RATIONALE AND OBJECTIVES: The authors performed this study to determine whether, on the basis of the vascular profile, low-grade siderotic dysplastic nodules are premalignant lesions. MATERIALS AND METHODS: The authors used a monoclonal antibody specific for smooth muscle actin to stain 18 siderotic low-grade dysplastic nodules (mean size, 0.7 cm) from nine patients. Two pathologists counted the number of unpaired arteries per high-power field in siderotic dysplastic nodules and background siderotic regenerative nodules by using two techniques (conventional and hot spot). RESULTS: The number of unpaired arteries seen with the conventional counting technique in low-grade siderotic dysplastic nodules (range, 1-14; mean, 3.8) was significantly greater (P = .004) than that seen in background siderotic regenerative nodules (range, 0-3; mean, 1.2). Similarly, the number of unpaired arteries seen with the hot spot technique in low-grade siderotic dysplastic nodules (range, 0-14; mean, 5.2) was significantly greater (P = .005) than that seen in background siderotic regenerative nodules (range, 0-6; mean, 1.9). CONCLUSION: On the basis of the vascular profile, low-grade siderotic dysplastic nodules should be considered premalignant lesions. Further research is needed to help differentiate these lesions from siderotic regenerative nodules with magnetic resonance imaging.
RATIONALE AND OBJECTIVES: The authors performed this study to determine whether, on the basis of the vascular profile, low-grade siderotic dysplastic nodules are premalignant lesions. MATERIALS AND METHODS: The authors used a monoclonal antibody specific for smooth muscle actin to stain 18 siderotic low-grade dysplastic nodules (mean size, 0.7 cm) from nine patients. Two pathologists counted the number of unpaired arteries per high-power field in siderotic dysplastic nodules and background siderotic regenerative nodules by using two techniques (conventional and hot spot). RESULTS: The number of unpaired arteries seen with the conventional counting technique in low-grade siderotic dysplastic nodules (range, 1-14; mean, 3.8) was significantly greater (P = .004) than that seen in background siderotic regenerative nodules (range, 0-3; mean, 1.2). Similarly, the number of unpaired arteries seen with the hot spot technique in low-grade siderotic dysplastic nodules (range, 0-14; mean, 5.2) was significantly greater (P = .005) than that seen in background siderotic regenerative nodules (range, 0-6; mean, 1.9). CONCLUSION: On the basis of the vascular profile, low-grade siderotic dysplastic nodules should be considered premalignant lesions. Further research is needed to help differentiate these lesions from siderotic regenerative nodules with magnetic resonance imaging.