Mira Loma High School, Sacramento, CA, U.S.A.
Department of Otolaryngology-Head and Neck Surgery, Kaiser Permanente Sacramento Medical Center, Sacramento, CA, U.S.A.
Anticancer Res. 2023 Feb;43(2):939-942. doi: 10.21873/anticanres.16238.
The clear-cell variant of mucoepidermoid carcinoma (MEC) involving minor salivary glands is extremely rare in children.
We report a case of clear-cell variant MEC in the minor salivary gland in a 10-year-old boy who presented with a mass of the right hard palate. Fine-needle aspiration showed features suggestive of clear-cell variant of MEC. Microscopically, the tumor cells showed predominant clear cells and scattered mucous cells. There was increased mitotic activity (6/mm). No tumor necrosis or nuclear pleomorphism was identified. The tumor cells were positive for cytokeratin 7 (CK7), tumor protein p63, P40 (ΔNp63), CK5/6 and mucicarmine. Rearrangement of mastermind-like transcriptional coactivator 2 (MAML2) (11q21) gene was present in the tumor cells by fluorescence in situ hybridization, supporting the diagnosis of an intermediate-grade clear-cell variant of MEC. A right infrastructure maxillectomy for palate carcinoma with negative margins was performed. Grossly, the tumor was a 2.1 cm well-circumscribed, friable, pale tan mass with focal areas of cystic change. The final pathological diagnosis was clear-cell variant of MEC, intermediate grade, pT2. Post surgery, the patient recovered and was doing well, with no tumor recurrence or metastasis at the 6-month follow-up.
To the best of our knowledge, this is the first documented case of clear-cell variant MEC in a child. Due to low to intermediate tumor grade, an overtly aggressive treatment should be avoided in a child.
涉及小唾液腺的黏液表皮样癌（MEC）透明细胞变体在儿童中极为罕见。
我们报告了一例 10 岁男孩右硬腭肿块中小唾液腺透明细胞变体 MEC。细针抽吸显示出 MEC 透明细胞变体的特征。显微镜下，肿瘤细胞显示出主要的透明细胞和散在的黏液细胞。有较高的有丝分裂活性（6/平方毫米）。未见肿瘤坏死或核异型性。肿瘤细胞对细胞角蛋白 7（CK7）、肿瘤蛋白 p63、P40（ΔNp63）、CK5/6 和粘卡红呈阳性。荧光原位杂交显示肿瘤细胞中存在主脑样转录共激活因子 2（MAML2）（11q21）基因重排，支持中间级透明细胞变体 MEC 的诊断。为了治疗 palate 癌，进行了右侧基础设施上颌骨切除术，切缘阴性。大体上，肿瘤为 2.1 厘米界限清楚、易碎、淡棕褐色肿块，伴有局灶性囊性变。最终的病理诊断为中间级别的透明细胞变体 MEC，pT2。手术后，患者恢复良好，无肿瘤复发或转移，随访 6 个月。
据我们所知，这是首例儿童透明细胞变体 MEC 的病例。由于肿瘤分级较低至中等，儿童应避免过度激进的治疗。
