title: Fine-needle aspiration diagnosis of an intraosseous amyloidoma.
abstract: Fine-needle aspiration (FNA) is frequently used as the initial diagnostic procedure for the investigation of bone and soft tissue masses. The majority of the lesions detected will represent metastatic carcinoma. Amyloid is a rare cause of a bone mass, with less than 15 published reports describing amyloid deposition within bone. The majority of reported cases involve the vertebral column. We report the finding of a massive amyloidoma of the iliac wing in a 46-year-old man. FNA smears and cell block preparations demonstrated fragments of waxy acellular material misinterpreted as necrotic debris. Subsequent open biopsy established the diagnosis of amyloid with congo red staining demonstrating apple green birefringence. Subsequent workup disclosed the patient to have anemia, hypogammaglobulinemia and trace monoclonal light chain gammopathy. Bone marrow examination revealed CD138a positive lambda restricted plasma cells consistent with plasma cell dyscrasia. Careful attention to the staining characteristics of amyloid in FNA derived material should allow the diagnosis of amyloidoma.
authors.affiliation: Departments of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Factor
authors.forename: Lester J
authors.initials: LJ
authors.lastname: Layfield
authors.forename: Allie H
authors.initials: AH
authors.lastname: Grossmann
authors.forename: Julia R
authors.initials: JR
authors.lastname: Crim
authors.forename: Shawn L
authors.initials: SL
authors.lastname: Price
authors.forename: R L
authors.initials: RL
authors.lastname: Randall
mesh_terms: D000682:Amyloid; D000686:Amyloidosis / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D044963:Biopsy, Fine-Needle; D001859:Bone Neoplasms / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000473:pathology*; D002449:Cell Aggregation; D015743:Giant Cells, Foreign-Body / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010950:Plasma Cells / Q000473:pathology; D014057:Tomography, X-Ray Computed
chemical_list: D000682:Amyloid