Relationship of the lymphoplasmacytic infiltration of skin tumors to tumor ulceration

The lymphoplasmacytic infiltrates of 400 bening, borderline, and malignant skin tumors were assessed by light microscopy to determine the relationship between the presence of tumor ulceration and the histologic character of the infiltrate. Squamous cell carcinoma had the highest overall number of infiltrating lymphoplasmacytic cells, while seborrheic keratoses had the lowest. Plasma cells in the infiltrates were related significantly to tumor ulceration (P < .001). This suggests that the plasma cell infiltrates may be more related to tumor ulceration than to a tumorspecific response in these carcinomas. Small lymppocytes were most evident adjacent to areas of irregularity in the peripheral palisade or of squamous differentiation of the basal cell carciomas. This suggests that the presence of small lymphocytes, not plasma cells, is a response by the immunocompetent host to areas of tumor invasion.