Department of Radiology, Nagoya City University Hospital, Nagoya, Japan.
Department of Pathology, Nagoya City University Hospital, Nagoya, Japan.
Dentomaxillofac Radiol. 2021 Oct 1;50(7):20200603. doi: 10.1259/dmfr.20200603. Epub 2021 Apr 20.
Salivary duct carcinoma is an aggressive tumour commonly showing local invasion and/or nerve palsy. However, their CT/MRI findings, especially, regarding T2WI, and the diffusion-weighted-image (DWI), were not well known. In this study, we correlated the CT/MRI appearance and the pathological findings containing the nerve invasion cases such as a facial nerve.
We reviewed 14 cases of SDC (parotid = 11, submandibular = 2, minor salivary gland = 1) pathologically proven peripheral nerve involvement. Their CT findings of all patient including dynamic contrast-enhancement study､MRI ( = 9) and DWI ( = 6) were also analyzed with histopathological correlation.
On contrast-enhanced CT, the solid component was moderately enhanced. On MRI, T2WI central low signal core ( = 6) with peripheral high intensity rim ( = 5) was frequently observed except heterogeneous low and high ( = 1), diffuse low ( = 1), and high ( = 1) signal cases. The hyaline degenerative area located in the tumour core was poorly enhanced. Eleven tumours had an ill-defined margin, reflecting invasive tumour growth. On DWI, they showed high signal [the central low and peripherally high ( = 4), and diffuse ( = 1), heterogeneously high signal ( = 1)]. The mean ADC value was 1.148 ~ 0.961 x 10-3 mm/s. With pathological correlation, the central low signal area on T2WI reflected hyaline degeneration. The sites of gross nerve involvement were revealed as tubular or branching structures on CE-CT ( = 3), and MRI ( = 1).
(1) We frequently observed a central low signal area on T2WI/DWI in SDC. With histopathological correlation, it corresponded to the central hyaline degeneration with the peripheral viable tumour. 2) The gross nerve involvement might be detected as a strongly enhancement structure.
涎腺导管癌是一种侵袭性肿瘤，常表现为局部侵犯和/或神经瘫痪。然而，其 CT/MRI 表现，特别是 T2WI 和弥散加权成像（DWI）的表现尚不清楚。本研究中，我们将 CT/MRI 表现与包含面神经等神经侵犯病例的病理发现相关联。
我们回顾了 14 例经病理证实的涎腺导管癌（腮腺=11 例，颌下腺=2 例，小唾液腺=1 例）患者的 CT 表现，包括动态增强研究、MRI（=9 例）和 DWI（=6 例），并结合组织病理学进行了分析。
在增强 CT 上，实性成分呈中度增强。在 MRI 上，T2WI 中央低信号核心（=6 例）伴外周高信号环（=5 例）较常见，除异质性低和高信号（=1 例）、弥漫性低信号（=1 例）和高信号（=1 例）外。肿瘤核心内的透明变性区强化程度较差。11 例肿瘤边界不清，反映出肿瘤的侵袭性生长。在 DWI 上，它们呈高信号[中央低信号伴外周高信号（=4 例），弥漫性（=1 例），异质性高信号（=1 例）]。平均 ADC 值为 1.148~0.961×10-3mm/s。与病理相关性分析，T2WI 上的中央低信号区反映了透明变性。大体神经受累的部位在 CE-CT（=3 例）和 MRI（=1 例）上显示为管状或分支结构。
（1）我们在涎腺导管癌中经常观察到 T2WI/DWI 上的中央低信号区。与组织病理学相关性分析，该区域对应于中央透明变性伴外周存活肿瘤。（2）大体神经受累可能表现为强化结构。
