Veterinary clinical pathology最新文献

A 7-year-old female spayed Bernese Mountain dog was presented for evaluation of hematuria. Incidentally, a right stifle sarcoma was diagnosed via cytology, which raised concern for histiocytic sarcoma (given the patient's signalment) versus another joint-associated sarcoma. Histopathology and immunohistochemistry revealed a CD18-negative, non-histiocytic origin cell population. Findings were consistent with a joint-associated grade II soft tissue sarcoma (STS). The patient's hematuria was progressive over 5 months, and urinary bladder transitional cell carcinoma (TCC) was diagnosed via cystoscopy and histopathology. An enlarged right medial iliac lymph node was identified on routine restaging via abdominal ultrasound 3 months later. Cytology of the lymph node revealed a markedly pleomorphic cell population, again raising concern for histiocytic sarcoma (HS). Other differentials included an anaplastic metastatic population from the joint-associated STS or the TCC. Immunocytochemistry revealed a cytokeratin-positive, CD18-, CD204-, and vimentin-negative cell population, consistent with a carcinoma. DNA was extracted from cytology slides to sequence cells for BRAF mutation status. Sequencing revealed a homozygous V596E (transcript ENSCAFT00845055173.1) BRAF mutation, consistent with the known biology of TCC. In neither case was HS truly present in this patient, but immunocytochemistry provided information that helped to optimize the patient's chemotherapy recommendations.

A feline cutaneous melanocytic tumor in a 1-year-old cat is reported. The cytologic, histologic, and immunohistochemical characteristics of the pediatric feline cutaneous melanocytoma are included. A solitary, black-colored nodule on the head was histologically diagnosed as the epithelioid type of melanocytoma. Immunohistochemically, the neoplastic melanocytes demonstrated immunoreactivity to the S100 and MelanA antibodies but not to the PNL2 antibody. Despite high mitotic counts (17/10HPFs) and a Ki67 index (33%) suggesting malignant melanoma, the patient exhibited a favorable 5-month outcome. The mitotic activity of the neoplastic cells may not provide a reliable prediction for feline melanocytic tumors.

A 3-year-old male neutered domestic shorthair cat presented with lethargy, hyporexia, and pyrexia of unknown origin. Biochemical analysis using a Beckman Coulter AU480 demonstrated marked increases in creatine kinase and aspartate aminotransferase, indicative of severe muscle injury, with concurrent presumptive myoglobinuria on urinalysis. A marked, non-physiologic increase in measured bicarbonate and resultant negative anion gap was documented; however, calculated bicarbonate obtained via a point-of-care blood gas analyzer was within normal limits. Laboratory error due to interference by lactate dehydrogenase was suspected and supported by the results of subsequent biochemical testing. Artifactual increases in bicarbonate have been documented in cases of rhabdomyolysis in horses, cows, and a bird. However, to the best of the authors' knowledge, this is the first report to demonstrate this spurious change in a cat.

A 12-year-old spayed female Dalmatian presented with acute vomiting and anorexia. The clinicopathological and imaging abnormalities included icterus, biliary obstruction, and multiple diffuse splenic hypoechogenic nodules. Cholecystectomy was performed to remove the obstruction, followed by liver biopsy and splenectomy. Histopathological and immunohistology evaluation of the spleen, liver, and gallbladder revealed splenic marginal zone lymphoma (MZL) with gallbladder and hepatic infiltration of neoplastic CD20/CD79α-positive cells. Moreover, we observed clonal rearrangements of the immunoglobulin heavy-chain (IgH) gene in all three tissues. The dog was in good condition without chemotherapy. However, there was progressive elevation of liver enzymes, which could be attributed to neoplastic hepatic infiltration. Chlorambucil and prednisolone were administered until day 108, when the liver enzyme levels normalized. On day 156, the dog developed diffuse large B-cell lymphoma (DLBCL) of the peripheral lymph nodes. Sequence analysis of the clonally rearranged IgH gene revealed that all neoplastic cells in the spleen, gallbladder, and liver at initial presentation, as well as lymph nodes on day 156, possessed the same sequence identity of the amplified IgH fragments. This demonstrated that all neoplastic cells were derived from the same B-lymphocyte clone. The DLBCL was considered to have transformed from the splenic MZL, with gallbladder involvement. In cases of splenic MZL, it is important to consider gallbladder involvement and transformation to DLBCL. Moreover, gallbladder lymphoma should be included in the differential diagnosis of dogs with gallbladder abnormalities. Further studies are warranted to investigate the prognosis of splenic MZL.