A case of grade1 follicular lymphoma diagnosed by laparoscopic lymph node resection: differentiating from late lymph node recurrence of endometrial cancer.

Follicular lymphoma is a common hematologic malignancy; however, it is less common among all malignant diseases and is difficult to suspect in advance due to the lack of specific clinical findings. Here, we report a case in which a late recurrence of corpus cancer was first suspected and finally diagnosed as follicular lymphoma. A 67-year-old female presented to our department with enlarged pelvic lymph nodes. She was diagnosed with breast cancer (HER2-posiotive with lymph node metastasis) and corpus cancer (endometrioid carcinoma grade 2, stage IA) 16 years prior, received definitive therapy and was followed up. A positron emission tomography scan was performed, and an accumulation of 18F-fluorodeoxyglucose (FDG) was detected in multiple lymph nodes, including the lymph nodes with no change in size or enlargement. We performed laparoscopic resection of the enlarged and FDG-accumulated lymph nodes and a pathological examination. The patient was diagnosed with follicular lymphoma (FL) grade 1 and is currently under observation at the Department of Hematology. FL can be considered when there is a discrepancy between the change in lymph node size and the degree of FDG accumulation. A pathological examination is useful for accurate diagnosis. Therefore, it is important to consider tissue collection; however, care must be taken to minimize the invasiveness of the procedure for the patient.