title: Bone marrow involvement in follicular lymphoma: comparison of histology and flow cytometry as staging procedures.
abstract: Bone marrow (BM) examination is a routine staging procedure in follicular lymphoma (FL). Commonly, both BM histology as well as flow cytometry (FCM) of BM aspirates are performed. In order to compare the diagnostic value of these two techniques, we retrospectively evaluated trephine BM biopsies and listmode data of patients with a confirmed diagnosis of FL, obtained in parallel during a 5-year period. One hundred and thirty nine specimens from 91 patients with FL were eligible for analysis. After joint review, nine cases (6.5%) were reclassified, either in histology (six cases) or FCM (three cases). Seventy nine specimens (57%) showed no infiltration with both methods. Sixty specimens (43%) were scored positive for BM involvement by any of the two techniques. Concordant positive results were obtained in 41 cases (68% of positive BM). False negative results were obtained by FCM in 14 cases (23% of positive BM) and by histology in five cases (8%). Discrepant results between BM histology and FCM are frequent in patients with FL, most likely due to the predominantly paratrabecular infiltration and fibrosis typical for FL. Due to the lower false negative rate, trephine BM biopsy remains crucial for the detection of BM involvement in FL.
authors.affiliation: Department of Hematology and Oncology, Klinikum rechts der Isar, Technical University Munich, Ismaninger Strasse 22, 81675 Munich, Germany.
authors.forename: Burkhard
authors.initials: B
authors.lastname: Schmidt
authors.forename: Markus
authors.initials: M
authors.lastname: Kremer
authors.forename: Katharina
authors.initials: K
authors.lastname: Götze
authors.forename: Kristina
authors.initials: K
authors.lastname: John
authors.forename: Christian
authors.initials: C
authors.lastname: Peschel
authors.forename: Heinz
authors.initials: H
authors.lastname: Höfler
authors.forename: Falko
authors.initials: F
authors.lastname: Fend
mesh_terms: D001706:Biopsy; D001853:Bone Marrow / Q000473:pathology*; D001856:Bone Marrow Examination; D005434:Flow Cytometry / Q000592:standards*; D006801:Humans; D016130:Immunophenotyping; D008224:Lymphoma, Follicular / Q000175:diagnosis*; D009367:Neoplasm Staging