癌瘤类肿瘤极少出现在节肢动物中，特别是在甲壳类动物中更是如此。因此，人们认为这些动物具有一些有效的癌症预防机制。然而，在甲壳类动物中却描述了数种癌瘤类肿瘤，但仅限于十足目。我们在寄生的囊甲科动物Peltogaster paguri（角形亚綱）中发现了一个肿瘤，并描述了其组织学结构。在P. paguri主干中发现了一个球形细胞团，主要由圆形细胞和大量具有明显核仁和稀疏染色质核的细胞组成，还有纺锤体状的染色体细胞。在这个区域观察到了大量的有丝分裂。这种组织结构与根头动物类肿瘤完全不同。根据所获得的组织学数据，我们认为这种肿瘤是一种类癌瘤。这是首次在根头动物以及所有甲壳类动物中发现的肿瘤的报道。版权所有© 2023 Elsevier Inc.。保留所有权利。

Cancer-like neoplasms are extremely rarely present in arthropods, particularly in crustaceans. Thus, it is assumed that these animals have some efficient cancer-preventing mechanisms. However, several cases of cancer-like neoplasms are described in crustaceans, though only for the Decapoda. We identified a tumor in the parasitic barnacle Peltogaster paguri (Cirripedia: Rhizocephala), and described its histological structure. A spherical cell mass, consisting mostly of roundish cells with big translucent nuclei, prominent nucleoli, and sparse chromatin, and of cells with condensed chromosomes, was found in the main trunk of the P. paguri rootlet system. Numerous mitoses were observed in this area. Such tissue organization is utterly uncharacteristic of the Rhizocephala. Based on acquired histological data, we assume that this tumor is a cancer-like neoplasm. This is the first report of a tumor identified in the rhizocephalans, as well as in non-decapod crustaceans as a whole.Copyright © 2023 Elsevier Inc. All rights reserved.