[Pathology of liver lesions in malignant non-Hodgkin lymphomas (author's transl)]

The Kiel classification of lymphomas based on cytological criteria can be applied to tumor cell types found in liver infiltrates as well. Lymphomas with low degree of malignancy are delineated distinctly against the normal parenchyma; the borderline is slightly blurred only in the centroblastic-centrocytic subtype. Generally, the portal fields in these cases are round-shaped, expanded, and filled with lymphoid cells. Lymphomas with a high degree of malignancy are characterized on the contrary by portal fields with very irregular borderlines; in some cases there is a certain similarity to piece meal necrosis. There is an increased incidence of mitoses in the malignant tissue. Bile ducts are often disrupted. Hair cell leukemia can be differentiated in paraffin sections too, if tartrate-resistent acid phosphotase is present.