Hrudka Jan, Drozenová Jana, Guha Anasuya, Chovanec Martin
Cesk Patol. 2020 Summer;56(3):172-176.
Adenoid cystic carcinoma (ACC) is one of the most common salivary gland malignancies. In rare cases, ACC undergoes high-grade transformation, which is associated with poor prognosis, in contrast to relatively long survival in the conventional ACC. Conventional ACC is characterized by typical histopathology showing glandular arrangement with sharply demarcated lumina, the tumor cells have sparse cytoplasm and angulated hyperchromatic nuclei. ACCs undergoing high-grade transformation lack these morphological features. In this paper we present a case of 46 years old female patient presenting with locally advanced tumor of the parotid gland and neck lymphadenopathy, coming for surgery. A suspect lymph node was sent to freeze section histology. Large non-cohesive cells with vesicular nuclei and prominent nucleoli along with well persevered lymph node architecture were seen in the frozen slide. This finding lead to suspicion of a lymphoma, the surgery finished in the extent of superficial parotidectomy and selective neck dissection of regions II-IV. Subsequent histopathological examination of formalin-fixed lymph node proofed epithelial nature of the atypical cells by p63 positivity. In the parotid gland resection specimen, an ACC with high-grade component was indentified. The high-grade ACC shared cell morphology with the lymph node metastasis. 17 from 20 lymph neck nodes contained metastases of high-grade ACC. Interestingly, there was strong CD117 expression in the high-grade ACC, whereas the conventional part was fully negative. To the best of our knowledge, the high-grade ACC of the parotid gland was reported only in 10 cases in the medical literature.
腺样囊性癌（ACC）是最常见的涎腺恶性肿瘤之一。在罕见情况下，ACC会发生高级别转化，这与预后不良相关，而传统ACC的生存期相对较长。传统ACC的特征是典型的组织病理学表现为腺管排列，管腔界限清晰，肿瘤细胞胞质稀少，核呈角形且深染。发生高级别转化的ACC缺乏这些形态学特征。本文报告一例46岁女性患者，因腮腺局部晚期肿瘤伴颈部淋巴结肿大前来手术。一个可疑淋巴结被送去做冰冻切片组织学检查。在冰冻切片中可见大的非黏附性细胞，核呈泡状，核仁明显，同时淋巴结结构保存完好。这一发现引发了对淋巴瘤的怀疑，手术范围为浅叶腮腺切除术及II-IV区选择性颈部淋巴结清扫术。随后对福尔马林固定的淋巴结进行组织病理学检查，通过p63阳性证实了非典型细胞的上皮性质。在腮腺切除标本中，发现了一个具有高级别成分的ACC。高级别ACC与淋巴结转移灶具有相同的细胞形态。20个颈部淋巴结中有17个含有高级别ACC转移灶。有趣的是，高级别ACC中CD117表达强烈，而传统部分则完全阴性。据我们所知，腮腺高级别ACC在医学文献中仅报道过10例。
