title: What is your diagnosis? Shoulder mass in a dog with lameness.
abstract: An adult castrated male Golden Retriever of unknown age was presented with a history of weight loss and progressive left thoracic limb lameness. On physical examination, a solid mass was palpated on the left scapula that had areas of lysis on radiographs and an area of cortical bone loss on ultrasound. Hepatomegaly, abdominal distension, and numerous intra-abdominal soft tissue masses were also found. Fine-needle aspirates of the scapula and several abdominal masses contained numerous free nuclei mixed with fewer individualized, intact cells that were round in shape and rarely formed small sheets. The cells had high nuclear to cytoplasmic ratios, central nuclei, coarsely stippled chromatin, 1-2 prominent nucleoli, and basophilic cytoplasm with indistinct cell borders. The cytopathologic interpretation was neuroendocrine neoplasia, either metastatic or multicentric. The dog was subsequently euthanized and based on gross and histologic findings at necropsy, a diagnosis of pheochromocytoma with multiple metastases was made. The neoplastic cells stained positive with Grimelius stain and were immunoreactive for synaptophysin and chromogranin A. Pheochromocytomas are rare tumors in dogs and uncommonly undergo distant metastasis, especially to bone.
authors.affiliation: Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, VA, USA. kmboes@purdue.edu
authors.forename: Katie
authors.initials: K
authors.lastname: Boes
authors.forename: Kurt
authors.initials: K
authors.lastname: Zimmerman
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Saunders
authors.forename: Laurie
authors.initials: L
authors.lastname: O'Rourke
authors.forename: Natalie
authors.initials: N
authors.lastname: Crawford
authors.forename: Christopher
authors.initials: C
authors.lastname: Ober
authors.forename: Nicolaas
authors.initials: N
authors.lastname: Lambrechts
authors.forename: Jonathan
authors.initials: J
authors.lastname: Miller
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000473:pathology / Q000662:veterinary*; D000818:Animals; D001859:Bone Neoplasms / Q000556:secondary / Q000662:veterinary; D004283:Dog Diseases / Q000175:diagnosis / Q000473:pathology*; D004285:Dogs; D007680:Kidney Neoplasms / Q000556:secondary / Q000662:veterinary; D007794:Lameness, Animal; D008113:Liver Neoplasms / Q000556:secondary / Q000662:veterinary; D008175:Lung Neoplasms / Q000556:secondary / Q000662:veterinary; D008297:Male; D010190:Pancreatic Neoplasms / Q000556:secondary / Q000662:veterinary; D010673:Pheochromocytoma / Q000473:pathology / Q000662:veterinary*; D013160:Splenic Neoplasms / Q000556:secondary / Q000662:veterinary