RESUMEN
BACKGROUND: The majority of malignancies after transplantation appear to be virally mediated and of recipient origin. Donor-derived neoplasms occur early, whereas recipient-origin tumors typically occur many years after transplantation. Sarcomas are a relatively rare form of cancer. The etiology of sarcomas remains largely unknown, although some are linked to viruses, familial cancer syndromes, or therapeutic radiation exposure. Primary sarcomas are extremely rare, accounting for <0.1% of all native pancreatic malignancies. The involvement of the allograft itself in the tumor is rare. CASE REPORT: A 53-year-old white woman (body mass index, 20.1 kg/m2) with a history of type 1 diabetes, chronic kidney disease, coronary artery disease, dyslipidemia, and pancreas-alone transplantation in 2007 was admitted with small bowel obstruction secondary to a mass in the head of the pancreas allograft, for which a laparotomy with allograft pancreatectomy was required. Histopathologic exam revealed a stage III high-grade unclassified spindle cell sarcoma positive for polyomavirus. After surgery, the patient was managed with close monitoring for disease recurrence. Her most recent scan was negative for recurrence at postoperative day 489. CONCLUSIONS: We report a previously unreported phenomenon of a soft tissue sarcoma arising in a pancreas allograft, likely of recipient origin and polyomavirus related. Standard treatment for sarcoma is wide excision of the tumor and close monitoring for recurrence. Systemic chemotherapy or radiotherapy is usually limited to advanced cases. Sarcomas may occur in a pancreas allograft. Allograft pancreatectomy and monitoring for recurrence is vital for a good outcome.