title: Localized muscle wasting as an initial symptom of skeletal muscle lymphoma.
abstract: A 25-year-old man who developed painless muscle wasting and weakness of only the right thigh, was eventually shown to have systemic lymphoma with muscle infiltration. The patient was initially misdiagnosed as focal inflammatory myopathy, and he had a partial response to steroid therapy. Immunohistochemical analysis of the biopsied muscle and the subcutaneous tumor revealed the infiltrating cells with a positive macrophage-associated marker (CD68) and negative T- or B-cell-associated antigens, leading to the final diagnosis of true histiocytic lymphoma. Although skeletal muscle lymphoma is extremely rare, it should be considered in the differential diagnosis of localized muscle wasting.
authors.affiliation: Third Department of Internal Medicine, Oita Medical University, Hasama-machi, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Ueyama
authors.forename: T
authors.initials: T
authors.lastname: Kumamoto
authors.forename: M
authors.initials: M
authors.lastname: Johno
authors.forename: S
authors.initials: S
authors.lastname: Mita
authors.forename: T
authors.initials: T
authors.lastname: Tsuda
mesh_terms: D000328:Adult; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D003937:Diagnosis, Differential; D006801:Humans; D007150:Immunohistochemistry; D016403:Lymphoma, Large B-Cell, Diffuse / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology; D008297:Male; D019042:Muscle Neoplasms / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology; D018908:Muscle Weakness / Q000473:pathology; D018482:Muscle, Skeletal / Q000473:pathology*; D009133:Muscular Atrophy / Q000473:pathology; D009220:Myositis / Q000175:diagnosis / Q000188:drug therapy; D011239:Prednisolone / Q000627:therapeutic use; D013848:Thigh
chemical_list: D000893:Anti-Inflammatory Agents; D018931:Antineoplastic Agents, Hormonal; D011239:Prednisolone