Begin L R, Allaire G S
Department of Pathology, McGill University.
J Submicrosc Cytol Pathol. 1996 Jan;28(1):121-31.
Two cases of pure insular (poorly differentiated) carcinoma of the thyroid are reported, with emphasis on their ultrastructure. Notwithstanding their solid/primitive histologic character, a high degree of structural organization and differentiation was present at the submicroscopic level, namely a highly developed cytosecretory apparatus and numerous abortive/rudimentary follicles. A prominent inclusion/dot-like pattern (often paranuclear) of thyroglobulin immunoreactivity was observed, ultrastructurally corresponding to the following features: a) abortive/rudimentary follicular lumina with abundant periluminal dense bodies, and with varying amounts of colloid and microvilli, both at the intercellular and intracellular level; b) large inclusions of fibrillar/lamellar or finely granular material within dilated cisternae of endoplasmic reticulum and possibly of lysosomal nature as well, likely reflecting altered production and/or storage of thyroglobulin substrate. One tumor had many cytophenotypical attributes ascribed to differentiated papillary carcinoma (PC), whereas the other tumor was more analogous to differentiated follicular carcinoma (FC). The present study supports the concept that the insular pattern is a common pathway of dedifferentiation for follicular cell neoplasia of both PC and FC types, yet with maintenance of most of their respective cytophenotypical features, and with evidence of a high level of differentiation/maturation at the submicroscopic level.
本文报告了两例甲状腺纯岛状（低分化）癌，并着重介绍了其超微结构。尽管它们具有实性/原始的组织学特征，但在亚微观水平上仍存在高度的结构组织和分化，即高度发达的细胞分泌装置和大量发育不全/原始的滤泡。观察到甲状腺球蛋白免疫反应呈现出显著的包涵体/点状模式（通常为核旁），超微结构上对应以下特征：a）发育不全/原始的滤泡腔，其周缘有丰富的致密小体，在细胞间和细胞内水平均有不同数量的胶体和微绒毛；b）内质网扩张的潴泡内有大量纤维状/层状或细颗粒状物质的包涵体，可能也具有溶酶体性质，这可能反映了甲状腺球蛋白底物的产生和/或储存发生了改变。其中一个肿瘤具有许多归属于分化型乳头状癌（PC）的细胞表型特征，而另一个肿瘤则更类似于分化型滤泡癌（FC）。本研究支持这样一种观点，即岛状模式是PC和FC两种类型滤泡细胞肿瘤去分化的常见途径，但同时保留了它们各自大部分的细胞表型特征，并且在亚微观水平上有高度分化/成熟的证据。
