*Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN †The James Homer Wright Pathology Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, MA.
Am J Surg Pathol. 2014 May;38(5):689-97. doi: 10.1097/PAS.0000000000000171.
A total of 180 consecutive testicular cancers containing a component of embryonal carcinoma (EC) were reviewed to assess the morphologic features of the EC component. EC mostly (84%) occurred as a component of a mixed germ cell tumor, but 16% were pure. Solid (55%), glandular (17%), and papillary (11%) were the most common primary patterns (predominant architectural pattern occupying at least 50%), whereas other less common primary patterns included nested (3%), micropapillary (2%), anastomosing glandular (1%), sieve-like glandular (<1%), pseudopapillary (<1%), and blastocyst-like (<1%). Occasionally, EC developed predominantly in the context of polyembryoma-like (6%) and diffuse embryoma-like ("necklace" pattern) (3%) proliferations. In all, 69% had secondary architectural patterns, the most frequent being glandular (31%), papillary (14%), and solid (12%). An appliqué appearance, in which smudged and degenerate-appearing EC cells appear "applied" to the tumor periphery, was common (67%). EC cells with clear cytoplasm and distinct cell membranes (seminoma-like) were present in 11%, and dense lymphocytic infiltration and granulomatous inflammation were seen in 7% and 3%, respectively. Features simulating yolk sac tumor and teratoma were also seen: pseudoendodermal sinuses (34%), columnar cells (20%), and secretory-type subnuclear cytoplasmic vacuoles (6%). Syncytiotrophoblast cells were frequent (46%). Intratubular EC, typically partly necrotic and calcified, occurred in 24%. The associated stroma was more often non-neoplastic (53%) than neoplastic (29%). The rarity of some poorly characterized patterns of EC (micropapillary, blastocyst-like, anastomosing glandular, and sieve-like glandular) and some that overlap with those of other germ cell tumors, as well as some uncommon cytologic features, may result in misinterpretation, potentially impacting management. The association with other more common patterns and typical cytologic features, together with simple awareness of these variant morphologies, are helpful in establishing an accurate diagnosis of EC.
共回顾了 180 例连续的包含胚胎癌（EC）成分的睾丸癌，以评估 EC 成分的形态学特征。EC 主要（84%）作为混合生殖细胞肿瘤的一个成分出现，但 16%为纯 EC。实性（55%）、腺样（17%）和乳头状（11%）是最常见的主要形态（至少 50%的主要结构模式），而其他不太常见的主要形态包括巢状（3%）、微乳头状（2%）、吻合性腺样（1%）、筛状腺样（<1%）、假乳头状（<1%）和胚泡样（<1%）。偶尔，EC 主要在多胚瘤样（6%）和弥漫性胚胎瘤样（“项链”样）（3%）增生的背景下发展。总的来说，69%有二级结构模式，最常见的是腺样（31%）、乳头状（14%）和实性（12%）。EC 细胞模糊和退化外观的“贴附”外观很常见（67%）。存在透明细胞质和清晰细胞膜的（精原细胞瘤样）EC 细胞占 11%，致密淋巴细胞浸润和肉芽肿性炎症分别占 7%和 3%。还可见模拟卵黄囊肿瘤和畸胎瘤的特征：假内胚窦（34%）、柱状细胞（20%）和分泌型亚核细胞质空泡（6%）。合体滋养细胞细胞很常见（46%）。管内 EC，通常部分坏死和钙化，发生在 24%。相关的基质更常是非肿瘤性的（53%）而不是肿瘤性的（29%）。一些特征不明确的 EC 形态（微乳头状、胚泡样、吻合性腺样和筛状腺样）和一些与其他生殖细胞肿瘤重叠的形态以及一些不常见的细胞学特征，可能导致误诊，从而潜在影响治疗。与其他更常见的形态和典型的细胞学特征的关联，以及对这些变异形态的简单认识，有助于建立 EC 的准确诊断。
