Molnar Stacy L, Zarka Matthew A, De Las Casas Luis E
Department of Pathology, The University of Toledo Medical Center, Toledo, OH, 43614.
Department of Laboratory Medicine and Pathology, Mayo Clinic, Scottsdale, AZ, 85259.
Diagn Cytopathol. 2016 May;44(5):422-5. doi: 10.1002/dc.23434. Epub 2016 Jan 22.
Epithelial-myoepithelial carcinoma (EMC) is a rare salivary gland malignancy with variable cytologic findings. Its rarity, variable morphologic findings, and similarities with more common salivary gland entities make it a difficult cytologic diagnosis. As the name signifies, the key feature of this tumor is presence of an epithelial and myoepithelial component. However, when one of these two components is scant on the fine needle aspiration (FNA) smears, it may be overlooked. We present a case from a 62 year-old female who presented to the clinic with a parotid nodule and episodes of sharp, throbbing pain. A fine needle aspiration was performed which revealed a highly cellular specimen comprised primarily of aggregates of cells with small, round nuclei and scant to absent cytoplasm. Abundant hyaline stromal material was also noted. The case was signed out as basaloid neoplasm with a recommendation for surgical resection. The subsequent resection specimen revealed EMC. By reviewing the FNA specimen following the surgical resection of the tumor, we were able to utilize the benefit of hindsight to more clearly identify the subtle, biphasic components of the tumor.
上皮-肌上皮癌（EMC）是一种罕见的涎腺恶性肿瘤，具有多样的细胞学表现。其罕见性、形态学表现多样以及与更常见涎腺病变的相似性使其在细胞学诊断上具有难度。顾名思义，该肿瘤的关键特征是存在上皮和肌上皮成分。然而，当这两种成分之一在细针穿刺（FNA）涂片上较少时，可能会被忽视。我们报告一例62岁女性病例，该患者因腮腺结节及突发锐痛、搏动性疼痛就诊。进行了细针穿刺，结果显示标本细胞丰富，主要由细胞核小而圆、胞质稀少或缺乏的细胞聚集体组成。还发现了大量透明间质物质。该病例诊断为基底样肿瘤，并建议手术切除。随后的切除标本显示为上皮-肌上皮癌。通过回顾肿瘤手术切除后的FNA标本，我们能够利用事后诸葛亮的优势更清晰地识别肿瘤细微的双相成分。
