a 15-year - old girl was presented with lump in the right breast since 8 month . lump was rapidly increasing in size with no other significant history available . on examination 1312 cm mobile lump with visible vessels on the overlying skin in the upper and inner quadrant was present ( figure 1 ) . lump was firm to hard , and was free from overlying skin and underlying structure . there was no history of risk factors for malignancy of breast .general examination did not revealed any findings consistent with metastatic disease . excision biopsy showed well defined smooth mass with 131112 cm size and weight of 800 gm ( figure 2 ) . she had a normal breast development over a period of 8 month follow up . although simple fibroadenoma is a disorder of breast development , giant fibroadenoma is a disease . it is the most common tumor of the breast in a female younger than 30 years . jgf is characterized by rapid growth , large size , stretching of the overlying skin , and dilatation of superficial veins . it is usually single and > 5 cm in size /or > 500 gms in weight . the usual age of presentation of phyllodes tumor is more than 35 years ( rarely reported in puberty ) and increased stromal cellularity , pleomorphisim , and the presence of mitotic figures points towards phyllodes tumor rather than fibroadenoma . juvenile gigantomastia is characterized by its positive estrogen receptor status and its hypersensitivity to estrogen . other differential diagnosis includes : giant lipoma , juvenile breast hypertrophy , and great hamartoma . multiple giant fibroadenomas ( mgf ) are rare and reported to occurs usually in adolescent black females . the high sensitivity of mri for cancer detection raised the possibility that it could replace biopsy in future . differentiation of giant juvenile fibroadenomas from phyllodes tumor on basis of trucut biopsy is difficult . wide excision or mastectomy should be performed , if required , on the basis of final histopathological diagnosis . high index of suspicion is required for the diagnosis . surgical excision remains the cornerstone of the treatment . the approach should be determined by the surgeon s preference , skills , and experience . depending on the size of the tumor , age of the patient , and stage of sexual maturity , reshaping of the breast after the removal of the tumor may be necessary . the challenge to the physician is to differentiate it from phyllodes which may require aggressive treatment .
fibroadenomas are benign solid tumor associated with aberration of normal lobular development . 
 juvenile giant fibroadenoma is usually single and > 5 cm in size /or > 500 gms in weight . 
 important differential diagnoses are : phyllodes tumor and juvenile gigantomastia . 
 simple excision is the treatment of choice .