The utility of electron microscopy in dermatopathology: cutaneous SMARCA4-deficient dedifferentiated large cell neuroendocrine carcinoma.

IF 1.2 4区医学 Q4 MICROSCOPY

Ultrastructural Pathology Pub Date : 2026-01-01 Epub Date: 2026-09-09 DOI:10.1080/01913123.2026.2726907

Katrina J Jiang, Jawaria Hassan, Daisy E Escobar, J Harrison Howard, Guillermo A Herrera, Kurt J Knowles

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Abstract

We report two cases of SMARCA4-deficient LCNEC (SD-LCNEC) presenting as cutaneous masses: an asymptomatic 3 cm right flank subcutaneous nodule in a 59-year-old male with concurrent pulmonary mass and metastases to cervical lymph node, and a painful 5 × 10 cm ulcerated left perineal mass in a 56-year-old female with hidradenitis suppurativa and concurrent pulmonary small cell carcinoma. To date, SD-LCNEC has been described almost exclusively as a thoracic malignancy. While various SMARCA4-deficient undifferentiated neoplasms (SD-UMN) have been identified in the skin, none have been definitively characterized as neuroendocrine. In both cases, neuroendocrine marker expression was markedly reduced on immunohistochemistry, precluding IHC-based classification as LCNEC. Electron microscopy performed on formalin-fixed paraffin-embedded tissue demonstrated abundant membrane-bound dense-core neurosecretory granules and well-formed desmosomes in both cases, ultrastructurally confirming the diagnosis. To our knowledge, these are the first reported cases of cutaneous SD-LCNEC confirmed by electron microscopy.

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电子显微镜在皮肤病理学中的应用：皮肤smarca4缺陷去分化大细胞神经内分泌癌。

我们报告了两例smarca4缺陷LCNEC (SD-LCNEC)，表现为皮肤肿块：59岁男性，无症状的3厘米右侧皮下结节，并发肺肿块并转移到颈部淋巴结；56岁女性，化脓性汗腺炎并发肺小细胞癌，疼痛的5 × 10厘米溃疡性左侧会阴肿块。迄今为止，SD-LCNEC几乎完全被描述为胸部恶性肿瘤。虽然在皮肤中发现了各种smarca4缺陷未分化肿瘤（SD-UMN），但没有一种被明确表征为神经内分泌。在这两种情况下，免疫组织化学显示神经内分泌标志物表达明显降低，排除了基于免疫组化的LCNEC分类。经福尔马林固定石蜡包埋组织电镜检查，两例均可见丰富的膜结合致密核神经分泌颗粒和结构良好的桥粒，在超微结构上证实了诊断。据我们所知，这是第一例经电子显微镜证实的皮肤SD-LCNEC病例。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Ultrastructural Pathology 医学-病理学

CiteScore

2.00

自引率

10.00%

发文量

审稿时长

6-12 weeks

期刊介绍： Ultrastructural Pathology is the official journal of the Society for Ultrastructural Pathology. Published bimonthly, we are the only journal to be devoted entirely to diagnostic ultrastructural pathology. Ultrastructural Pathology is the ideal journal to publish high-quality research on the following topics: Advances in the uses of electron microscopic and immunohistochemical techniques Correlations of ultrastructural data with light microscopy, histochemistry, immunohistochemistry, biochemistry, cell and tissue culturing, and electron probe analysis Important new, investigative, clinical, and diagnostic EM methods.