Epiploic appendagitis is an uncommon cause of acute abdominal pain, often mimicking surgical emergencies. This case highlights the diagnostic process for epiploic appendagitis in a breast cancer patient receiving adjuvant abemaciclib, a CDK4/6 inhibitor, and discusses potential associations with targeted therapies.

We present a case of a 48-year-old female on adjuvant abemaciclib for Stage IIIA breast cancer who developed acute left iliac fossa (LIF) pain. Clinical assessment, laboratory investigations, transvaginal ultrasound, and subsequent computed tomography (CT) imaging of the abdomen and pelvis were performed to establish the diagnosis

CT imaging revealed a characteristic oval fat-density lesion with surrounding inflammation adjacent to the sigmoid colon, consistent with epiploic appendagitis. Other differential diagnoses, including ovarian pathology and diverticulitis, were excluded. The patient was managed conservatively with analgesia and discontinuation of abemaciclib, leading to symptom resolution. This case underscores the importance of considering epiploic appendagitis in the differential diagnosis of acute abdominal pain, particularly in patients on targeted therapies like abemaciclib, which are known to have gastrointestinal side effects. Timely and accurate diagnosis via imaging avoided unnecessary surgical intervention.

This case emphasises the crucial role of clinical suspicion and appropriate imaging in the diagnosis of rare conditions like epiploic appendagitis in cancer patients on targeted therapies. Further research is warranted to explore potential links between CDK4/6 inhibitors and the development of epiploic appendagitis.