Diagnosis of renal lymphoma by Wright-Giemsa-stained cytocentrifuged urine evaluation in a cat.

Lymphoma represents up to 30% of neoplasms diagnosed in cats. Diagnosis of lymphoma in the urinary system by examination of urine sediment has been described in a dog, but apparently not previously in cats. Concurrent samples of serum, EDTA whole blood, and urine were submitted from a 15-year-old spayed female domestic shorthair cat exhibiting weight loss, polyuria, and polydipsia. Hematology and biochemical abnormalities included a mild normocytic, normochromic, non-regenerative anemia; an inflammatory leukogram; and azotemia. Urinalysis evaluation revealed inadequate urine concentration and marked proteinuria. Wet-mount urine sediment examination revealed moderate numbers of leukocytes and erythrocytes. A uniform population of intermediate-to-large lymphocytes was observed on a fresh, Wright-Giemsa-stained preparation from cytocentrifuged urine. The cat was euthanized and necropsy was completed. Bilateral renomegaly was identified and characterized by multifocal, pale-yellow, coalescing, poorly defined, homogenous nodules. Microscopically, these nodules were composed of dense sheets of CD3-positive round cells, consistent with T-cell renal lymphoma. Key clinical message: Lymphoma is a common neoplasm in cats that can affect many organ systems, including the upper urinary tract. This case represents an uncommon method of identifying neoplastic lymphocytes via evaluation of cytocentrifuged urine, and emphasizes the benefits of examining Romanowsky-stained urine sediment in animals.

Diagnostic du lymphome rénal chez un chat par évaluation d'urine cytocentrifugée avec coloration Wright-Giemsa. Le lymphome représente jusqu'à 30 % des néoplasmes diagnostiqués chez le chat. Le diagnostic d'un lymphome du système urinaire par examen des sédiments urinaires a été décrit chez un chien, mais apparemment pas à ce jour chez le chat. Des échantillons simultanés de sérum, de sang total dans un tube avec EDTA et d'urine ont été soumis provenant d'une chatte domestique à poils courts stérilisée de 15 ans présentant une perte de poids, une polyurie et une polydipsie. Les anomalies hématologiques et biochimiques comprenaient une légère anémie normocytaire, normochrome et non régénérative; une formule leucocytaire inflammatoire; et une azotémie. L'analyse d'urine a révélé une concentration urinaire insuffisante et une protéinurie marquée. L'examen microscopique des sédiments urinaires a révélé un nombre modéré de leucocytes et d'érythrocytes. Une population uniforme de lymphocytes de taille intermédiaire à grande a été observée sur une préparation fraîche colorée au Wright-Giemsa à partir d'urine cytocentrifugée. Le chat a été euthanasié et une autopsie a été réalisée. Une rénomégalie bilatérale a été identifiée et caractérisée par des nodules multifocaux, jaune pâle, coalescents, mal définis et homogènes. Au microscope, ces nodules étaient composés de feuilles denses de cellules rondes CD3-positives, compatibles avec un lymphome rénal à cellules T.Message clinique clé :Le lymphome est une tumeur courante chez le chat qui peut affecter de nombreux systèmes organiques, y compris les voies urinaires supérieures. Ce cas représente une méthode rare d'identification des lymphocytes néoplasiques via l'évaluation de l'urine cytocentrifugée et met l'emphase sur les avantages de l'examen des sédiments urinaires avec coloration de Romanowsky chez les animaux.(Traduit par Dr Serge Messier).

Constitutive secretion of soluble interleukin-2 receptor by human T cell lymphoma xenografted into SCID mice. Correlation of tumor volume with concentration of tumor-derived soluble interleukin-2 receptor in body fluids of the host mice.

Increased serum concentration of soluble alpha-chain receptor for interleukin-2 (sIL-2R) has been noted in patients with a variety of inflammatory conditions and lymphoid malignancies including T cell leukemia and lymphoma. Elevated sIL-2R serum levels seen in lymphoid malignancies appear to correlate with the clinical stage of disease. However, because sIL-2R is produced by normal activated lymphocytes, it has been uncertain whether serum sIL-2R in such conditions is derived from tumor cells or normal immune cells responding to the tumor. To address this question, we used a model of human (CD30+) anaplastic, large T cell lymphoma transplanted into immunodeficient SCID mice. Reverse transcription polymerase chain reaction of tumor RNA showed that the tumor, designated mJB6, contains mRNA for alpha-chain of human IL-2R. Furthermore, 15 to 25% of tumor cells stained with anti-human IL-2R alpha-chain mAb. Solid phase ELISA analysis of serum samples from mice bearing mJB6 lymphoma showed high concentrations of human sIL-2R. None of the control mice without lymphoma or with human nonlymphoid tumors (prostatic carcinoma, ovarian carcinoma, and glioblastoma multiforme) showed detectable human sIL-2R. The sIL-2R serum titers of mJB6-bearing mice correlated strongly with tumor volume (P < 0.0001). Tumors as small as 0.4 to 0.8 mm3 could be detected by this method. The sensitivity of sIL-2R ELISA exceeded at least 150 times the sensitivity of conventional radioisotopic tumor detection. Total resection of mJB6 tumors resulted in complete clearance of sIL-2R from the murine serum within 48 hours with a half-life of 6 hours. Accordingly, partial resection led to a significant decrease in sIL-2R followed by gradual increase with tumor regrowth. sIL-2R was also detected in the urine of mJB6-transplanted mice. As in serum, urine concentrations of sIL-2R were proportional to tumor mass (P < 0.02). Based on these findings we postulate that malignant cells are a major source of serum sIL-2R in patients with lymphoid tumors. In addition, our data further support monitoring sIL-2R concentration in body fluids as a sensitive method to detect change in tumor volume in such patients.