Vijaya B, Dalal Bibhas Saha, Manjunath G V
Department of Pathology, JSS Medical College (constituent college of JSS University), Mysore, Karnataka, India.
Indian J Pathol Microbiol. 2012 Apr-Jun;55(2):170-4. doi: 10.4103/0377-4929.97853.
Primary localized cutaneous amyloidosis (PCA) is a relatively rare condition characterized by amyloid deposition in dermis without systemic involvement. Although, histopathological examination of the lesion reveals amorphous eosinophilic deposits in papillary dermis examination of congo red stained slides under polarized light will give definitive diagnosis
To study the clinicopathological features of cutaneous amyloidosis emphasizing the utility of polarized light in diagnosis.
A clinicopathological study of primary cutaneous amyloidosis over a period of 8 years was undertaken. All the cases, clinically diagnosed and histopathologically proven as cutaneous amyloidosis were stained with congo red and studied under polarized light.
Of the 45 cases of clinically suspected amyloidosis, 32 cases were proven histopathologically as primary cutaneous amyloidosis and confirmed by congo red stain under polarized light which showed apple green birefringence. Among the two types of PCA, lichen amyloidosis was the most common variant accounting to 65.63% with pure cases of macular amyloidosis accounting for only 15.63%. Biphasic amyloidosis was seen in 18.75%. Knee was the commonest site of involvement with pruritis being the most common symptom. Histopathologically, the most common findings were hyperkeratosis, irregular acanthosis and expansion of dermal papillae by amyloid deposits showing apple green birefringence under polarized microscope with congo red staining. Although, H and E stain gives a clue for the diagnosis of amyloid nevertheless congo red staining under polarized light forms a very sensitive and definitive method for confirmation.
原发性局限性皮肤淀粉样变（PCA）是一种相对罕见的疾病，其特征为淀粉样物质沉积于真皮而无全身受累。尽管病变的组织病理学检查显示乳头真皮中有无定形嗜酸性沉积物，但在偏振光下检查刚果红染色切片可做出明确诊断。
研究皮肤淀粉样变的临床病理特征，强调偏振光在诊断中的作用。
对原发性皮肤淀粉样变进行了为期8年的临床病理研究。所有临床诊断并经组织病理学证实为皮肤淀粉样变的病例均用刚果红染色，并在偏振光下进行研究。
在45例临床疑似淀粉样变的病例中，32例经组织病理学证实为原发性皮肤淀粉样变，并经偏振光下刚果红染色确认，显示苹果绿双折射。在两种PCA类型中，苔藓样淀粉样变是最常见的变异型，占65.63%，单纯斑状淀粉样变病例仅占15.63%。双相淀粉样变占18.75%。膝部是最常受累的部位，瘙痒是最常见的症状。组织病理学上，最常见的表现为角化过度、不规则棘层肥厚以及淀粉样沉积物使真皮乳头扩张，在偏振显微镜下刚果红染色显示苹果绿双折射。尽管苏木精和伊红染色可为淀粉样变的诊断提供线索，但偏振光下刚果红染色是一种非常敏感且明确的确诊方法。
