Clinical characteristics and outcome of dogs with presumed primary renal lymphoma

Abstract

Objectives To characterise the presentation, clinicopathologic data and outcome of 29 dogs with presumed primary renal lymphoma. Materials and Methods Retrospective analysis of medical records of dogs with suspected primary renal lymphoma from 11 institutions. Results All dogs were substage b, and lethargy and gastrointestinal signs were common presenting complaints, as were azotaemia (n=25; 86%) and erythrocytosis (n=15; 51%) on biochemical testing. Ultrasonography typically revealed bilateral renal lesions (n=23; 79%), renomegaly (n=22; 76%) and abdominal lymphadenopathy (n=14; 48%). Chemotherapy was the only treatment in 23 dogs, of which 11 responded, all considered partial responses. For all dogs the median progression‐free survival and median overall survival times were 10 days (range: 1 to 126) and 12 days (range: 1 to 212), respectively, and for dogs that responded to chemotherapy 41 days (range: 10 to 126) and 47 days (range: 10 to 212), respectively. Clinical Significance Primary renal lymphoma in dogs appears to be associated with a poor prognosis and short‐lived response to chemotherapy.

Imaging features of unilateral renal T‐cell lymphoma occurring simultaneously in the urinary bladder wall and contralateral ureter with secondary polycythaemia in a dog

“…6 In the present case, there was a slight increase of EPO, most likely due to the presence of the renal neoplasia. 2,6 For decades, abdominal ultrasound has been one of the main diagnostic tools to evaluate the kidneys when abnormalities in the renal architecture are suspected. Several studies have reported that the sonographic findings in dogs with renal lymphoma include renomegaly, hypoechoic lesions, pyelectasia and bilateral involvement; however, in our patient the sonographic appearance was that of a heterogeneous masstype lesion that distorted the normal renal morphology, rather than hypoechoic nodules.…”

“…In agreement with the case described by Froment and Gara‐Boivin in 2015, it was very likely that the erythrocytosis observed in our patient was an inappropriate secondary type, since, although arterial blood gas analysis was not performed, the patient presented a normal cardiovascular examination, not supporting systemic hypoxia. Secondary polycythaemia due to inappropriately elevated EPO is an infrequent paraneoplastic syndrome associated with infiltrative renal neoplasia 2, 6 . The increase in EPO production has been explained by two possible mechanisms, either the neoplastic cells are the ones that generate the ectopic production of EPO or an EPO‐like substance, or the neoplastic infiltration produces compression of the renal tissue and vascular supply causing local renal hypoxia that would originate a physiologically‐induced EPO production from hypoxic renal cells 6 .…”

“…Several studies have reported that the sonographic findings in dogs with renal lymphoma include renomegaly, hypoechoic lesions, pyelectasia and bilateral involvement; however, in our patient the sonographic appearance was that of a heterogeneous mass‐type lesion that distorted the normal renal morphology, rather than hypoechoic nodules. The use of other techniques is a nonspecific requirement to reach the diagnosis; 2, 11, 16 however, in dogs weighing greater than 25 kg, patient factors such as body size, amount of intraperitoneal fat and interference from gas artifact in the gastrointestinal tract can affect the quality and detail of the images acquired 17 . Multi‐phase contrast‐enhanced CT is used in dogs to assess pathologies affecting the kidney 18 while in humans, in addition to CT, MRI is also used for the evaluation of renal tumours in order to reduce the incidence of complications that may appear after a renal biopsy 19 .…”

“…Lymphoma is a common haematopoietic neoplasm in dogs and cats that often occurs in multicentric, gastrointestinal, mediastinal and cutaneous forms, with the primary extranodal presentation being less frequent 1 . The prevalence of primary renal lymphoma is unknown in dogs, and a small number of cases have been sporadically published in the veterinary literature 2 . On the other hand, lymphoma of the urinary tract involving the kidney, ureter and bladder is a very rare presentation in dogs and humans, described in very few cases 3, 4…”

“…3,4 Different canine renal tumours such as carcinomas, sarcomas and lymphomas have been found to be associated with non-primary erythrocytosis 5 ; moreover, in a recent study with a population of twenty-nine dogs with presumed primary renal lymphoma, secondary polycythaemia was observed in 51% of cases. 2 This type of polycythaemia is due to an increase in the production of erythropoietin (EPO) or an EPO-like substance, in the absence of systemic hypoxia, which could be originated by both benign and malignant disorders. 5 According to the reviewed literature, only a reduced number of cases of renal lymphoma combined with secondary erythrocytosis have been reported in dogs.…”