Polycythemia and inappropriate erythropoietin concentrations in two dogs with renal T-cell lymphoma

Suspected renal interstitial cell tumor causing polycythemia in two dogs

Here we report a case series of two dogs diagnosed as renal interstitial cell tumor (RICT) accompanied by elevated serum erythropoietin level and marked polycythemia. RICT is a rare tumor in dogs, originating from renal interstitial cells. While several renal tumors such as renal lymphoma, adenocarcinoma, carcinoma, sarcoma, fibrosarcoma and nephroblastoma may cause polycythemia, polycythemia caused by RICT has never been reported in dogs. The tumors in both dogs were solitary and lied within cortex or cortico-medullary junction. Histopathology revealed spindle-shaped cells suggesting mesenchymal origin, with no mitotic figures suggesting that the tumors in both dogs were benign. Following surgical removal of the affected kidney, serum erythropoietin level and polycythemia normalized in both dogs.

Case Report: Diffuse Lumbar Hyperostosis Causing Vertebral Canal Stenosis in a Dog With Concurrent Multicentric T-Cell Lymphoma

A 4-year-old female spayed Bullmastiff-cross presented with a 24-h history of progressive paraparesis. Neurological examination was consistent with L4–S3 myelopathy. On magnetic resonance imaging (MRI), all vertebrae showed homogenously increased short tau inversion recovery (STIR) signal with strong contrast enhancement. The vertebral canal was concentrically narrowed along the length of the L5 vertebra secondary to bony proliferation of the vertebral pedicles, dorsal lamina, and vertebral body. Cytological analysis of the peripheral lymph nodes and subsequent flow cytometry was consistent with T-cell lymphoma. The dog was euthanised due to poor prognosis. Necropsy confirmed the presence of stage V multicentric T-cell lymphoma, as well as diffuse hyperostosis of the vertebral bodies. This is the first report of presumed paraneoplastic lumbar skeletal hyperostosis.

Bilateral Renal Large B Cell Lymphoma in a Dog: A Case Report and Review of the Literature

Canine lymphoma is a commonly reported neoplasia and, in most dogs, arises from lymph nodes before spreading to other organs. Renal lymphoma rarely occurs, and kidneys usually are a secondary site of origin. Primary renal lymphoma is infrequently described in the veterinary literature. In this study, we present a rare case of primary renal lymphoma in a dog and a review of similar cases. A 3-year-old male dog was admitted due to anorexia, weakness and vomiting. Clinical examination revealed bilaterally enlarged kidneys. Imaging demonstrated the presence of multiple renal masses. Cytology of abdominal fluid and kidneys led to the diagnosis of large cell lymphoma. Histopathology and immunohistochemistry on tissue samples taken from the kidneys confirmed the cytological diagnosis of lymphoma and categorized it as primary bilateral renal large B-cell lymphoma (LBCL).

A case of canine renal lymphoma of granular lymphocytes with severe polycythemia

BACKGROUND

Renal lymphoma in dogs is rare and has a poor prognosis. Granular lymphocyte morphology is rarely reported in canine renal lymphoma. Mild to moderate polycythemia is reported in a number of canine renal lymphoma cases.

CASE PRESENTATION

A 10-year-old Labrador retriever presented to a university veterinary teaching hospital after a 1-month history of polyuria, polydipsia, and pollakiuria and a 2-week history of abdominal distention, lethargy, and increased respiratory effort. Abdominal ultrasound showed a wedge-shaped to rounded, heterogeneously hypoechoic mass lesion in the left kidney. Cytologic analysis of a percutaneous aspirate of the mass was consistent with lymphoma of granular lymphocytes. Severe polycythemia (hematocrit 0.871) was noted on a complete blood cell count. Clonality analysis identified a clonally rearranged T-cell receptor (TCR) gene and immunohistochemical staining was CD3+, CD79a- and CD11d+, supporting cytotoxic T-cell lymphoma.

CONCLUSIONS

To our knowledge, this is the first report of renal cytotoxic T-cell lymphoma with severe polycythemia in a dog. Severe polycythemia and renal cytotoxic T-cell lymphoma are both rare in dogs; this report adds to the body of knowledge on these conditions.

Clinical characteristics and outcome of dogs with presumed primary renal lymphoma

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.

Inappropriate Secondary Erythrocytosis in a Dog With Renal Sarcoma

A 7-year-old mixed breed dog was evaluated for erythrocytosis with an initial hematocrit of 82.3%. Abdominal ultrasound revealed a 6 cm mass on the cranial pole of the right kidney. Daily therapeutic phlebotomies were performed, reducing the hematocrit to 54%. The dog underwent a right nephroureterectomy, recovered without complications, and was discharged 3 days after surgery. Histopathologic evaluation revealed a completely excised grade II soft tissue sarcoma. The preoperative erythropoietin level was 7.00 mU/mL (RI 1.90-22.90 mU/mL) and the 3-day postoperative erythropoietin level was 0.99 mU/mL, supporting a diagnosis of inappropriate secondary erythrocytosis due to the renal tumor. Secondary erythrocytosis resulting from renal soft tissue sarcoma is rare. Confirmatory testing with erythropoietin levels can assist in the diagnosis of secondary erythrocytosis. Erythropoietin levels that are normal or increased in the face of erythrocytosis indicate a source of inappropriate erythropoietin production.

Renal adenocarcinoma-associated erythrocytosis in a cat: clinicopathological features and immunohistochemical results

This report documents a case of secondary inappropriate erythrocytosis in a cat with renal cell adenocarcinoma, its stabilization through manual erythrocytapheresis, and the EPO-immunostaining on the affected kidney. An 11-year-old cat was presented with lethargy, weight loss and polyuria/polydipsia. An abdominal mass was detected upon physical examination. Clinicopathological work-up revealed marked erythrocytosis (HCT value 64.8%), renal azotemia and decreased urine specific gravity (USG). An abdominal ultrasound was performed, localizing the mass in the right kidney. Serum erythropoietin (EPO) was above the reference interval (RI), and the cytology of the mass was indicative of renal carcinoma. Manual erythrocytapheresis was performed in order to stabilize the patient before surgery, improving the cat’s clinical and clinicopathological condition. After nephrectomy, EPO and creatinine concentrations returned within the RI, while the USG markedly increased. Histopathology confirmed the diagnosis of renal adenocarcinoma. Immunohistochemistry with anti-EPO antibody revealed diffuse and strong cytoplasmatic positivity in tumor cells.

Expression of platelet-derived growth factor BB, erythropoietin and erythropoietin receptor in canine and feline osteosarcoma

The discovery of expression of the erythropoietin receptor (EPO-R) on neoplastic cells has led to concerns about the safety of treating anaemic cancer patients with EPO. In addition to its endocrine function, the receptor may play a role in tumour progression through an autocrine mechanism. In this study, the expression of EPO, EPO-R and platelet-derived growth factor BB (PDGF-BB) was analysed in five feline and 13 canine osteosarcomas using immunohistochemistry (IHC) and reverse transcription polymerase chain reaction (RT-PCR).

EPO expression was positive in all tumours by IHC, but EPO mRNA was only detected in 38% of the canine and 40% of the feline samples. EPO-R was expressed in all samples by quantitative RT-PCR (RT-qPCR) and IHC. EPO-R mRNA was expressed at higher levels in all feline tumours, tumour cell lines, and kidney when compared to canine tissues. PDGF-BB expression was variable by IHC, but mRNA was detected in all samples. To assess the functionality of the EPO-R on tumour cells, the proliferation of canine and feline osteosarcoma cell lines was evaluated after EPO administration using an alamarBlue assay and Ki67 immunostaining. All primary cell lines responded to EPO treatment in at least one of the performed assays, but the effect on proliferation was very low indicating only a weak responsiveness of EPO-R. In conclusion, since EPO and its receptor are expressed by canine and feline osteosarcomas, an autocrine or paracrine tumour progression mechanism cannot be excluded, although in vitro data suggest a minimal role of EPO-R in osteosarcoma cell proliferation.

Polycythemia, increased erythropoietin levels in a patient with renal lymphoma

A young male presented to our clinic with 3 months history of shortness of breathness and progressive distension of abdomen. On investigations, patient had renal failure, polycythemia and nephromegaly. A diagnosis of non-Hodgkin's lymphoma was made on renal and lymph node biopsy. Serum erythropoietin concentrations were physiologically inappropriate. – Erythropoietin immunohistochemistry on renal tissue samples demonstrated positive staining for tumor cells. This patient was managed as a case of infiltrative lymphoproliferative disorder with kidney involvement having polycythemia owing to paraneoplastic Erythropoietin production and possibly local hypoxia produced by tumor cells. With maximum efforts, we could not find such an association in the literature.

Ultrasonographic characteristics of canine renal lymphoma

There is little published information on the ultrasonographic appearance of canine renal lymphoma. The purpose of this retrospective study was to provide additional information regarding the ultrasonographic characteristics of canine renal lymphoma, suggest ultrasonographic description criteria, and evaluate the role of fine-needle aspirate cytology in the diagnosis of this disease. The ultrasonographic features of confirmed renal lymphoma were reviewed in ten dogs. Pyelectasia was found in all dogs. Other ultrasonographic findings were loss of corticomedullary distinction (9/10 dogs), renomegaly (8/10 dogs), renal deformity (6/10 dogs), hypoechoic lesion(s) (6/10 dogs), and hyperechoic lesion(s) (2/10 dogs). Hypoechoic lesions were described as masses, nodules, and indistinct areas. In 30% of the cases (3/10 dogs) ultrasound revealed only minor abnormalities, including grade 1 pyelectasia, mild renomegaly, and focal loss of corticomedullary definition. Bilateral lesions were seen in nine dogs (90%). Renal fine-needle aspirates were performed in 9/10 dogs, yielding a diagnosis in seven on first attempt (78%). Two dogs had been given a provisional cytological diagnosis of round cell neoplasia; in one dog lymphoma was confirmed by second aspirate and by tissue core biopsy in the other. In 1/10 dogs, lymphoma was found at necropsy. Findings indicated that ultrasonographic signs of canine renal lymphoma may be subtle, canine renal lymphoma should be included in the differential diagnosis when the above ultrasonographic features are observed, and fine-needle aspirate cytology is a useful method for diagnosing this disease.