Localized Subcutaneous Insulin-Derived Amyloidosis Excised after Evaluation Using Ultrasonography in a Patient with Type 2 Diabetes Mellitus

Figure 3

Comparison of preoperative abdominal ultrasound findings (a) and Congo red-stained histopathological findings (b). The high magnification figures (×200) of Congo red staining (c) and its green birefringence (d). (a) On ultrasonography, the subcutaneous mass is shown as a somewhat heterogeneous, hypoechoic area under the dermis. (b) Congo red-stained section of the mass shows diffuse, irregular, lumpy amyloid deposition (indicated by broken-lined ovals). When the material was stained with Congo red staining (c) and seen with polarized light, we saw green birefringence (d), diagnostic of amyloid.