Department of Pathology, Nagasaki University School of Medicine and Graduate School of Biomedical Science, Nagasaki, Japan.
Department of Internal Medicine, National Hospital Organization, Saga National Hospital, Saga, Japan.
Histopathology. 2018 Sep;73(3):521-528. doi: 10.1111/his.13639. Epub 2018 Jun 6.
Gut-associated lymphoid tissue (GALT) carcinoma is a rare colorectal tumour that arises in the epithelium covering GALT. GALT carcinoma is a differentiated tubular adenocarcinoma with dense lymphoid tissue with a characteristically well-demarcated margin. To date, 26 cases of GALT carcinoma, including the three cases discussed here, have been reported. Most (24 of 26) were discovered at early stages and none of the cases have documented any metastases. This suggests that GALT carcinoma may have a favourable prognosis. It is hypothesised that GALT carcinoma originates from M cells in specialised epithelia covering GALT. However, this hypothesis has yet to be confirmed.
In this study, we examined three cases of GALT carcinoma by immunohistochemistry detection of glycoprotein 2, a specific marker for M cells, and electron microscopy. Our findings showed that the tumour cells of GALT carcinoma in all three cases were negative for M cells. We thus concluded that GALT carcinoma may be a tubular adenocarcinoma arising by chance in the GALT. This unique carcinoma is a diferentiated adenocarcinoma that grows slowly with the development of GALT.
We propose that GALT carcinoma should be classified separately because of its histological setting and good prognosis.
肠相关淋巴组织（GALT）癌是一种罕见的结直肠肿瘤，起源于覆盖 GALT 的上皮细胞。GALT 癌是一种分化良好的管状腺癌，伴有密集的淋巴组织，具有特征性的清晰边界。迄今为止，已经报道了 26 例 GALT 癌，包括本文讨论的 3 例。大多数（26 例中的 24 例）在早期被发现，没有任何病例记录到转移。这表明 GALT 癌可能具有良好的预后。据推测，GALT 癌起源于覆盖 GALT 的特殊上皮细胞中的 M 细胞。然而，这一假设尚未得到证实。
在本研究中，我们通过免疫组织化学检测糖蛋白 2（M 细胞的特异性标志物）和电子显微镜检查了 3 例 GALT 癌。我们的研究结果显示，所有 3 例 GALT 癌的肿瘤细胞均为 M 细胞阴性。因此，我们得出结论，GALT 癌可能是 GALT 中偶然发生的管状腺癌。这种独特的癌是一种分化良好的腺癌，随着 GALT 的发育而缓慢生长。
我们建议将 GALT 癌单独分类，因为其组织学特征和良好的预后。
