Cornejo Kristine M, Lagana Frances J, Deng April
Departments of *Pathology, and †Orthopedics, University of Massachusetts Medical School, Worcester, MA.
Am J Dermatopathol. 2015 Nov;37(11):e129-33. doi: 10.1097/DAD.0000000000000307.
Primary, localized cutaneous amyloidosis includes macular, lichen, and nodular (tumefactive) types in which the amyloid deposits are limited to the dermis without systemic involvement. The material in lichen and macular amyloidosis is derived from epidermal keratinocytes [keratinocyte-derived amyloid (AK)], whereas that in nodular amyloidosis is derived from immunoglobulin light-chains amyloid (AL). Primary, localized cutaneous nodular amyloidosis (PLCNA) is a form of primary, localized cutaneous amyloidosis that has been associated with a risk of progression to systemic amyloidosis. We report an unusual case of nodular AK-type amyloid deposited in the dermis of the feet. The patient is a 60-year-old woman with asymptomatic verrucoid-like lesions present around the medial and lateral aspects of the bilateral heels for 1-2 years. A biopsy showed massive deposition of eosinophilic amorphous material in the papillary and reticular dermis. The material stained positive for Congo red with apple-green birefringence on polarized light. It was also positive for pan-cytokeratin and negative for kappa and lambda light-chain immunostains. An extensive workup was negative for systemic involvement. Lipid chromatography tandem mass spectrometry confirmed that the deposition was AK-type amyloid. We believe that this is the first case of PLCNA with AK deposition. This entity should be included in the differential diagnosis of PLCNA so that an extensive systemic workup may be avoided.
原发性局限性皮肤淀粉样变包括斑疹型、苔藓型和结节型（肿瘤样型），其中淀粉样沉积物局限于真皮，无全身受累。苔藓型和斑疹型淀粉样变中的物质来源于表皮角质形成细胞[角质形成细胞衍生的淀粉样蛋白（AK）]，而结节型淀粉样变中的物质来源于免疫球蛋白轻链淀粉样蛋白（AL）。原发性局限性皮肤结节型淀粉样变（PLCNA）是原发性局限性皮肤淀粉样变的一种形式，与进展为系统性淀粉样变的风险相关。我们报告了一例罕见的结节型AK型淀粉样蛋白沉积于足部真皮的病例。患者为60岁女性，双侧足跟内侧和外侧出现无症状的疣状样皮损1 - 2年。活检显示乳头层和网状真皮中有大量嗜酸性无定形物质沉积。该物质刚果红染色阳性，偏振光下呈苹果绿双折射。全细胞角蛋白染色也呈阳性，κ和λ轻链免疫染色呈阴性。全面检查未发现全身受累。脂质色谱串联质谱法证实沉积的是AK型淀粉样蛋白。我们认为这是首例伴有AK沉积的PLCNA病例。该实体应纳入PLCNA的鉴别诊断，以便避免进行全面的全身检查。
