RASA1 and metastatic malignant neoplasm in the lymph nodes: Positive RASA1 staining was observed in 44.1% (15/34) of Clark's nevi, 33.3% (21/63) of primaries, 11.4% (4/35) of lymph node metastases, and 3.4% (1/29) of distant metastases (Figure 2).