Department of Radiology, Kinki University School of Medicine, Osakasayama-city, Osaka, Japan.
Br J Radiol. 2012 Jun;85(1014):709-13. doi: 10.1259/bjr/55639432. Epub 2011 Sep 6.
The aim of this study was to correlate the MRI appearance and pathological findings in each grade of the mucoepidermoid carcinoma (MEC) of the parotid gland.
We reviewed surgically proven MECs of parotid glands in 20 patients. Pathologically, 5 tumours were high-grade, 3 were intermediate and 12 were low-grade. MR images were evaluated with emphasis on signal intensities on T(2) weighted images, margin characteristics and lymph node metastasis, correlating these with pathological features.
Among the high-grade MECs, four out of five tumours showed inhomogeneous low to intermediate signal intensity on T(2) weighted images, reflecting high cellularity. All tumours had an ill-defined margin, reflecting invasive tumour growth. Among the intermediate-grade MECs, all three tumours showed intermediate signal intensity on T(2) weighted images and two tumours had an ill-defined margin. Among the low-grade MECs, 11 of the 12 tumours had a hyperintense area on T(2) weighted images because of the existence of abundant mucin secreting cells. Seven tumours had an ill-defined margin, reflecting peritumoural inflammatory changes rather than invasive tumour growth. Lymph node metastasis was seen in three high-grade MECs.
MECs of the parotid gland show variable MRI findings reflecting their histological nature, which seems to have certain tendencies depending on the tumour grade.
本研究旨在探讨腮腺黏液表皮样癌（MEC）各分级的 MRI 表现与病理结果的相关性。
我们回顾了 20 例经手术证实的腮腺 MEC 患者。病理上，5 例为高级别，3 例为中级别，12 例为低级别。重点评估了 T2 加权图像上的信号强度、边缘特征和淋巴结转移，并将其与病理特征相关联。
在高级别 MEC 中，5 例中有 4 例在 T2 加权图像上呈现不均匀的低到中等信号强度，反映出高细胞性。所有肿瘤均边界不清，反映出侵袭性肿瘤生长。在中级别 MEC 中，3 例均表现出中等信号强度，2 例边界不清。在低级别 MEC 中，12 例中有 11 例在 T2 加权图像上呈现高信号强度区域，因为存在丰富的黏液分泌细胞。7 例边界不清，反映出肿瘤周围炎症改变而不是侵袭性肿瘤生长。3 例高级别 MEC 发生淋巴结转移。
腮腺 MEC 的 MRI 表现具有多样性，反映了其组织学性质，似乎与肿瘤分级有一定的相关性。
