title: Transformation of follicular lymphoma in the retroperitoneal muscles demonstrated by CT-guided needle biopsy of FDG-avid lesions; case series.
abstract: We herein report two cases of relapsed follicular lymphoma (FL) with transformation in the retroperitoneal muscles. Fluorodeoxyglucose (FDG)-positron emission tomography (PET) combined with computed tomography (CT) showed high uptakes in the retroperitoneal muscles. We considered excisional biopsy at first, since it is definitely the most reliable means to obtain histological diagnosis. However, excisional biopsy of the retroperitoneal muscles is challenging for anatomical reasons. Moreover, our patients were kept under poor performance status. Thus, CT-guided percutaneous needle biopsy of FDG-avid retroperitoneal muscles was performed. Histopathological examination of the biopsied specimens demonstrated proliferation of transformed large B cells in both cases. Sheets of large B cells were also recorded in one case. CT-guided needle biopsy is less prioritized than excisional biopsy because of limited information on tissue architecture and increasingly complicated WHO classification. Our series indicate that image-guided needle biopsy of FDG-avid lesions is sufficient for the diagnosis of transformation. Higher priority should be given to this method in the setting of transformed aggressive lymphoma.
authors.affiliation: Department of Hematology and Oncology, Graduate School of Medicine, The University of Tokyo Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Uni
authors.affiliation: Department of Hematology and Oncology, Graduate School of Medicine, The University of Tokyo Japan.
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Nakamura
authors.affiliation: Department of Hematology and Oncology, Graduate School of Medicine, The University of Tokyo Japan ; Department of Cell Therapy and Transplantation Medicine, The University of Tokyo Hospital Japan.
authors.forename: Akihide
authors.initials: A
authors.lastname: Yoshimi
authors.affiliation: Department of Pathology, Graduate School of Medicine, The University of Tokyo Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Shinozaki-Ushiku
authors.affiliation: Department of Pathology, Graduate School of Medicine, The University of Tokyo Japan.
authors.forename: Atsuko
authors.initials: A
authors.lastname: Hosoi
authors.affiliation: Department of Hematology and Oncology, Graduate School of Medicine, The University of Tokyo Japan.
authors.forename: Kumi
authors.initials: K
authors.lastname: Nakazaki
authors.affiliation: Department of Hematology and Oncology, Graduate School of Medicine, The University of Tokyo Japan.
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Nannya
authors.affiliation: Department of Pathology, Graduate School of Medicine, The University of Tokyo Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Fukayama
authors.affiliation: Department of Hematology and Oncology, Graduate School of Medicine, The University of Tokyo Japan ; Department of Cell Therapy and Transplantation Medicine, The University of Tokyo Hospital Japan.
authors.forename: Mineo
authors.initials: M
authors.lastname: Kurokawa
mesh_terms: D000368:Aged; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008224:Lymphoma, Follicular / Q000473:pathology*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000473:pathology*; D064847:Multimodal Imaging; D018482:Muscle, Skeletal / Q000473:pathology*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: CT-guided needle biopsy; FDG-avid; Follicular lymphoma; retroperitoneum; transformation