Plasmocitoma extramedular em bulbo peniano de cão: relato de caso

Abstract

Non-cutaneous extramedullary plasmacytomas are relatively rare in dogs, affecting mainly the oral cavity and bowel loops. The involvement of the penile bulb has not been described, a fact of great importance for obstetric and veterinary oncology. The aim of this case report is to describe the occurrence of plasmacytoma in a dog's penile bulb, classified as a non-cutaneous extramedullary disease of rare location and unpublished casuistry. A non castrated dog of undefined breed, with seven years of age and weighing 15kg, presented clinical history of anorexia, vomiting, anuria and constipation. By specific examination of the external genitalia, a penile bulb mass was found in the preputial inspection, which was adhered to the encapsulated skin, extremely firm and rounded, measuring approximately 6 cm in diameter. By ultrasound evaluation of the structure in the penile bulb an increase of regional volume with heterogeneous echotexture and mixed echogenicity and tissue neovascularization upon color Doppler was observed. Incisional biopsy of the mass was performed and showed the presence of neoplasia of round cells. The characterization of the tumor was performed by immunohistochemistry and the neoplastic immuno cells were expressed CD79a and MUM1, indicating the diagnosis of extramedullary plasmacytoma. Although the penile tumors in dogs are predominantly transmissible venereal tumors (TVT) and plasmocytomas are rare neoplasms in this location, this case report provides a novel occurrence of extramedullary plasmacytoma in the penile bulb of a dog, a condition not yet described in veterinary. Keywords

Metastatic extramedullary plasmacytoma in a canine

“…Oncological disorders related to plasma cells, as described in veterinary medicine, encompass a group of diseases with highly variable clinical behavior. According to recent literature on hematopoietic tumors, clonal neoplastic disorders of plasma cells include multiple myeloma (MM), solitary bone plasmacytoma (POS), extramedullary plasmacytoma (EMP), and less commonly reported Waldenström's macroglobulinemia and plasma cell leukemia (6,11,16) .…”

“…Extramedullary plasmacytoma represents approximately 2.5% of neoplasms diagnosed in dogs (2,3) . It has been reported in the oral cavity, trachea, esophagus, stomach, intestine, skin (2,4) , spine (4) , penile bulb, mucosa (6,7) , as well as renal (8) and pulmonary (9) manifestations. Metastasis associated with more than one organ is considered uncommon.…”

Plasmocitoma extramedular metastático em um canino

“…As desordens oncológicas relacionadas aos plasmócitos descritas na medicina veterinária compreendem um grupo de doenças com comportamento clínico muito variável. Conforme literatura recente sobre tumores hematopoiéticos, os distúrbios neoplásicos clonais de plasmócitos incluem o mieloma múltiplo (MM), plasmocitoma ósseo solitário (POS), plasmocitoma extramedular (PEM), e menos comumente relatada a macroglobulinemia de Waldenström e a leucemia plasmocitária (6,11,16) .…”

“…Sendo relatadas na cavidade oral, traqueia, esôfago, estômago, intestino e pele (2,4) . Como também na coluna vertebral (4) , bulbo e mucosa peniana (6,7) , além da manifestação renal (8) e pulmonar (9) . A ocorrência da associação de metástase para mais de um órgão é considerada incomum, havendo apenas um relato de um canino com plasmocitoma extramedular em cólon e reto com a metastização para linfonodo e baço (10) .…”