Song Hanqing, Cheng Yin, Wang Xiuqin, Hong Xinyi, Guo Ze, Li Hui, Li Li, Wang Peiguang
Department of Dermatology, The First Affiliated Hospital, Anhui Medical University, Hefei, Anhui, China.
Institute of Dermatology, Anhui Medical University, Hefei, Anhui, China.
J Dermatol. 2025 Feb;52(2):281-290. doi: 10.1111/1346-8138.17562. Epub 2024 Dec 12.
Primary cutaneous amyloidosis (PCA) is a chronic pruritic skin disease. The apple-green birefringence of Congo red-stained amyloid under a polarized light microscope (CR-PLM) remains the gold standard in the diagnosis of PCA. However, there are some limitations to this approach. In this study, eighty-two paraffin-embedded biopsy skin samples were collected from patients with a clinical diagnosis of PCA. The sections were respectively stained with hematoxylin-eosin (HE), crystal violet (CV), and Congo red (CR) and observed under a light microscope. CR-stained sections were also observed under a polarized light microscope (CR-PLM) or an ultraviolet (UV)-emitted fluorescence microscope (CR-UFM). Further, 35 cases clinically diagnosed with psoriasis, lichen planus, and prurigo nodularis were selected as the negative control group. The positive rate of amyloid protein detected by CR-UFM (81.71%) was significantly higher than that detected by CR-PLM (70.73%, p = 0.004), CR staining (56.10%, p < 0.001), CV staining (30.49%, p < 0.001), or HE staining (28.05%, p < 0.001). In the control group, 34 (97.14%) cases were negative for amyloid deposits in CR staining, CR-PLM, and CR-UFM sections. The relative number of positive dermal papillae observed by CR-UFM (0.35 ± 0.27) was much more than that observed by CR-PLM (0.15 ± 0.17, p<0.001), CR staining (0.12 ± 0.16, p < 0.001), CV staining (0.07 ± 0.12, p < 0.001), or HE staining (0.05 ± 0.12, p < 0.001). The intensity of fluorescence by CR-UFM was significantly greater than that of the appl-green birefringence by CR-PLM (p < 0.001). Moreover, the amyloid was easily distinguished from the surrounding tissues using the CR-UFM method. In conclusion, the CR-UFM method was superior to CR-PLM, CR staining, CV staining, and HE staining in diagnosing PCA.
原发性皮肤淀粉样变（PCA）是一种慢性瘙痒性皮肤病。偏振光显微镜下刚果红染色淀粉样蛋白呈现的苹果绿双折射（CR-PLM）仍是PCA诊断的金标准。然而，这种方法存在一些局限性。在本研究中，从临床诊断为PCA的患者中收集了82份石蜡包埋的皮肤活检样本。切片分别用苏木精-伊红（HE）、结晶紫（CV）和刚果红（CR）染色，并在光学显微镜下观察。CR染色切片还在偏振光显微镜（CR-PLM）或紫外（UV）发射荧光显微镜（CR-UFM）下观察。此外，选择35例临床诊断为银屑病、扁平苔藓和结节性痒疹的病例作为阴性对照组。CR-UFM检测淀粉样蛋白的阳性率（81.71%）显著高于CR-PLM（70.73%，p = 0.004）、CR染色（56.10%，p < 0.001）、CV染色（30.49%，p < 0.001）或HE染色（28.05%，p < 0.001）。在对照组中，34例（97.14%）在CR染色、CR-PLM和CR-UFM切片中淀粉样蛋白沉积为阴性。CR-UFM观察到的真皮乳头阳性相对数量（0.35 ± 0.27）远多于CR-PLM（0.15 ± 0.17，p<0.001）、CR染色（0.12 ± 0.16，p < 0.001）、CV染色（0.07 ± 0.12，p < 0.001）或HE染色（0.05 ± 0.12，p < 0.001）。CR-UFM的荧光强度显著大于CR-PLM的苹果绿双折射强度（p < 0.001）。此外，使用CR-UFM方法很容易将淀粉样蛋白与周围组织区分开来。总之，在诊断PCA方面，CR-UFM方法优于CR-PLM、CR染色、CV染色和HE染色。
