title: Follicular dendritic cell tumor as an unknown primary tumor.
abstract: A 70-year-old Japanese man presented to our hospital with a 1-month history of progressive general fatigue and anorexia. A physical examination revealed severe anemic condition, mild persistent splenomegaly, and no palpable surface lymph nodes. He had pleural effusion and ascites, though no malignant cells were detected in the effusion. He eventually died without any diagnosis of his disease. Immunohistochemical staining of his tumor after autopsy showed atypical cells that were negative for epithelial membrane antigen (EMA), keratin (AE1/3), keratin-20, vimentin, factor VIII, leukocyte common antigen (LCA/T200; CD45), myeloperoxidase (MPO), terminal deoxynucleotidyl transferase (TdT), lysozyme, CD1a, CD3, CD4, CD10, CD15, CD20 (L26), CD21, CD23, CD34, CD43, CD56, CD68, CD79a, CD138, and EBER-1 in situ. Only a few scattered cells expressed CD30, but they showed no staining for anaplastic large-cell lymphoma kinase (ALK). A few scattered cells expressed S-100 antigen and the majority of cells dominantly expressed dendritic cell-associated antigens (CD35, FDC, Ki-M1p). In conclusion, we found this unknown primary tumor to be consistent with a follicular dendritic cell tumor with anaplastic features.
authors: Department of Bioregulatory Medicine, Ehime University Graduate School of Medicine, Tohon-shi, Ehime 791-0295, Japan. yoshiyak@m.ehime-u.ac.jp
authors: Yoshihiro
authors: Y
authors: Yakushijin
authors: Hisaharu
authors: H
authors: Shikata
authors: Katsumi
authors: K
authors: Kito
authors: Kohichi
authors: K
authors: Ohshima
authors: Kensuke
authors: K
authors: Kojima
authors: Takaaki
authors: T
authors: Hato
authors: Hitoshi
authors: H
authors: Hasegawa
authors: Masaki
authors: M
authors: Yasukawa
mesh_terms: D000368:Aged; D001344:Autopsy; D014408:Biomarkers, Tumor / Q000032:analysis; D020566:Dendritic Cells, Follicular / Q000737:chemistry / Q000473:pathology*; D017809:Fatal Outcome; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000737:chemistry / Q000556:secondary*; D008207:Lymphatic Metastasis; D008297:Male; D009382:Neoplasms, Unknown Primary / Q000737:chemistry / Q000473:pathology*; D012509:Sarcoma / Q000737:chemistry / Q000556:secondary*; D013160:Splenic Neoplasms / Q000737:chemistry / Q000556:secondary
chemical_list: D014408:Biomarkers, Tumor