Disseminated histiocytic sarcoma in a Silky Terrier
Sanmarti, Enio E.
A 1-year-old male castrated Silky Terrier dog was presented to the Cornell University Emergency Service with a 2-week history of lameness and progressive stiffness. On physical examination, the patient was ambulatory but stiff with a stilted gait. He was hypertonic with multifocal, asymmetric soft tissue swellings and enlargement of the right antebrachium extensor muscles, right epaxial muscle, left oblique muscles, and left biceps femoris muscle. The cervical musculature was bilaterally swollen and hypertonic, and the patient had minimal range of motion of neck and was painful upon palpation. Pertinent results of a complete blood count included mild normocytic normochromic non-regenerative anemia, mild leukocytosis with a mature neutrophilia, and mild monocytosis. Results of a chemistry panel revealed low BUN and creatinine, mild hyperphosphotemia, moderate elevations in AST and GGT, moderately elevated creatine kinase, and mild hemolysis. Radiographs revealed moderate, multifocal, asymmetric soft tissue swellings with a subtle increase in opacity. MRI exam of the cervical spine revealed multifocal asymmetric myopathy, generalized lymphadenopathy, extradural compressive myelopathy of C5-7, and a questionable esophageal mass. EMG of the cervical muscles revealed a normal signal centrally within the muscle tissue and an abnormal signal in the periphery of the muscle. Cerebral spinal fluid (CSF) analysis showed a mild mononuclear pleocytosis. The patient’s CSF tested negative for Neospora (IFA), Canine Distemper Virus (PCR), and Toxoplasma (IgG/IgM). Serum was negative for Cryptococcus (Ag) and Rickettsia ristici (IFA) and 4DX Snap was negative for Borrelia burgdorferi, Erlichia canis, Anaplasma phagocytophilum, and Dirofilaria immitis. A skeletal muscle biopsy from the cervical region was composed of a poorly differentiated population of round pleomorphic cells which proved to be CD18 positive on immunohistological staining. The dog was ambulatory but his gait was stiff and began to regurgitate after feeding. The patient was discharged to the care of his owners on prednisone, clindamycin, doxycycline, tramadol, pregabalin, methocarbamol, and famotidine. The patient represented two weeks later for a scheduled euthanasia, as the clinical signs were worsening despite palliative therapy. Necropsy findings were consistent with disseminated histiocytic sarcoma with multifocal infiltration of the skeletal muscle, diaphragm, lymph nodes, esophagus and stomach.
Senior seminar paperSeminar SF610.1 2014
Dogs -- Diseases -- Case studies