Breast Lesions Involving Subcutaneous Fat Layer : Sonographic Findings for Differentiation between Benign and Malignant Lesions.

Yoon,  In Sook; Chung,  Soo Young; Yang,  Ik; Park,  Hai Jung; Lee,  Yul; Ko,  Mi Gyung

Journal of Korean Society of Medical Ultrasound 1997;16(1): 71-77.

In Sook Yoon, Soo Young Chung, Ik Yang, Hai Jung Park, Yul Lee, Mi Gyung Ko

Department of Radiology, College of Medicine, Hallym University Hospital, Korea.

Published online: January 1, 2001.

ABSTRACT

PURPOSE: To evaluate the usefulness of ultrasound for differential diagnosis between benign and malignant breast lesions involving subcutaneous fat layer. MATERIALS & METHODS: We retrospectively evaluated the sonographic findings in differential diagnosis of 38 patients of breast lesions involving subcutaneous fat layer. Benign lesions were 17 cases (hemangioma 2, hamartoma 1, abscess 6, hematoma 4, tuberculosis 2, superficial phlebitis 2) and malignant lesions were 21 cases (inflitrating ductal carcinoma 16, inflammatory breast carcinoma 3, recurred carcinoma 2). The results were evaluated in regard to the homogeneity of lesions, the presence of mass, the patterns of subcutaneous thickening, the maximal thickness of subcutaneous fat layer, the retraction and discontinuity of subcutaneous fat layer and the extent of the lesions. As a control group, 20 normal breasts were evaluated the thickeness of subcutaneous fat layer according to the Wolfe's parenchymal patterns and central and peripheral region by US. RESULTS: The mean thickeness of subcutaneous fat layer in normal control group (n=20) by US was 9.6 mm. The peripheral region of the P1 parenchymal pattern showed the thickest subcutaneous fat layer in control group. The subcutaneous layer in malignant group (14.1 mm) was thicker than that of control (9.6 mm) and benign group (10.2 mm). The benign lesions showed homogeneity in echotexture, focal thickening of subcutaneous fat layer, and involvement of only subcutaneous fat layer. In contrast, the malignant lesions showed inhomogeneous echotexture, diffuse subcutaneous thickening, and involvement of subcutaneous and parenchymal layer. The malignant lesions showed the higher frequency of the retraction and discontinuity of the subcutaneous fat layer than benign lesions. CONCLUSION: The breast ultrasound is a very useful method in differential diagnosis of benign and malignant breast lesions involving the subcutaneous fat layer.

Keywords: Breast; US