Identification of serum microRNAs with differential expression between dogs with splenic masses and healthy dogs with histologically normal spleens.

OBJECTIVE: To identify differential microRNA (miRNA) expression in dogs with splenic hemangiosarcoma, splenic hematoma, and histologically normal spleens. ANIMALS: Dogs with splenic hemangiosarcoma (n = 10), splenic hematoma (n = 5), and histologically normal spleens (n = 5). PROCEDURES: Splenic tissue and serum samples were collected from dogs with splenic masses (ie, hemangiosarcoma or hematoma samples) and healthy control dogs (ie, control samples), and total RNA was extracted. Reverse transcription quantitative real-time PCR was performed with 28 miRNAs associated with hemangiosarcoma, angiosarcoma, or associated genes. Differential expression analysis was performed. RESULTS: Control tissue and serum samples had similar miRNA expression patterns, and hemangiosarcoma tissue and serum samples did not. Hemangiosarcoma serum samples had higher expression than hemangiosarcoma tissue for 13 miRNAs and lower expression for 1 miRNA. Control tissue and hemangiosarcoma tissue had varying expressions for 12 miRNAs, with 10 more highly expressed in control samples and 2 more highly expressed in hemangiosarcoma samples. Five miRNAs (miR-214-3p, miR-452, miR-494-3p, miR-497-5p, miR-543) had significantly different expression in serum between dogs with splenic masses (ie, hemangiosarcoma or hematoma) and serum of dogs with histologically normal spleens, with higher expression in the serum of dogs with splenic masses for all 5 miRNAs. CONCLUSIONS AND CLINICAL RELEVANCE: 5 circulating miRNAs were identified that distinguished dogs with splenic hemangiosarcoma or hematoma from those with histologically normal spleens. These 5 miRNAs had higher expression in dogs with splenic masses, indicating upregulation of these circulating miRNAs occurs in these splenic disease states. These miRNAs may be useful as a noninvasive screening tool that uses serum to identify dogs with splenic masses.

A Simulated Tumor for Teaching Principles of Surgical Oncology for Biopsy and Excision of Skin and Subcutaneous Masses to Veterinary Students.

Tumors of the skin and subcutaneous tissues are commonly encountered in primary care practice. The most common of these tumors are mast cell tumors and soft tissue sarcomas, for which the primary treatment is most often surgical excision. Understanding surgical margins, particularly the deep fascial plane, can be difficult for veterinary students. Current techniques to teach these concepts typically rely on cadaver-based laboratories, which require simulated tumors to improve the realism of the laboratory. Tumors can be difficult to replicate in cadaver laboratories; thus a new technique for a simulated tumor was developed. A gelatin-based simulated tumor was injected into the subcutaneous space in two different sites in canine cadavers. Students then practiced incisional biopsy and wide excision of a subcutaneous mass. Students were able to appropriately perform both techniques using the simulated tumors. When the deep margin was not clean on the wide excision, students were able to understand the error by identifying the simulated tumor, reinforcing the concept of obtaining an appropriate deep fascial plane. In summary, this gelatin-based simulated tumor technique was cost-effective, easy to perform, and effective for the teaching laboratory.