Division of Diagnostic Pathology, Yokohama City University Hospital, Yokohama, Japan.
Department of Pathology, Yokohama University Graduate School of Medicine, Yokohama, Japan.
Histopathology. 2018 Mar;72(4):609-618. doi: 10.1111/his.13397. Epub 2017 Dec 14.
Psammoma bodies are concentrically lamellated microscopic structures made of calcium. They are commonly observed in papillary carcinomas of the thyroid gland and serous papillary adenocarcinomas of the ovary, but are also occasionally detected in lung adenocarcinomas. Only one study, published in 1972, has systematically described the significance of psammoma bodies in lung adenocarcinomas. The aim of this study was to update the significance of psammoma bodies in lung adenocarcinomas from a modern perspective.
Psammoma bodies were detected in 7.2% (59/822) of the adenocarcinomas examined, among which the papillary (20.3%, 12/59) and acinar (44.1%, 26/59) histological subtypes, with the feature of a terminal respiratory unit (91.5%, 54/59), were dominant. Malignant potential (cell growth activity measured by Ki67 labelling, lymph node metastasis, and postoperative survival) did not significantly differ between adenocarcinomas with and without psammoma bodies. On the basis of cytogenetic features, adenocarcinomas with psammoma bodies were preferentially affected by tyrosine kinase inhibitor (TKI)-targetable driver mutations [EGFR (69.8%, 37/53), ALK (13.2%, 7/53), and ROS1 (1.9%, 1/53)]. Multivariate analyses confirmed that psammoma bodies may constitute an independent predictor for these mutations, particularly EGFR and ALK mutations.
Psammoma bodies may predict a favourable response of lung adenocarcinomas to TKIs.
砂粒体是由钙组成的同心层状微观结构。它们常见于甲状腺乳头状癌和卵巢浆液性乳头状腺癌，但偶尔也可见于肺腺癌。仅有一项发表于 1972 年的研究系统地描述了砂粒体在肺腺癌中的意义。本研究旨在从现代角度更新肺腺癌中砂粒体的意义。
在 822 例腺癌中，有 7.2%（59/822）检测到砂粒体，其中以具有终末呼吸单位特征的乳头状（20.3%，12/59）和腺泡状（44.1%，26/59）组织学亚型为主。砂粒体阳性的腺癌（通过 Ki67 标记测量的细胞生长活性、淋巴结转移和术后生存）与砂粒体阴性的腺癌之间的恶性潜能无显著差异。基于细胞遗传学特征，具有砂粒体的腺癌更易受酪氨酸激酶抑制剂（TKI）靶向驱动突变的影响[EGFR（69.8%，37/53）、ALK（13.2%，7/53）和 ROS1（1.9%，1/53）]。多变量分析证实，砂粒体可能是这些突变（尤其是 EGFR 和 ALK 突变）的独立预测因子。
砂粒体可能预示肺腺癌对 TKI 的治疗反应良好。
