Iliac lymphadenectomy following intrauterine mapping in a female dog with breast neoplasm

ABSTRACT

Background: The lymphatic system plays an important role in the local control of neoplasms as well as in the transportation of tumor cells, which represents the most common pathway of metastasis. From the tumorigenesis, there is a remarkable enlargement of the tumor drainage network towards the regional and target lymph nodes. Since the mammary lymphatic system of animals with neoplasms as well as the demarcation of the pelvic and abdominal caudal chain are poorly studied, the aim of the present study is to report a case of iliac lymphadenectomy after intrauterine lymphatic dyeing in a dog with breast neoplasm, which allowed the identification of metastasis in the medial iliac lymph node.Case A 7-year-old, 13.4 kg, non neutered, mixed breed, female dog was diagnosed with ulcerative neoplasm in the left caudal abdominal breast, which presented evolution of approximately 90 days, presenting ulceration for 10 days, according to the tutor. After a clinical evaluation, thoracic radiography and abdominal ultrasonography were requested, which did not present metastasis suggestive images. Therefore, left unilateral total mastectomy was indicated. Retro-umbilical celiotomy was performed for the administration of 0.5 mL of 1% intrauterine methylene blue (body of the uterus), which allowed lymphatic mapping and medial iliac lymphadenectomy. Subsequently, ovariohysterectomy was performed and after celiorrhaphy, axillary lymphadenectomy was performed, followed by left unilateral mastectomy and concomitant removal of the superficial inguinal lymph node. The patient had a prompt recovery and was discharged from hospital in six hours postoperatively. The excised material was referred for histopathological examination, which revealed the presence of metastasis of simple tubulopapillary carcinoma of the mammary gland in the left medial and superficial inguinal lymph nodes, while the axillary lymph node had no metastases.[...]