Perez-Ordonez B, Linkov I, Huvos A G
Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
Histopathology. 1998 Jun;32(6):521-9. doi: 10.1046/j.1365-2559.1998.t01-2-00410.x.
The diagnosis of polymorphous low-grade adenocarcinoma (PLGA) of salivary glands remains difficult for general surgical pathologists. In an effort to understand the morphological heterogeneity of these neoplasms and facilitate their recognition we reviewed the architectural patterns, cell differentiation and immunohistochemical features of 17 case of PLGA.
There were 11 females and six males with a mean age of 58 years. Twelve tumours were located in the palate, two in the posterior third of the tongue, and one each in the upper lip, buccal mucosa and retromolar triangle. Two patients presented with neck metastases. The mean tumour size was 20 mm (range 6-50 mm). The tumour cells were arranged in five architectural patterns: tubules and small duct-like structures; cords and trabeculae; solid nests; cribriform areas and papillae. Twelve (71%) cases were composed of a combination of tubules and small duct-like structures, cords and trabeculae, and solid nests. Cribriform areas with pseudoluminal spaces were seen in six (35%) cases. A focal papillary pattern was evident in three cases and constituted 40% of the tumour in one. Perineural invasion was seen in 13 cases (76%). All cases studied were positive for CAM5.2, 34BE12, vimentin and S100 protein and showed overexpression of bcl-2 protein. Rb protein was present in 13 cases whereas p53 expression was absent in all cases. The average proliferation index (PI) was 7% (range 1-17%). Three patients developed local recurrences with cervical lymph node metastases but no patient died as result of tumour. No morphological features were found to be prognostic for the development of local recurrences or lymph nodes metastases.
PLGA is a distinctive neoplasm of salivary glands formed by luminal and nonluminal tumour cells with limited patterns of architectural differentiation. The relative proportion of these cells seems to play a significant role in the morphogenesis of these tumours. The overexpression of the bcl-2 protein and the low PI suggest that inhibition of programmed cell death may be involved in the oncogenesis of PLGA.
对于普通外科病理学家而言，涎腺多形性低度恶性腺癌（PLGA）的诊断仍然困难。为了了解这些肿瘤的形态学异质性并便于识别，我们回顾了17例PLGA的结构模式、细胞分化及免疫组化特征。
11例女性，6例男性，平均年龄58岁。12个肿瘤位于腭部，2个位于舌后三分之一处，上唇、颊黏膜及磨牙后三角各1个。2例患者出现颈部转移。肿瘤平均大小为20mm（范围6 - 50mm）。肿瘤细胞排列成五种结构模式：小管和小导管样结构；条索和小梁；实性巢；筛状区和乳头。12例（71%）由小管和小导管样结构、条索和小梁以及实性巢组合构成。6例（35%）可见有假管腔间隙的筛状区。3例可见局灶性乳头模式，其中1例占肿瘤的40%。13例（76%）可见神经周围浸润。所有研究病例CAM5.2、34BE12、波形蛋白和S100蛋白均呈阳性，且bcl - 2蛋白呈过表达。13例存在Rb蛋白，而所有病例均无p53表达。平均增殖指数（PI）为7%（范围1 - 17%）。3例患者出现局部复发并伴有颈部淋巴结转移，但无患者因肿瘤死亡。未发现形态学特征对局部复发或淋巴结转移的发生具有预后意义。
PLGA是涎腺的一种独特肿瘤，由管腔和非管腔肿瘤细胞形成，结构分化模式有限。这些细胞的相对比例似乎在这些肿瘤的形态发生中起重要作用。bcl - 2蛋白的过表达和低PI提示程序性细胞死亡的抑制可能参与了PLGA的肿瘤发生。
