背景:胸膜肺母细胞瘤(PPB)是一种罕见的,侵略性,原发性胸腔内恶性肿瘤常见于婴儿期和儿童早期。由于预后和治疗差异显着,因此与先天性囊性肺病变的准确区分至关重要。细胞学特征很少被描述。建立细胞诊断由于其稀有性而具有挑战性,缺乏意识,和多种形态模拟物。
方法:这是一项为期8年的回顾性研究。在组织病理学和细胞病理学数据库中搜索所有儿科PPB病例。对相应的细胞学样本进行了审查,以确定可以帮助区分PPB及其模拟物的特征。
结果:在研究期间报告了6例小儿PPB。其中,四例(66.7%)出现在胸内,和两个(33.3%)作为胸膜基肿块。细胞学涂片显示圆形卵圆形肿瘤细胞的离散分散和血管周围排列,背景为嗜酸性基质。肿瘤细胞呈轻度多形性(n=3),细胞核呈圆形,细染色质,不显眼的核仁,和很少的细胞质;然而,三例显示明显的发育不全,每个显示坏死和横纹肌样分化。在免疫细胞化学(4/6),这些对波形蛋白和结蛋白呈阳性,对WT1、嗜铬粒蛋白呈阴性,SALL4,细胞角蛋白,CD45和CD99。FISH(1/6)未显示N-Myc扩增。
结论:了解PPB的特征性细胞形态学和免疫细胞化学特征对于建立具有适当临床放射相关性的及时准确的细胞诊断至关重要。
BACKGROUND: Pleuropulmonary blastoma (PPB) is a rare, aggressive, primary intrathoracic malignancy typically seen in infancy and early childhood. Accurate distinction from congenital cystic lung lesions is crucial due to significant prognostic and therapeutic differences. Cytologic features have rarely been described. Establishing a cytodiagnosis is challenging owing to its rarity, lack of awareness, and multiple morphologic mimics.
METHODS: This was a retrospective study conducted over 8 years. The histopathology and cytopathology databases were searched for all pediatric PPB cases. The corresponding cytologic samples were reviewed to identify characteristic features that can help distinguish PPB from its mimics.
RESULTS: There was a total of six cases of pediatric PPB reported during the study period. Of these, four (66.7%) presented as intrathoracic, and two (33.3%) as pleural-based masses. Cytology smears showed discretely scattered and perivascular arrangements of round-oval tumor cells with background eosinophilic stromal material. The tumor cells were mildly pleomorphic (n = 3) with round nuclei, fine chromatin, inconspicuous nucleoli, and scanty cytoplasm; however, three cases showed marked anaplasia, and one each showed necrosis and rhabdoid differentiation. On immunocytochemistry (4/6), these were positive for vimentin and desmin and negative for WT1, chromogranin, SALL4, cytokeratin, CD45, and CD99. FISH (1/6) did not show N-Myc amplification.
CONCLUSIONS: Knowledge of the characteristic cytomorphological and immunocytochemical features of PPB is vital to establish a prompt and accurate cytodiagnosis with appropriate clinicoradiologic correlation.