Pathological changes of the abdomen showed hyperkeratosis and mild irregular acanthosis, the granular layer was thin and melanophage and perivascular lymphocytic infiltration in upper dermis. 腹部皮损组织病理学检查示,表皮角化过度,颗粒层变薄,棘层不规则增厚,真皮浅层散在噬色素细胞,血管周围有淋巴细胞浸润。