Fang Wu¹, Chun-hong Hu¹, Xue Wang²

¹Department of Oncology, The Second Xiangya Hospital of Central South University, ²Special medical department, Cancer Hospital Chinese Academy of Medical Sciences

Objective:We experienced a rare case of quadruple squamous cell carcinoma of the gut mucosa and skin after allogeneic hematopoietic stem-cell transplantation for Leukemia. Try to find pathogenesis for this case, and provide reference for diagnosis and treatment on similar cases as well as for relevant researches in the future. Method: Detect gene mutation of P53, EGFR, KRAS and BRAF in free tumor cells of the patient's periphera lblood by DHPLC. Conduct gene sequence for P53, EGFR, KRAS, BRAF and make analysis on MSI. Meanwhile, examine expression of proteins on P53 and EGFR of tumor cells by IHC. Adopt flow cytometry to detect T-lymphocyte subsets of the patient's peripheral blood. Result: P53 gene mutation was found in the detection of free tumor cell and tumor issue for the patient, other genes were not found to have clinical mutation, while EGFR and P53 showed high-level expression in all tumor tissues. Almost all tumor tissues of the patient presented lower or higher MSI. And the analysis of T-lymphocyte subsets indicated that the patient's immunologic function was weak. Conclusion: Mutation of tumor suppressor gene P53 may be the main cause of the secondary and multiple tumors after transplantation for this case. EGFR protein expressed high-level, which lead to the rise of MAPK pathway activation, playing an important part in the tumors, Existence of instable MSI(+) after Allo-HSCT indicated the instability of genome, which maybe lay the foundation for other gene mutations.

Key Words: hematopoietic cell transplantation (HSCT)