Micropapillary component in gastric adenocarcinoma: an aggressive variant associated with poor prognosis

Abstract

Background Adenocarcinomas with a micropapillary component (MPC) have been described as an unusual morphological variant in various organs. However, few reports have described MPCs in gastric carcinomas, and the clinicopathological features of MPC are unclear. Methods Immunohistochemistry was used to detect the expression of epithelial membrane antigen, CK7, CK20, p53, epidermal growth factor receptor, b-catenin, c-erbB-2, and Ki-67. Correlation of the MPC to tumor stage, lymph node metastasis, and lymphovascular invasion was performed using Fisher's exact test. Kaplan-Meier estimates were used to analyze overall survival. Results Immunohistochemical staining demonstrated that micropapillary and conventional gastric carcinomas showed similar positivity rates for all markers. However, aberrant expression of E-cadherin was detected in the tumors with MPCs without immunoreactivity in the stroma face. Epithelial membrane antigen showed the characteristic inside-out staining pattern of MPCs. Lymphatic invasion (P = 0.003), venous invasion (P = 0.017), lymph node metastasis (P = 0.014), and tumor stage (P = 0.022) were significantly increased in patients with MPCs when compared with conventional adenocarcinomas. MPC subtype II had a significantly higher frequency of lymph node metastasis than subtype I (P = 0.014). However, the proportion of MPC was not associated with lymph node metastases (P = 0.136). Overall survival of patients with an MPC was significantly shorter than that of patients with conventional adenocarcinomas (P = 0.031). In addition, overall survival was significantly lower in patients with a subtype II MPC growth pattern than in those with subtype I MPC in gastric carcinomas (P = 0.040). Conclusion Gastric adenocarcinomas with MPC appear to be an aggressive variant associated with a poor prognosis. MPCs occurring in gastric adenocarcinomas should be included in surgical pathology reports, even if the proportion of MPC in the lesions is very low in the lesion.

Cervical carcinomas with a micropapillary component: a clinicopathological study of eight cases

“…Carcinomas showing a micropapillary growth pattern were first clearly documented in the breast, but have since been recognised in many other sites, including the lung, bladder, gastrointestinal tract, pancreaticobiliary tract, and salivary gland . Low‐grade serous carcinomas of the ovary also typically have a micropapillary appearance, and this may be a feature, usually focal, of high‐grade serous carcinomas .…”

Gastric carcinoma with an invasive micropapillary carcinoma component showing HER2 gene amplification and CD10 expression: A case report and review of the literature

“…Tumors with type II IMPC behave more aggressively, with higher risks of lymph node metastasis and worse prognosis . The percentage of IMPC component did not significantly affect the metastatic rate of lymph nodes and survival rate . In our case, the tumor contained type II IMPC component.…”

“…Two growth patterns have been reported for IMPC: IMPC nests within cystic spaces (type I), and IMPC nests admixed with bands of fibrous connective tissue (type II) . Tumors with type II IMPC behave more aggressively, with higher risks of lymph node metastasis and worse prognosis . The percentage of IMPC component did not significantly affect the metastatic rate of lymph nodes and survival rate .…”

“…Our case also shows MUC1 positivity of the IMPC component and vascular invasion was prominent. Two growth patterns have been reported for IMPC: IMPC nests within cystic spaces (type I), and IMPC nests admixed with bands of fibrous connective tissue (type II) . Tumors with type II IMPC behave more aggressively, with higher risks of lymph node metastasis and worse prognosis .…”

Practical Points in Gastric Pathology

“…26 Since the first identification of micropapillary carcinoma of the stomach, 27 subsequent studies [28][29][30][31][32][33] have demonstrated that gastric cancers (GCs) with an MPC component exhibit aggressive biological behavior, with frequent lymphatic invasion, extensive lymph node metastasis, and lower overall survival. This is similarly observed in other organs.…”