Cutaneous Non-Epitheliotropic Lymphoma Affecting the Abdominal Wall in Dog: A Case Report
A. Alves; L.M.C. Conti; C.H.T. Mathias; K.D. Oliveira; F.M. Machado; P.A. Ribeiro; L.R. Signorelli; V.K. Arruda
Veterinary Medicine Course, University Center of Vila Velha, Espírito Santo, Brazil
Cutaneus lymphoma is subdivided in epitheliotropic and non-epitheliotropic, representing three to eight percent of all tegumentary neoplasms in canines. The etiology is multifactorial and generally afflicts six to 12 year old animals. Boxer, Basset Hound, Cocker Spaniel, Saint Bernard, Irish Setter, German Shepard, Scottish Terrier and Golden Retriever are the most predisposed breeds to the non-epitheliotropic form, which originates from the B lymphocyte and presents itself as diffuse infiltrations of the dermis and subcutaneous by atypical lymphocytes. However the epidermis usually does not suffer any invasion. Frequently firm nodes and dermic or subcutaneous plates can be observed, in a lower incidence, exfoliative dermatitis, and in rare cases pruritus and oral involvement. The non-epitheliotropic lymphomas rarely lead to paraneoplastic syndrome. For the final diagnosis histopathologic and/or cytologic exams are required confirming the atypical lymphocytes. The treatment in most cases is unsuccessful, occurring remission in short term. A male dog, six year old Schnauzer, was attended at the Veterinary Hospital "Professor Ricardo Alexandre Hippler" at the University Center of Vila Velha, presenting a history of abdominal pain and dyschezia for about 2 days. Physical exams showed abdominal distension and rigidity with pain sensibility at palpation. Ultrasound showed increased thickness of the abdominal wall with heterogeneous echotexture. Aspirative cytology guided by ultrasound showed a predominance of large and medium lymphocytes with rare small nucleus, moderate to high nucleus/cytoplasm ratio, highly hyperchromatic nucleus with lumpy chromatin and eventually one or two visible nucleolus confirming highly malignant cutaneous non lymphoma. Thorax radiography showed no lung metastasis. The administration of vincristine, L-asparaginase, prednisone, cyclophosphamide and doxorubicin was prescribed for a period of 25 weeks according to Wisconsin Madison Protocol. Prechemotherapy hemogram, urinalysis, renal and hepatic biochemistry, electrocardiogram and echocardiography exams presented no alterations. Two days after the first session of chemotherapy there was a significant reduction of the abdominal distension and rigidity with the complete disappearance of pain. After seven days no more alterations were observed on the abdominal wall at ultrasound. On the second week of chemotherapy, cyclophosphamide was used and the animal began showing dysuria, stranguria, periuria and pollakiuria. Microscopic hematuria was observed at urinalysis and negative results in urine culture indicated sterile hemorrhagic cystitis. The cyclophosphamide was replaced by chlorambucil. Bladder infusion was done using dimethyl sulfoxide solution (DMSO) at 20%. The animal is on the seventh week of chemotherapy with complete remission of the lymphoma until now and in a good overall health.