The presence of a micropapillary component predicts aggressive behaviour in early and advanced gastric adenocarcinomas

Aims: A micropapillary component (MC) consists of small tight clusters of tumour cells surrounded by clear spaces resembling lymphatic tumour emboli. Carcinoma with a MC has recently been described as a highly aggressive variant. However, little is known about the clinicopathological significance of the MC in gastric adenocarcinoma. Methods: We investigated the clinicopathological characteristics of gastric adenocarcinoma with a MC and compared them with those of conventional gastric adenocarcinoma. Results: Among 172 cases, 23 (13.4) cases had a MC. The amount of micropapillary growth pattern in entire tumour areas ranged from 10 to 80. The presence of a MC in gastric adenocarcinoma was significantly associated with the depth of invasion, lymph node metastasis, lymphovascular invasion, perineural invasion, higher clinical stages, and poor overall survival rates, but not with age, gender, tumour size, location, and Lauren histological types. The MC was present in four (4.7) of 86 early gastric cancers and all but one of the early gastric cancers with a MC showed lymph node metastasis (p0.02). Conclusions: Recognition of a MC in early and advanced gastric adenocarcinomas is very important as it can predict cancer invasion and metastasis leading to a poor clinical outcome.