Transitional cell carcinoma (TCC) of the urinary bladder carries the highest documented seeding risk among veterinary tumor types, and owners should be counseled that this risk exists for both needle-based procedures and surgical instrumentation.Journal of the…

For TCC specifically, needle-tract seeding is considered more likely than with other tumors, though the exact incidence in dogs is unknown.Journal of the… For context, the incidence in men with prostatic neoplasia following needle procedures is less than 1%, and canine TCC seeding risk is not quantified but has been described in multiple reports.Journal of the… Coaxial biopsy techniques carry lower seeding rates than techniques that create a new needle path with each pass, and seeding risk is highest when the needle is withdrawn through the skin after sampling a mass.Journal of the…

Prostatic carcinoma in dogs is a confirmed seeding risk, with needle-tract seeding documented following both fine-needle aspiration of the prostate and cystocentesis.Veterinary Reco… In the reported canine case, a para-preputial cutaneous mass and regional lymphadenopathy consistent with seeding appeared 8 months after the initial procedures.Veterinary Reco…

Pancreatic carcinoma in cats carries seeding risk even with fine-needle aspiration alone. In the reported feline case, two separate fine-needle aspirations were performed 2 weeks apart, and a subcutaneous nodule consistent with needle-tract seeding appeared on the left ventrolateral abdomen within 2 weeks of subsequent partial pancreatectomy; the cat survived a further 136 days with palliative treatment.Journal of Feli… The authors recommend minimizing the number of needle passes where possible.Journal of Feli…

Hepatocellular tumors in dogs represent an additional seeding risk, including the possibility of malignant transformation at the seeding site. In the reported canine case, a hepatocellular adenoma was sampled via core-needle biopsy, and a nodule in the abdominal wall musculature appearing 18 months later was diagnosed as well-differentiated hepatocellular carcinoma, with immunostaining suggesting malignant transformation relative to the original liver mass.Veterinary Clin…

Surgical seeding is documented beyond needle procedures. Feline intracranial meningioma has been reported to seed subcutaneously at the surgical site, with two subcutaneous masses histologically identical to the primary tumor identified at the original craniotomy site 12 months after first surgery, fully separated from the recurrent meningeal tumor by intact frontal bone.Tieraerztliche… Seeding of TCC can also occur at laparoscopic trocar sites through tumor extraction, instrument contamination, and peritoneal decompression.Journal of the…

Owner counseling should address three key points: seeding risk is tumor-type dependent and highest for TCC, prostatic carcinoma, and pancreatic carcinoma; the number of needle passes should be minimized and coaxial technique used where feasible; and surgical seeding, while rare even for benign tumors such as grade I meningioma, remains a documented possibility.Journal of Feli…+4

Would you like guidance on how to modify biopsy technique — such as coaxial approach or ultrasound guidance — to reduce seeding risk for any of these specific tumor types?