Nahm Ji Hae, Yoon Gun, Do Sung-Im, Kim Hyun-Soo
Department of Pathology, Severance Hospital, Yonsei University College of Medicine Seoul, Republic of Korea.
Department of Gynecology and Obstetrics, Pusan National University Yangsan Hospital, Pusan National University School of Medicine Yangsan, Republic of Korea.
Int J Clin Exp Pathol. 2015 Jul 1;8(7):7998-8007. eCollection 2015.
Squash smear cytology of Langerhans cell histiocytosis (LCH) has rarely been reported. We described squash cytological findings of cranial LCH. Additionally, based on recent data that suggests an association of LCH with either viral infection or genetic alteration, we investigated the presence of several viruses or mutation of TP53 and BRAF in LCH tissue samples. Intraoperative squash smears of a small tissue fragment excised from the lesion demonstrated a mixed population of eosinophils, neutrophils, small lymphocytes and a high content of histiocytes. The histiocytes possessed abundant dense cytoplasm with round cell shape and eccentrically located nuclei with fine chromatin, delicate nuclear membranes and prominent nuclear grooves, indentations and pseudoinclusions. The cytologic features were consistent with Langerhans cells (LCs). Subsequent histopathologic examination confirmed the diagnosis of LCH. Immunohistochemically, the LCs were positive for S-100, CD1a and langerin, but negative for adenovirus, CMV, EBV, HHV-8, HPV, HSV, SV 40 and p53. BRAF V600E mutation was absent. Our findings did not support the role of viruses and genetic abnormalities in the pathogenesis of LCH. In summary, the presence of a mixed population of inflammatory cells and a high content of histiocytes with characteristic cytomorphology, along with radiologic evidence and appropriate clinical findings, is highly suggestive of LCH on the intraoperative squash smears. Awareness of characteristic cytological features of LCH is necessary for rapid and accurate diagnosis. Squash smear cytology is a potentially useful tool in the intraoperative diagnosis of LCH.
朗格汉斯细胞组织细胞增多症（LCH）的压片细胞学检查鲜有报道。我们描述了颅骨LCH的压片细胞学检查结果。此外，基于近期提示LCH与病毒感染或基因改变有关的数据，我们研究了LCH组织样本中几种病毒的存在情况以及TP53和BRAF的突变情况。从病变部位切除的一小块组织的术中压片显示有嗜酸性粒细胞、中性粒细胞、小淋巴细胞混合群体以及高含量的组织细胞。这些组织细胞具有丰富的致密细胞质，细胞呈圆形，细胞核偏位，染色质细腻，核膜薄，有明显的核沟、凹陷和假包涵体。细胞学特征与朗格汉斯细胞（LCs）一致。随后的组织病理学检查证实了LCH的诊断。免疫组织化学检查显示，LCs对S-100、CD1a和朗格素呈阳性，但对腺病毒、巨细胞病毒、EB病毒、HHV-8、人乳头瘤病毒、单纯疱疹病毒、SV 40和p53呈阴性。未发现BRAF V600E突变。我们的研究结果不支持病毒和基因异常在LCH发病机制中的作用。总之，术中压片上出现炎性细胞混合群体以及具有特征性细胞形态的高含量组织细胞，再加上影像学证据和适当的临床发现，强烈提示为LCH。了解LCH的特征性细胞学特征对于快速准确诊断至关重要。压片细胞学检查是LCH术中诊断的一种潜在有用工具。
