Hicks J, Flaitz C
Department of Pathology, Texas Children's Hospital and Baylor College of Medicine, MC1-2261, 6621 Fannin Street, Houston, TX 77030-2399, USA.
Oral Oncol. 2000 Sep;36(5):454-60. doi: 10.1016/s1368-8375(00)00033-6.
Malignant neoplasms represent one-third of all pediatric salivary gland tumors. Mucoepidermoid carcinoma (MEC) composes 51% of malignant tumors and 16% of all salivary gland neoplasms in pediatrics. Prognostic factors in MEC in pediatric patients have not been well defined. Histopathologic features, clinical outcomes and proliferation markers in 26 pediatric patients (median age 11 years; 19F:7M) with salivary gland MECs were evaluated retrospectively. MEC histocytologic grading used a three-tiered system. Proliferation was assessed by determining the percentage of tumor cells immunoreactive for PCNA and Ki-67. Tumor site was 16 parotid, eight submandibular, one base of tongue and one maxillary lip. Median tumor size was 2.5 cm (range 1.5-5 cm). MEC grade was nine low grade (LG), 15 intermediate grade (IG) and two high grade (HG). Metastatic disease and capsular invasion occurred in five cases, while perineural invasion was noted in three cases. Mean percentage of tumor cells immunoreactive for proliferation markers is as follows: PCNA: LG 9%, IG 17%, HG 32%; and Ki-67: LG 7%, IG 12%, HG 26%. Treatment was surgical in 21 cases, and surgery with chemotherapy and radiotherapy in five cases. Two patients with high grade MECs died of disease (21, 44 months). Twenty-four patients had no evidence of disease at a median follow-up of 104 months (range 30-298 months). MECs were second malignancies in two children with prior radiotherapy and chemotherapy for leukemia and histiocytosis. Low and intermediate grade salivary gland MECS in a pediatric population may have a favorable outcome when compared with high grade MECs. Proliferation markers appear to be linked to histocytologic MEC grade and may provide information regarding biologic behavior of salivary gland MECs in children and adolescents.
恶性肿瘤占所有儿童唾液腺肿瘤的三分之一。黏液表皮样癌（MEC）占儿童恶性肿瘤的51%，占所有唾液腺肿瘤的16%。儿科患者MEC的预后因素尚未明确界定。对26例唾液腺MEC患儿（中位年龄11岁；19例女性：7例男性）的组织病理学特征、临床结局和增殖标志物进行了回顾性评估。MEC组织细胞学分级采用三级系统。通过确定对PCNA和Ki-67免疫反应的肿瘤细胞百分比来评估增殖情况。肿瘤部位为16例腮腺、8例颌下腺、1例舌根和1例上颌唇。肿瘤中位大小为2.5 cm（范围1.5 - 5 cm）。MEC分级为9例低级别（LG）、15例中级别（IG）和2例高级别（HG）。5例发生转移和包膜侵犯，3例出现神经周围侵犯。对增殖标志物免疫反应的肿瘤细胞平均百分比如下：PCNA：LG为9%，IG为17%，HG为32%；Ki-67：LG为7%，IG为12%，HG为26%。21例采用手术治疗，5例采用手术联合化疗和放疗。2例高级别MEC患儿死于疾病（分别为21个月和44个月）。24例患者在中位随访104个月（范围30 - 298个月）时无疾病证据。在2例曾接受白血病和组织细胞增多症放疗及化疗的儿童中，MEC为第二原发恶性肿瘤。与高级别MEC相比，儿童低级别和中级别唾液腺MEC可能预后良好。增殖标志物似乎与MEC组织细胞学分级相关，可能为儿童和青少年唾液腺MEC的生物学行为提供信息。
