Background/aims: Our aim was to investigate clinicopathological characteristics of a medullary cancer infiltration with scanty stroma type (por1) and a diffuse cancer infiltration with scirrhous stroma type (por2) of poorly differentiated gastric adenocarcinoma, especially differences in lavage cytodiagnosis, lymph node metastasis pattern and nuclear DNA ploidy between them.
Methodology: Age and gender of 168 patients (46: por1, 122: por2) and clinicopathological characteristics such as tumor site, lymph node metastasis, vascular invasion and serosal involvement were compared. Lymph node metastasis patterns were classified into 1) marginal, 2) nodular, 3) diffuse, and 4) massive types. The whole abdominal cavity was intra-operatively washed with 200 ml of saline, Papanicolaou-stained and used for lavage cytodiagnosis. Nuclear DNA ploidy pattern of carcinoma was determined using flow cytometry.
Results: Lymph node metastasis rate was significantly higher in por2, especially in those with positive serosal invasion. Positive rate of lavage cytodiagnosis was significantly higher in por2 (38.9%), than that in por1 (9.1%). There were more hematogeneous recurrences in por1 more peritoneal disseminated recurrences in por2. Survival rate was better in por1.
Conclusions: There were differences in lymph node metastasis, lavage cytodiagnosis and recurrence pattern between por1 and por2 even in poorly differentiated adenocarcinoma. These characteristics should be understood when selecting post-operative chemotherapy and also during follow-up.