title: Cytokeratin-positive fibroblastic reticular cell tumor with follicular dendritic cell features: a case report and review of the literature.
abstract: Fibroblastic reticular cell (FRC) neoplasms, which are one of the histiocyte tumor types, are very rare. Here we report a cytokeratin (CK)-positive FRC neoplasm having features of follicular dendritic cells in a 54-year-old woman with right axillary lymph node swelling. The resected lymph node showed multiple nodular aggregations simulating and replacing normal follicles. The tumor cells had a uniform, large and oval to polygonal shape, abundant cytoplasm, and various sizes of nuclei with central eosinophilic nucleoli and coarse nuclear chromatin. They were positive for CK AE1/AE3+CAM5.2, CK7, tenascin C, l-caldesomone, and CD21, weakly positive for S100, and negative for CD1a. Ultrastructurally, the tumor cells had long interdigitating microvillus-like cell processes and oval to elongated vesicular nuclei. In addition, the intercellular spaces contained accumulations of collagen, and some tumor cells had desmosomal-like junctions. These findings suggest that the present case is a CK-positive FRC tumor with follicular dendritic cell features.
authors.affiliation: Departments of *Hematology §Breast and Molecular Oncology, Gifu University Graduate School of Medicine †Department of Internal Medicine, Gihoku Kosei Hospital ‡Tokai Clinic, Gifu ∥Department of Pathology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences ¶Division of Pathophysiology, Okayama University Graduate School of Health Sciences, Okayama #Department of Diagnostic Pathology, Yamagata University Faculty of Medicine, Yamagata, Japan.
authors.forename: Naoe
authors.initials: N
authors.lastname: Goto
authors.forename: Hisashi
authors.initials: H
authors.lastname: Tsurumi
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Takami
authors.forename: Manabu
authors.initials: M
authors.lastname: Futamura
authors.forename: Kasumi
authors.initials: K
authors.lastname: Morimitsu
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Takata
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Sato
authors.forename: Tadashi
authors.initials: T
authors.lastname: Yoshino
authors.forename: Seiji
authors.initials: S
authors.lastname: Adachi
authors.forename: Koshiro
authors.initials: K
authors.lastname: Saito
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Yamakawa
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis* / Q000235:genetics; D001706:Biopsy; D020566:Dendritic Cells, Follicular / Q000737:chemistry / Q000648:ultrastructure; D005260:Female; D015620:Histiocytic Disorders, Malignant / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D007621:Karyotyping; D007633:Keratins / Q000032:analysis*; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000737:chemistry / Q000601:surgery / Q000648:ultrastructure; D008854:Microscopy, Electron; D008875:Middle Aged; D049268:Positron-Emission Tomography; D017154:Stromal Cells / Q000737:chemistry / Q000648:ultrastructure; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D007633:Keratins