Department of Pathology, M. D. Anderson Cancer Center, Houston, TX, USA.
Histopathology. 2014 Dec;65(6):897-907. doi: 10.1111/his.12492. Epub 2014 Oct 30.
We have observed glandular downgrowth in some gastric neuroendocrine tumours (NETs), in which nonneoplastic appearing gastric glands are admixed with submucosal neuroendocrine nests, that could potentially be confused with composite tumours.
We reviewed 68 gastric NETs with at least submucosal invasion, and evaluated associations between glandular downgrowth, clinical parameters (age, gender, NET setting) and tumour characteristics (size, depth of invasion, grade). Controls included 45 duodenal NETs. Glandular downgrowth was present in 28 (41%) gastric NETs but only 2 (4.4%) duodenal NETs (P < 0.0001). It was not related to age, gender, hypergastrinemia (downgrowth present in 43% of NETs arising in autoimmune gastritis, 41% of Zollinger-Ellison syndrome, 36% of sporadic NETs), tumour size, depth of invasion, or grade. Glandular downgrowth was confined to the submucosa even though 12 (18%) gastric NETs invaded muscularis propria. Submucosal gastric glands (pyloric type in 79%, intestinal in 50%, fundic in 29%) showed metaplastic changes similar to overlying mucosa, were usually mitotically inactive (64% of cases lacked mitotic figures), were geographically restricted to the NET, and never metastasized.
Our findings support the frequent occurrence and nonneoplastic nature of glandular downgrowth in gastric NETs, which should not be mistaken for composite tumours.
我们观察到一些胃神经内分泌肿瘤（NET）中存在腺体下生长，其中非肿瘤性胃腺与黏膜下神经内分泌巢混合存在，这可能与复合性肿瘤相混淆。
我们回顾了 68 例至少有黏膜下浸润的胃 NET，并评估了腺体下生长与临床参数（年龄、性别、NET 背景）和肿瘤特征（大小、浸润深度、分级）之间的关联。对照组包括 45 例十二指肠 NET。腺体下生长存在于 28 例（41%）胃 NET 中，但仅存在于 2 例（4.4%）十二指肠 NET 中（P<0.0001）。它与年龄、性别、高胃泌素血症无关（在自身免疫性胃炎、Zollinger-Ellison 综合征、散发性 NET 中发生的 NET 中，有 43%、41%和 36%存在腺体下生长），与肿瘤大小、浸润深度或分级无关。腺体下生长局限于黏膜下层，尽管 12 例（18%）胃 NET 侵犯了肌层。黏膜下层的胃腺（79%为幽门型、50%为肠型、29%为胃底型）显示出与上覆黏膜相似的化生改变，通常无有丝分裂活性（64%的病例缺乏有丝分裂象），在空间上局限于 NET，从不发生转移。
我们的发现支持胃 NET 中腺体下生长的频繁发生和非肿瘤性质，不应将其误诊为复合性肿瘤。
