Giant juvenile fibroadenoma is a rare variant of more common benign lesion, fibro adenoma observed in younger population. They present with rapidly enlarging single or multiple breast masses in one or both the breast. A 10-year-old pre-pubertal girl presented with large lump in left breast followed by right breast lump. FNAC was suggestive of fibroadenoma, and histopathology confirmed the diagnosis. To understand the genetic basis of common entity like fibroadenoma with a rare presentation in very young age, the tissue block was subjected to gene sequencing and identified MED 12 gene mutation. It leads us to the possibility of new treatment modalities of targeting the causative gene and thus sparing the patient from invasive procedures.