Dedifferentiation in adenoid cystic carcinoma of salivary gland - An uncommon complication associated with an accelerated clinical course
Dedifferentiation in adenoid cystic carcinoma of salivary gland - An uncommon complication associated with an accelerated clinical course
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DOI：
10.1097/00000478-199904000-00012
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发表时间：
1999-04-01
影响因子：
5.6
通讯作者：
Ngan, RKC
中科院分区：
文献类型：
--
作者：
Cheuk, W;Chan, JKC;Ngan, RKC
涎腺腺样囊性癌(ACC)通常是一种无痛性肿瘤，临床病程较长，有复发和晚期转移。作者报告了三例脱分化为高度恶性肿瘤的ACC。1例患者一开始就出现去分化的ACC，首发时伴有广泛的局部病变和多发的淋巴结转移，需要进行肢解手术。两名患者在切除最初无并发症的ACC后，分别在4年和10年出现去分化的ACC；两名患者在复发后1.5年内死亡。组织学上，去分化成分表现为明显的间变性细胞群，胞浆丰富，不规则形肿瘤岛状浸入促结缔组织间质，完全丧失ACC的双细胞分化特征。与ACC相比，免疫表型特征发生了改变，例如在两例被解释为低分化腺癌的病例中，获得了S100蛋白的强烈染色，并且缺乏肌上皮成分。1例为肉瘤样瘤，伴局灶性肌上皮病变。1例去分化癌组织中P53蛋白过度表达，2例细胞周期蛋白D1过度表达。去分化成分的Ki67指数高于ACC。据作者所知，这份报告首次记录了去分化是ACC中肿瘤进展的一种形式，这与危险的临床结果有关。
Adenoid cystic carcinoma (ACC) of the salivary gland is generally an indolent tumor that pursues a protracted clinical course with recurrences and late metastasis. The authors report three cases of ACC with dedifferentiation to high-grade malignant neoplasms. One patient developed dedifferentiated ACC ab initio, with extensive local disease and multiple lymph nodes metastases at first presentation, requiring mutilating surgery. Two patients had dedifferentiated ACC 4 and 10 years, respectively, following excision of the initial uncomplicated ACC; both patients died within 1.5 years after recurrence. Histologically, the dedifferentiated component appeared as a distinct population of anaplastic cells with more abundant cytoplasm, irregular-shaped tumor islands infiltrating a desmoplastic stroma, and total loss of bicellular differentiation characteristic of ACC. The immunophenotypic profile was altered in comparison with the ACC, such as acquisition of strong staining for S100 protein and lack of a myoepithelial component in the two cases that were interpreted as being poorly differentiated adenocarcinoma. One case was a sarcomatoid neoplasm with focal myoepithelial features. Overexpression of p53 protein was demonstrated in the dedifferentiated component in one case, and overexpression of cyclin D1 was seen in two cases. The dedifferentiated component had a higher Ki67 index than did the ACC. To the authors' best knowledge, this report represents the first documentation of dedifferentiation as a form of tumor progression in ACC, which is associated with a sinister clinical outcome.