Background

The histologic findings of scalp involvement in dermatomyositis are not well characterized on account of a lack of large series.

Objective

To systematize the histologic features of scalp involvement in dermatomyositis on horizontal and vertical sections.

Methods

A descriptive, prospective, cross-sectional study recruited 31 patients with pathologically and serologically confirmed dermatomyositis in Mexico City, Mexico, from June 2014 to June 2015. A total of 36 scalp biopsy specimens from 20 patients with scalp involvement in dermatomyositis were processed as 20 vertical and 16 horizontal sections.

Results

Dilated capillaries and diffuse mucin deposition were detected in all biopsy specimens, followed by interface dermatitis. Partial or segmental thickening of the basement membrane, hyperkeratosis, atrophic epidermis, and acrosyringeal hypergranulosis with hyperkeratosis were other very common findings. Preserved follicular architecture, with intact or slightly atrophic sebaceous glands, was present in most horizontal sections. There was decreased follicular density, with a terminal-to-vellus ratio of 4:1 and telogen count of 10.3%. Eosinophils were present in 15% and 25% of horizontal and vertical sections, respectively.

Limitations

No special stains performed.

Conclusion

Scalp involvement in dermatomyositis shows nonscarring pattern on horizontal sections that is consistent with chronic telogen effluvium. Telangiectasia and mucin are universal histologic features; eosinophils and acrosyringeal hypergranulosis with hyperkeratosis are new findings.

中文翻译：

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皮肌炎患者头皮受累的头皮活检标本的水平和垂直截面

背景

由于缺乏大的序列，头皮受累于皮肌炎的组织学发现没有得到很好的表征。

客观的

为了使皮肌炎的头皮受累组织在水平和垂直方向上的组织学特征得以系统化。

方法

一项描述性，前瞻性，横断面研究从2014年6月至2015年6月在墨西哥墨西哥城招募了31例经病理学和血清学确诊的皮肌炎患者。从20例涉及皮肌炎的头皮患者的36例头皮活检标本中，共处理了20例垂直部分和16个水平部分。

结果

在所有活检标本中均检测到毛细血管扩张和粘液弥漫性沉积，然后出现界面皮炎。基底膜的部分或节段增厚，过度角化，萎缩性表皮和伴有过度角化的顶突，高密度脂蛋白血症是其他很常见的发现。大多数水平切片中均保留了完整的或略有萎缩性皮脂腺的滤泡结构。卵泡密度降低，末端与绒毛之比为4：1，端粒数为10.3％。嗜酸性粒细胞分别占水平和垂直切片的15％和25％。

局限性

没有执行特殊的污渍。

结论

皮肌炎的头皮受累显示出水平部位无疤痕，这与慢性端粒细胞流出物一致。毛细血管扩张和粘蛋白是普遍的组织学特征。嗜酸性粒细胞和肩突过度肉芽肿伴角化过度是新发现。