Differences in clinicopathological characteristics and computed tomography findings between signet ring cell carcinoma and nonsignet ring cell carcinoma in early and advanced gastric cancer

Abstract

Signet ring cell carcinoma (SRC) of the stomach is a histological type based on microscopic characteristics. SRC's clinicopathological characteristics and prognosis are still controversial. Our study is to describe the clinicopathological features and multidetector computed tomography (MDCT) findings of patients with SRC of the stomach in comparison with nonsignet ring cell adenocarcinoma (NSRC). We retrospectively analyzed data from 241 patients who had undergone curative gastrectomy, including 62 SRC and 179 NSRC. Clinicopathological outcomes and MDCT findings were evaluated, and we investigated whether these variables were correlated with histopathological type. In early gastric carcinoma, patients with SRC were younger (50.2 vs. 60.2 years; P = 0.000) and more likely to be observed in the middle and lower third stomach (P = 0.010). Early SRC had a tendency to be confined to the mucosa (82.1%). There were significant differences in degree of enhancement between early SRC and NSRC on MDCT imaging (P < 0.001). In advanced gastric carcinoma, SRC was more likely to be stage T3-4 (100%). SRC patients had thicker tumors (P = 0.001) and a higher frequency of diffusely infiltrative gross appearance (P < 0.001). SRC was more likely to have high-degree contrast enhancement than were NSRC (P = 0.001). The maximal diameter of SRC tumor on MDCT imaging correlated with lymph node metastasis (sensitivity 93.9%, specificity 74.1%) and serosal invasion (sensitivity 89.5%, specificity 78.0%) of SRC. In conclusion, SRC differs significantly from NSRC in clinicopathological features at presentation. MDCT could help differentiate advanced gastric SRC from NSRC based on the thickened stomach wall, high-degree contrast enhancement, and a higher frequency of diffusely infiltrative gross appearance, particularly in combination.

Contrast-enhanced computed tomography images of advanced gastric carcinoma. (A, B) Two contrast enhanced CT images in different patients with advanced SRC. Contrast enhanced CT scan shows diffuse gastric wall thickening with strongly enhancement. The layered and heterogeneous-enhancement pattern is shown. (C) Endoscopic image (same patient in B) of the lesion shows a diffusely infiltrating lesion. (D–F) Fifty-five-year-old man with NSRC. Contrast enhanced CT scan and coronal reconstruction show focal gastric wall thickening mainly of the enhancing thickened inner layer (arrow). The homogeneous-enhancement pattern is shown. Endoscopic image of the lesion shows an ulcer lesion located in the gastric antrum.

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