Long-term production of pre-existing alloantibodies to E and c after allogenic BMT in a patient with aplastic anemia resulting in delayed hemolytic anemia.

Background: Delayed hemolysis mediated by long-term production of pre-existing recipient-derived antibodies directed against donor RBC antigens after allogenic BMT is an unusual complication of hematopoietic transplantation.

Case Report: A 26-year-old man with aplastic anemia had pre-existing alloantibodies to E and c. He received BMT from a donor, whose Rh phenotype was E+, c+.

Precancerous foci in pleomorphic adenoma of the salivary gland: recognition of focal carcinoma and atypical tumor cells by P53 immunohistochemistry.

Background: It is still controversial if atypical tumor cells scattered in salivary pleomorphic adenomas are precancerous and how carcinoma arises in pleomorphic adenomas.

Methods: We studied clinicopathologically the frequency and variation of cellular atypia among tumor cells and examined the expression status of p53 gene products as well as proliferating cell nuclear antigen (PCNA) in 101 surgical materials of pleomorphic adenomas.

Results: Histopathologically, atypical tumor cells were found in 51% of the cases examined.