Comparison on MSCT and pathological findings of metastatic lymph nodes in pancreatic cancer patients

Abstract

Objective To discuss the MSCT imaging characteristics of metastatic lymph nodes in pancreatic cancer. Methods The MSCT images of 30 pancreatic cancer patients with metastatic lymph node confirmed by pathology were selected and all the patients underwent enhanced MSCT before surgery. The location, maximum short axis diameter (MSAD), sizes, density, enhancement, necrosis and fusion of the metastatic lymph nodes were analyzed using the 5th edition of TNM stage of Japan Pancreatic Society in 2002 as the standard. Results Sixty-three metastatic lymph nodes was pathologically diagnosed, while 53 were diagnosed by MSCT. The metastatic lymph nodes most commonly occurred in group 13 and 17 in pancreatic head cancer, while group 18 lymph node metastasis was more common in pancreatic body and tail cancer. The MSAD of metastatic lymph nodes was 2~17 mm with the average of (7.2±4.0)mm. All of metastatic lymph nodes were divided into MSAD<5 mm group, 5 mm~<10 mm group and ≥ 10 mm group based on their size. The number of metastatic lymph nodes of the three groups were 10, 18 and 25, respectively. The number of enhanced metastatic lymph nodes was decreased as the size increased, while the number of necrotic and fused lymph nodes was increased, which were statistically different (all P <0.05). Comparison between the two groups showed that the number of enhancement metastatic lymph nodes in MSAD<5 mm group and 5 mm~<10 mm group were more than that in ≥10 mm group(7/10 and 11/18 vs 2/25). The number of fused lymph nodes in MSAD<5 mm group and 5 mm~<10 mm group were less than that in ≥10 mm group (0 and 2/18 vs 22/25). Clear edge metastatic lymph nodes were more in MSAD<5 mm group than that in ≥10 mm group (6/10 vs 5/25). The number of necrotic metastatic lymph nodes in MSAD<5 mm group was less than that in ≥10 mm group(2/10 vs 18/25). All the differences above were statistically significant ( all P<0.05), but no other significant differences were found between two groups. Conclusions The main imaging findings of metastatic lymph nodes in pancreatic cancer were unobvious enhancement, intratumoral necrosis and fusion. Heterogeneous density and unclear edge could benefit the diagnosis of metastatic lymph node. Key words: Pancreatic neoplasms; Lymphatic, metastasis; Tomography, spiral computed