Institute of Pathology, University Hospital, Krankenhausstrasse 8-10, 91054, Erlangen, Germany.
Department of Otorhinolaryngology, Head and Neck Surgery, Bundeswehrkrankenhaus, Berlin, Germany.
Head Neck Pathol. 2021 Mar;15(1):361-367. doi: 10.1007/s12105-020-01181-9. Epub 2020 Jun 5.
Porocarcinoma (synonym: malignant eccrine poroma) is a rare aggressive carcinoma type with terminal sweat gland duct differentiation. The squamous variant of porocarcinoma is even less frequent and might be indistinguishable from conventional squamous cell carcinoma (SCC). We herein describe the first case of a carcinoma presenting as a primary parotid gland malignancy in a 24-year-old male without any other primary tumor. Total parotidectomy and neck dissection were performed followed by adjuvant chemoradiation. The patient remained alive and well 10 months after diagnosis. Histology showed keratinizing SCC infiltrating extensively the parotid gland with subtle poroid cell features. Oncogenic HPV infection was excluded by DNA-based testing. NGS analysis using the TruSight RNA fusion panel (Illumina) revealed a novel YAP1-MAML2 gene fusion. This gene fusion was reported recently in a subset of cutaneous porocarcinoma and poroma. This case of poroid SCC (or squamoid porocarcinoma) adds to the differential diagnosis of SCC presenting as parotid gland tumor and highlights the value of molecular testing in cases with unusual presentation.
汗管癌（同义词：恶性外分泌汗腺瘤）是一种罕见的侵袭性癌，具有终末汗腺导管分化。汗管癌的鳞状变体更为罕见，可能与常规鳞状细胞癌（SCC）无法区分。本文描述了首例 24 岁男性发生于腮腺的原发性恶性肿瘤，无其他原发性肿瘤。行全腮腺切除术和颈部淋巴结清扫术，然后辅助放化疗。诊断后 10 个月患者仍存活且状况良好。组织学显示角化型 SCC 广泛浸润腮腺，具有微妙的汗管细胞特征。通过基于 DNA 的检测排除了致癌 HPV 感染。使用 TruSight RNA 融合panel（Illumina）进行 NGS 分析显示了一种新型 YAP1-MAML2 基因融合。该基因融合最近在一组皮肤汗管癌和汗管瘤中报道过。这种汗管鳞癌（或鳞状汗管癌）增加了 SCC 作为腮腺肿瘤的鉴别诊断，并强调了在表现不典型的病例中进行分子检测的价值。
