Granular cell tumour of the breast: A rare mimic of breast carcinoma.

Introduction: Granular cell tumours are rare lesions that can mimic breast carcinoma due to their shared radiological and clinical characteristics. As they are almost always benign, it is important to include these lesions as a differential during triple assessment. Case Report: A 43-year-old female was referred to the breast clinic after an incidental finding of a lesion on her left breast detected on a computed tomography scan. Clinical assessment was unremarkable. Ultrasound revealed a poorly defined hypoechoic lesion with distal acoustic shadowing and perilesional hyperechogenicity. These findings, along with mammographic examination, were considered highly suspicious for malignancy; therefore, ultrasound-guided percutaneous core biopsy was undertaken. This confirmed a diagnosis of granular cell tumours. After multidisciplinary team discussion, the lesion was surgically excised, with annual clinical examination and surveillance mammography arranged for the next 5 years. Conclusion: Granular cell tumours of the breast are usually benign, although they may have imaging characteristics similar to those of breast malignancy. Biopsy should be performed to confirm the diagnosis as the prognosis and management strategies differ significantly from breast carcinoma.