumatically injured and cancer patients

Carefully age-matched groups of patients, surgically treated for either traumatic injury (n = 5; mean = 71.2 years) or for early stage carcinoma (n = 5; mean = 74.2 years), were used to investigate all the splenic tissue compartments applying model-based stereology. The point-counting method was utilized to study the volume densities of following tissue compartments: red pulp, perifollicular zone, white pulp (this compartment was divided into two subcompartments: follicles and periarteriolar lymphatic sheath), marginal zone and connective tissue. The following stereologic parameters of lymphoid follicles were determined: areal numerical density (the number of follicles per mm2 of tissue section), the numerical density (number of follicles per mm3 of tissue), and the mean follicle diameter. The identity of tissue compartments was verified using immunohistochemical staining for B- and T- lymphocytes. Significantly increased volume densities of perifollicular zone and periarteriolar lymphatic sheath were registered in patients treated for traumatic spleen injury. On the other hand, the significantly increased number of lymphoid follicles per mm2 and per mm3 of splenic tissue were registered in the group of cancer patients. The differences observed, whether attributable to the immune stimulation of the ruptured spleen or the alterations of the immune system due to malignant disease, suggest that this issue deserves further attention.