Penile hemangiosarcoma as a cause of stranguria in a dog: clinical presentation, imaging findings, treatment and outcome.

Background: Penile tumors are rare in dogs and only single case reports or small case series have been reported.

Case description: An 11-year-old, cross-breed dog was presented for a two-week history of stranguria. At physical examination, a subcutaneous swelling of the penis was detected. Abdominal radiographs, ultrasonography, and CT showed a subcutaneous penile mass involving the penile urethra and bulbus glandis associated with marked lysis of the os penis. Histological features along with the neoplastic cell positivity to CD31 and FVIII immunohistochemical markers warranted a final diagnosis of penile hemangiosarcoma.

Findings/treatment and outcome: The dog was treated with amputation of the penis, scrotal urethrostomy, and five adjuvant doses of doxorubicin along with thalidomide. Cutaneous and omental metastases were found 235 days after surgery. The dog was euthanized at 296 days due to bone and pulmonary metastasis.

Conclusion: Penile hemangiosarcoma seems to share the same aggressive behavior with other hemangiosarcomas seen in other anatomical locations. Therefore, surgery and chemotherapy may improve survival time in dogs with penile hemangiosarcoma as well.