Department of Pathology, Massachusetts General Hospital Harvard Medical School, Boston, MA, USA.
Department of Pathology and Laboratory Medicine, Nagoya University Hospital, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8560, Japan.
Head Neck Pathol. 2022 Dec;16(4):1114-1123. doi: 10.1007/s12105-022-01471-4. Epub 2022 Jul 14.
Salivary gland intraductal papillary mucinous neoplasm (SG IPMN) is a recently proposed entity characterized by a papillary-cystic proliferation of mucin-producing cells. Because of overlapping histologic features and a clonal AKT1 p.E17K variant, SG IPMN has been presumed to be a precursor or a low-grade subtype of mucinous adenocarcinoma. NKX3.1 is a tumor suppressor gene located on chromosome 8p and is a known immunohistochemical marker of prostate epithelium and mucinous acinar cells of the intraoral salivary glands.
We retrieved 12 SG IPMN cases, and performed histologic and genetic analysis. Given the association of SG IPMN with mucinous acinar cells, we also investigated the performance of NKX3.1 as a marker of this tumor entity.
Diffuse and strong NKX3.1 expression was observed in all SG IPMN cases (12/12, 100%) as well as in normal mucinous acinar cells. In contrast, mucoepidermoid carcinoma and pancreatic IPMN cases as well as normal serous acinar cells were negative for NKX3.1. Genetically, 11 of 12 cases (92%) harbored an AKT1 p.E17K variant. A novel PTEN frameshift deletion (p.G36Dfs*18) was detected in the other single case. At least one of the histologic features implying malignant tumors, such as severe cellular atypia, brisk mitotic activity, high Ki-67 proliferating index, lymphovascular invasion, and lymph node metastasis, was detected in 6 SG IPMN cases (50%).
The findings suggest that SG IPMN is a low-grade subtype of mucinous adenocarcinoma which may be derived from mucinous acinar cells of the minor salivary gland.
唾液腺导管内乳头状黏液性肿瘤（SG IPMN）是一种新提出的实体，其特征为黏液产生细胞的乳头状-囊性增生。由于组织学特征重叠和 AKT1 p.E17K 变异克隆，SG IPMN 被认为是黏液性腺癌的前体或低级别亚型。NKX3.1 是位于 8p 染色体上的肿瘤抑制基因，是前列腺上皮和口腔内唾液腺黏液腺细胞的已知免疫组织化学标志物。
我们检索了 12 例 SG IPMN 病例，并进行了组织学和遗传学分析。鉴于 SG IPMN 与黏液腺细胞有关，我们还研究了 NKX3.1 作为该肿瘤实体标志物的性能。
所有 SG IPMN 病例（12/12，100%）以及正常黏液腺细胞均观察到弥漫性和强 NKX3.1 表达。相比之下，黏液表皮样癌和胰腺 IPMN 病例以及正常浆液腺细胞均为 NKX3.1 阴性。在遗传学上，12 例中有 11 例（92%）携带 AKT1 p.E17K 变异。在另一个单独的病例中检测到一个新的 PTEN 移码缺失（p.G36Dfs*18）。至少有一个提示恶性肿瘤的组织学特征，如严重的细胞异型性、活跃的有丝分裂活性、高 Ki-67 增殖指数、淋巴血管侵犯和淋巴结转移，在 6 例 SG IPMN 病例中（50%）被发现。
这些发现表明，SG IPMN 是一种低级别黏液性腺癌亚型，可能来源于小唾液腺的黏液腺细胞。
