Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
J Cutan Pathol. 2021 Mar;48(3):403-410. doi: 10.1111/cup.13924. Epub 2020 Dec 14.
Porocarcinoma is the malignant counterpart of poroma, a benign tumor derived from the eccrine or apocrine units. In contrast to poroma, porocarcinoma is rare and its diagnosis may be challenging. Recent work has identified YAP1-associated gene fusions in most poromas, and a subset of porocarcinomas. These included YAP1-MAML2 and YAP1-NUTM1, the latter being enriched in porocarcinomas over poromas.
We studied YAP1 C-terminus and NUT immunohistochemistry in a cohort of 12 porocarcinomas, 10 poromas, 10 squamous cell carcinomas, and 6 hidradenocarcinomas.
Seven of 12 (58%) porocarcinomas showed loss of YAP1 C-terminus expression, consistent with a YAP1 fusion. Of these seven, five showed NUT positivity, implying the presence of the YAP1-NUTM1 fusion. One of 12 (8%) cases showed NUT positivity, but retention of YAP1 C-terminus expression, consistent with a non-YAP1 NUT-associated fusion. Eight of 10 (80%) poromas showed loss of YAP1 C-terminus expression and negative NUT staining, consistent with non-NUT YAP1 fusions. All squamous cell carcinomas and hidradenocarcinomas retained YAP1 C-terminus expression and were negative for NUT.
YAP1 C-terminus and NUT immunohistochemistry may be helpful in the diagnosis of porocarcinoma, with the combination of YAP1 C-terminus loss and NUT positivity being particularly informative.
派杰氏癌是派杰氏病的恶性对应物，是一种源自外分泌或顶泌单元的良性肿瘤。与派杰氏病不同，派杰氏癌很少见，其诊断可能具有挑战性。最近的研究已经在大多数派杰氏瘤和一部分派杰氏癌中发现了 YAP1 相关基因融合。这些融合包括 YAP1-MAML2 和 YAP1-NUTM1，后者在派杰氏癌中比派杰氏瘤更丰富。
我们研究了 12 例派杰氏癌、10 例派杰氏瘤、10 例鳞状细胞癌和 6 例汗腺瘤中 YAP1 C 末端和 NUT 的免疫组化。
12 例派杰氏癌中有 7 例（58%）显示 YAP1 C 末端表达缺失，符合 YAP1 融合。这 7 例中有 5 例显示 NUT 阳性，表明存在 YAP1-NUTM1 融合。12 例中有 1 例（8%）显示 NUT 阳性，但 YAP1 C 末端表达保留，符合非 YAP1 NUT 相关融合。10 例派杰氏瘤中有 8 例（80%）显示 YAP1 C 末端表达缺失和 NUT 染色阴性，符合非 NUT YAP1 融合。所有鳞状细胞癌和汗腺瘤均保留 YAP1 C 末端表达且 NUT 阴性。
YAP1 C 末端和 NUT 免疫组化在派杰氏癌的诊断中可能有帮助，YAP1 C 末端缺失和 NUT 阳性的组合特别有信息。
