Abstract:
Macular amyloidosis is a common type of primary localized cutaneous amyloidosis. We present a case report of a 74-year-old patient with no significant past medical history who was evaluated for dark macules and pruritus for over a year. On exam, follicular-based brown macules on the upper and lower back, bilateral shoulders, and bilateral dorsal upper arms were noted. The morphology and distribution of follicular-based macules was unusual, so the differential included follicular lichen planus, follicular eczema, and macular amyloidosis. Punch biopsy showed deposits of eosinophilic fibrillary material along with pigmentary incontinence in the papillary dermis, consistent with macular amyloidosis. Additionally, there was some trapping of the adnexal structures with atrophy of the periadnexal fat in the reticular dermis. In macular amyloidosis keratin, intermediate filaments such as cytokeratin serve as the amyloid precursors which deposit in the superficial dermis. Characteristically, macular amyloidosis presents as hyperpigmented macules or patches, often in a \"rippled\" linear pattern. This case highlights a rare presentation of macular amyloidosis because of the atypical follicular involvement and emphasizes the variety of presentations for localized cutaneous amyloidosis. Additionally, new treatment options such as Janus Kinase inhibitors and their potential role in the pathological pathway are discussed.
摘要:
黄斑淀粉样变性是一种常见类型的原发性局限性皮肤淀粉样变性。我们提供了一例病例报告,其中一名74岁的患者没有明显的既往病史,对其进行了一年多的深色黄斑和瘙痒评估。在考试中,上背部和下背部的滤泡型棕色斑疹,双边肩,并注意到双侧背侧上臂。滤泡性黄斑的形态和分布异常,所以差异包括毛囊扁平苔藓,滤泡性湿疹,和黄斑淀粉样变性。穿刺活检显示嗜酸性原纤维材料沉积,并在乳头状真皮中伴有色素性失禁,与黄斑淀粉样变性一致。此外,在网状真皮中,附件结构被捕获,附件周围脂肪萎缩。在黄斑淀粉样变性角蛋白中,中间细丝如细胞角蛋白作为淀粉样蛋白前体,沉积在浅层真皮中。典型地,黄斑淀粉样变性表现为色素沉着的黄斑或斑块,通常呈“波纹”线性模式。由于非典型的滤泡受累,该病例突出了黄斑淀粉样变性的罕见表现,并强调了局部皮肤淀粉样变性的各种表现。此外,讨论了Janus激酶抑制剂等新的治疗选择及其在病理途径中的潜在作用。