What is your diagnosis? Vertebral mass in a cat Antonio Mel  endez-Lazo , Carlos Ros, Cristian de la Fuente, Sonia A~ nor, Francisco Fern andez-Flores, Josep Pastor Departament de Medicina i Cirug  ıa Animals, Universitat Aut onoma de Barcelona, Barcelona, Spain Correspondence A. Mel endez-Lazo, Servei d’Hematolog  ıa Cl  ınica Veterin aria, Departament de Medicina i Cirug  ıa Animals, Facultat de Veterin aria, Edifici V, Campus UAB, Bellaterra (Cerdanyola del Valles), Barcelona 08193, Spain E-mail: melendezlazovcp@gmail.com DOI:10.1111/vcp.12437 Case Presentation An 18-month-old neutered male Persian cat was referred to the Hospital Clinic Veterinari of the Universitat Aut onoma de Barcelona (HCV-UAB) for an investigation of a 4-week his- tory of progressive paraparesis. Physical examination was considered normal. Neurologic examination was consistent with a T3-L3 myelopathy. Marked thoracolumbar pain was present. Main differential diagnoses included inflammatory/ infectious disease and neoplasia. Hematology and complete serum biochemistry profiles and an abdominal ultrasono- graphic examination were unremarkable; feline immunode- ficiency virus/feline leukemia virus (FeLV) serologic tests were negative. Thoracic radiographs revealed a radiolucent lesion affecting T11-T13 vertebral bodies. Postmyelographic computed tomography revealed a marked thickening of the pedicle, lamina, and vertebral body of T13 and L1 vertebrae causing spinal cord compression on the left side (Figure 1). A T13-L1 left-side hemilaminectomy was performed in order to decompress the spinal cord and obtain a sample for analysis. Excisional biopsy of the proliferative lesion and intraopera- tive cytologic imprints were submitted for evaluation (Figure 2). Figure 1. Transverse computed tomographic image at the level of T13 vertebra in a young cat with progressive paraparesis. Note the marked thickening of the pedicle, lamina, and vertebral body on the left side causing spinal cord compression (arrow). Figure 2. Imprint of an extradural vertebral mass from a young cat with progressive paraparesis. Modified Wright stain. 1 Vet Clin Pathol 0/0 (2017) 1–2 ©2017 American Society for Veterinary Clinical Pathology Veterinary Clinical Pathology ISSN 0275-6382