Spinal cord compression secondary to extramedullary hematopoiesis in a dog

Abstract

Case Description-An 11-year-old spayed female Siberian Husky was evaluated because of a 2-week history of progressive paraparesis.Clinical Findings-Results of neurologic examination were consistent with a T3-L3 myelopathy.There were no abnormalities on CBC, and hypercalcemia was noted on serumbiochemical analysis. Several hypoechoic splenic nodules were evident on abdominal ultrasonography,and results of fine-needle aspiration cytology were consistent with splenicextramedullary hematopoiesis (EMH). Two compressive, extradural masses in the dorsalepidural space of the thoracolumbar region of the spinal cord were seen on MRI images. Treatment and Outcome-A dorsal laminectomy was performed to remove the extraduralspinal masses. Results of histologic examination of tissue samples were consistent withEMH. Following surgery, clinical signs of paraparesis resolved, and there was no recurrenceof the masses 24 months after surgery.Clinical Relevance-Extramedullary hematopoesis should be considered as a differentialdiagnosis in dogs in which results of diagnostic imaging indicate a epidural mass. In humanpatients, spinal EMH usually occurs secondary to an underlying hematologic disease, butit can also occur spontaneously. Treatment options reported for humans include surgicaldecompression, radiation therapy, chemotherapy, and blood transfusion. The dog of this reportresponded favorably to surgical decompression and was clinically normal 2 years aftersurgery.