Pelvic desmoid fibromatosis: a diagnostic and therapeutic challenge

Pelvic desmoid fibromatosis is a rare locally aggressive benign neoplasm, typically presenting in the reproductive age group with lower abdominal pain. Extra-abdominal occurrence being predominant, the pelvic origin of the tumour makes the clinical management a multidisciplinary challenge. Previous surgeries, current or previous pregnancies, and familial adenomatous polyposis have been documented as associated risk factors. Our patient was a young woman with three previous caesarean sections, admitted with a large infiltrative lesion extending into the left pelvic sidewall up to the pelvic bone, causing ipsilateral severe hydroureteronephrosis. Malignancy was suspected due to the infiltrating nature of the lesion on imaging. Due to its proximity to the pelvic veins, preoperative embolisation of the feeding vessel was done. An exploratory laparotomy was performed by a multidisciplinary team. For this deep-seated disease, mass excision was performed along with total hysterectomy, left salpingo-oophorectomy and left ureteroneocystostomy. A part of the lesion infiltrating the presacral fascia was not removed during the primary surgery. Within 24 hours of surgery, she developed critical limb ischaemia in the left limb due to thrombosis in the ipsilateral external iliac artery. An emergency thrombo-embolectomy was performed by the vascular surgeons and thromboprophylaxis continued. Final histopathology confirmed desmoid fibromatosis. For the residual disease, the patient has been under close follow-up and is receiving targeted therapy with oral sorafenib to prevent local progression. Her follow-up imaging showed a decrease in the size of the residual disease and she is asymptomatic currently.