Successful treatment with radiation therapy for desmoid-type fibromatosis with unilateral hydronephrosis: a case report

Background: Desmoid-type fibromatosis is a rare disease that can result in hydronephrosis. Hydronephrosis associated with desmoid-type fibromatosis often requires surgery or ureteral stent insertion. Although radiation therapy is recommended for inoperable cases of desmoid-type fibromatosis, there has been no report of treatment for hydronephrosis associated with desmoid-type fibromatosis by radiation therapy alone. We herein report a case of successful treatment for inoperable recurrence of desmoid-type fibromatosis with unilateral hydronephrosis by radiation therapy alone. Case presentation: A 43-year-old Japanese female underwent resection of desmoid-type fibromatosis in the right inguinal region and combined resection of the right external iliac vein 5 years before. Other treatment was not performed because of her pregnancy. Four years after surgery, desmoid-type fibromatosis recurred in the right pelvic wall. Cyclooxygenase-2 selective inhibitor treatment was given for 1 year, but her desmoid-type fibromatosis enlarged to more than 10 cm, and she had swelling of her right leg and hydronephrosis of her right kidney. The patient received 50.4 Gy in 28 fractions of prophylactic irradiation using 10 MV X-ray and 9 Gy in five fractions of a sequential boost for the recurrent desmoid-type fibromatosis. Although there was temporary tumor progression at 1 month after radiation therapy, slow regression of the tumor was seen. At 5 years after radiation therapy, there was no disease progression or severe complications. Conclusion: We experienced successful treatment for an inoperable case of desmoid-type fibromatosis with hydronephrosis. Moderate-dose radiation therapy alone is an effective and feasible approach for the management of hydronephrosis associated with desmoid-type fibromatosis.