Transformation of follicular lymphoma to double-hit lymphoma during adjuvant chemotherapy for concurrent ovarian carcinoma.

The frequency of multiple primary malignant neoplasms (MPMN) is increasing due to population aging. Since consensus guidelines for the treatment of MPMN are lacking, treatment strategies are determined by disease status on a per-patient basis. In this report, we describe a case of MPMN with follicular lymphoma (FL) grade 1 that transformed to double-hit lymphoma during adjuvant chemotherapy for concurrent ovarian carcinoma. A 64-year-old woman was diagnosed with MPMN of FL and endometrioid carcinoma by staging laparotomy and lymph node biopsy. She received four cycles of adjuvant chemotherapy (carboplatin and paclitaxel) for endometrioid carcinoma, but during chemotherapy, the FL grade 1 transformed to double-hit lymphoma. We speculate that adjuvant chemotherapy for endometrioid carcinoma may have triggered the transformation of FL in the present case.