A case report of extra-abdominal desmoid tumor after kidney transplantation

Desmoid tumors are rare, locally invasive, non-metastasizing intermediate grade neoplasms. According to the organ procurement and transplantation network report, approximately one million solid organ transplants have been performed globally, from which only three desmoid tumors have been reported.

We present the case of a 61-year-old male who developed an asymptomatic abdominal mass 3 years after kidney transplantation. Computed tomography revealed a 50-mm mass attached to the Hem-o-lok clip beneath the right rectus abdominis muscle. A needle biopsy revealed β-catenin positivity, which raised suspicion for a desmoid tumor. Due to progressive tumor enlargement, surgical excision was performed. The patient was discharged on postoperative day 5 without any surgical complications.

This is the first documented case of an extra-abdominal desmoid tumor after kidney transplantation. Although no recurrence has been observed over a 5-year follow-up period, careful long-term monitoring is required because of the high recurrence rate of desmoid tumors.