title: Cutaneous lymphoplasmacytic lymphoma with systemic metastasis in a cat.
abstract: A lymphoplasmacytic lymphoma was diagnosed in a 12- year-old domestic cat that had a primary cutaneous mass involving the stomach, liver, kidneys, heart, abdominal wall, diaphragm, bone marrow and several lymph nodes. Histopathologically, the most characteristic feature of this tumor was the heterogeneity of cell components, such as small lymphocytes, well-differentiated plasma cells and plasmacytoid transformed lymphocytes. Amyloid was deposited in the skin, stomach, and several lymph nodes. Immunohistochemically, neoplastic small lymphocytes were positive for CD20, and well-differentiated plasma cells and plasmacytoid transformed lymphocytes were positive for λ-Ig light chains and MUM1/IRF-4. These results emphasize the importance of lymphoplasmacytic lymphoma as a differential diagnosis of extramedullary cutaneous plasmacytoma in cats.
authors.affiliation: North Lab, 2–10 Atsubetsu-Nishi 2–4 Atsubetsu-ku, Sapporo 004–0062, Japan. northlab@d4.dion.ne.jp
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Kagawa
authors.forename: Tokiaki
authors.initials: T
authors.lastname: Yamashita
authors.forename: Shigeki
authors.initials: S
authors.lastname: Maetani
authors.forename: Yuko
authors.initials: Y
authors.lastname: Aoki
authors.forename: Kanako
authors.initials: K
authors.lastname: Sakaguchi
authors.forename: Kazuko
authors.initials: K
authors.lastname: Hirayama
authors.forename: Takashi
authors.initials: T
authors.lastname: Umemura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Taniyama
mesh_terms: D000818:Animals; D002415:Cats; D017809:Fatal Outcome; D005770:Gastrointestinal Neoplasms / Q000556:secondary / Q000662:veterinary*; D006338:Heart Neoplasms / Q000556:secondary / Q000662:veterinary*; D007680:Kidney Neoplasms / Q000556:secondary / Q000662:veterinary*; D008223:Lymphoma / Q000145:classification / Q000473:pathology / Q000662:veterinary*; D008297:Male; D019042:Muscle Neoplasms / Q000556:secondary / Q000662:veterinary*; D012878:Skin Neoplasms / Q000473:pathology / Q000662:veterinary*