Pathology Division, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
Pathol Int. 2010 Dec;60(12):765-73. doi: 10.1111/j.1440-1827.2010.02596.x. Epub 2010 Sep 14.
The histopathology of small metastases is thought to reflect the early metastatic process. To clarify the morphological features of early metastatic tumor progression, we analyzed the histological heterogeneity of many small intrapulmonary metastases. Histological typing based on the World Health Organization classification (bronchioloalveolar carcinoma, acinar, papillary, and solid subtype) was used to evaluate 234 metastases from the primary lung adenocarcinomas of 139 patients. The predominant subtype of metastasis 3 mm or less in diameter was bronchioloalveolar carcinoma when the primary lesion was diagnosed as predominant bronchioloalveolar carcinoma, acinar, and papillary subtype. When the histology of the primary tumor was predominantly a solid subtype, the predominant subtype of metastatic tumor was also a solid subtype. However, analysis of metastases that were more than 3 mm showed that the predominant subtype of the metastasis reflected the predominant subtype of the primary tumor. Furthermore, we evaluated the number of subtypes in primary and metastatic tumors. As the metastasis grew larger, the number of subtypes in the metastatic lesion increased and came close to the number composed in the primary lesion. These findings suggest that implanted cancer cells display lepidic growth in the early metastatic phase and recapitulate the morphological heterogeneity of the original tumor as the metastasis enlarges.
小转移灶的组织病理学被认为反映了早期转移过程。为了阐明早期转移肿瘤进展的形态学特征，我们分析了许多肺内小转移灶的组织学异质性。基于世界卫生组织分类（细支气管肺泡癌、腺泡型、乳头状和实体亚型）的组织学分型用于评估 139 名患者的原发性肺腺癌的 234 个转移灶。当原发性病变被诊断为以细支气管肺泡癌为主、腺泡型和乳头状为主时，直径为 3 毫米或以下的转移灶的主要亚型为细支气管肺泡癌。当原发性肿瘤的组织学主要为实体亚型时，转移瘤的主要亚型也是实体亚型。然而，对直径大于 3 毫米的转移灶进行分析表明，转移灶的主要亚型反映了原发性肿瘤的主要亚型。此外，我们评估了原发性和转移性肿瘤中的亚型数量。随着转移灶的增大，转移灶中亚型的数量增加，并接近原发性病变中的组成数量。这些发现表明，植入的癌细胞在早期转移阶段表现出贴壁生长，并随着转移灶的增大而重现原始肿瘤的形态异质性。
