背景:唾液腺病变对细针抽吸(FNA)材料具有诊断挑战。它们相对不常见,然而存在广泛的细胞形态学。在这里,我们回顾了常见的唾液腺肿瘤,它们的细胞形态学特征,他们的诊断陷阱,和辅助研究有助于实现准确的诊断。
结论:良性和恶性唾液腺实体之间存在许多细胞形态重叠。此外,化生,囊性改变,和退行性变化是增加诊断困境的常见发现。这些复杂因素会导致唾液腺病变发生恶性肿瘤的微小风险,这些恶性肿瘤在FNA上被解释为良性。在极少数情况下,由于许多细胞形态重叠,即使是恶性唾液腺肿瘤也被误认为是良性的。例如,包含间质的良性和恶性肿瘤,如肌上皮瘤和腺样囊性癌,可能被误解为多形性腺瘤。此外,具有基底细胞特征的唾液腺肿瘤的诊断可能会混淆FNA材料;例如,基底细胞腺瘤可被误解为腺样囊性癌。粘液表皮样癌由于粘蛋白的含量不同,在吸入的物质上有许多不同的表现,核异型的程度,细胞内容,鳞状上皮化生.Acinic细胞癌在FNA上表现出具有丰富细胞质的大细胞,这可能被误认为是嗜酸细胞瘤或Warthin肿瘤中的嗜酸细胞。唾液腺癌表现出明显的恶性肿瘤特征,因此可能被误认为是涉及唾液腺的继发性肿瘤或其他恶性唾液腺肿瘤。肿瘤相关淋巴细胞的存在是误诊的另一个根本原因,尤其是在考虑颈动脉内淋巴结的鉴别诊断时。诸如免疫组织化学和分子研究之类的辅助研究正在获得对FNA病例的更多关注。PLAG1免疫染色,CD117,DOG1,乳腺珠蛋白,和雄激素受体(AR)是诊断唾液腺病变的常用免疫染色的例子。MYB基因融合,MAML2基因重排,和ERBB2/HER2是可用于诊断唾液腺肿瘤的分子改变的实例。总之,唾液腺细胞学的目的是区分良性实体和恶性实体,并防止不必要的积极治疗。
结论:唾液腺细胞学的诊断缺陷是巨大的。熟悉不同实体的细胞形态学及其细胞形态学重叠,辅助研究的应用提高了诊断率,患者管理和防止不必要的积极程序。
BACKGROUND: Salivary gland lesions possess diagnostic challenges on fine-needle aspiration (FNA) material. They are relatively uncommon, yet present with a wide spectrum of cytomorphology. Herein, we review common salivary gland neoplasms, their cytomorphologic features, their diagnostic pitfalls, and ancillary studies helpful in achieving an accurate diagnosis.
CONCLUSIONS: There are many cytomorphologic overlaps between benign and malignant salivary gland entities. Moreover, metaplasia, cystic changes, and degenerative changes are common findings adding to diagnostic dilemmas. These complicating factors contribute to a minute risk of malignancy in salivary gland lesions that are interpreted as benign on FNA. In rare cases, even malignant salivary gland neoplasms are misinterpreted as benign on aspirated material due to the many cytomorphologic overlaps. For example, benign and malignant neoplasms containing stroma such as myoepithelioma and adenoid cystic carcinoma may be misinterpreted as pleomorphic adenoma. Moreover, diagnosis of salivary gland neoplasms with basal cell features can be confusing on FNA materials; for example, basal cell adenoma can be misinterpreted as adenoid cystic carcinoma. Mucoepidermoid carcinomas have many different appearances on aspirated material due to variable amounts of mucin, degree of nuclear atypia, cellular content, and squamous metaplasia. Acinic cell carcinoma exhibits large cells with abundant cytoplasm on FNA, which can be mistaken for oncocytic cells in oncocytoma or Warthin tumor. Salivary duct carcinoma shows distinct features of malignancy and thus can be mistaken for secondary tumors involving the salivary glands or other malignant salivary gland tumors. The presence of tumor-associated lymphocytes is another underlying cause of misdiagnosis, especially when considering the differential diagnosis of an intraparotid lymph node. Ancillary studies such as immunohistochemistry and molecular studies are gaining more attention to be utilized on FNA cases. PLAG1 immunostaining, CD117, DOG1, mammaglobin, and androgen receptor (AR) are examples of commonly used immunostains in diagnosis of salivary gland lesions. MYB gene fusion, rearrangements of the MAML2 gene, and ERBB2/HER2 are examples of molecular alterations useful in diagnosis of salivary gland neoplasms. In conclusion, the aim of salivary gland cytology is to differentiate benign entities from the malignant ones and to prevent unnecessary aggressive treatments.
CONCLUSIONS: The diagnostic pitfalls are enormous in salivary gland cytology. Familiarity with cytomorphology of different entities and their cytomorphologic overlaps, and application of ancillary studies improves the diagnostic yield, patient management and prevents unnecessary aggressive procedures.