The 19 years old woman presented with approximately four weeks history of painless 5 × 5 cm breast lump/lumpiness. There was no history of trauma, nipple discharge or relation with menstrual cycle. There was no known family history of breast cancer. Palpation revealed a non-tender, mobile, hard left upper quadrant left breast lump. Mammogram was not performed given the very young age of the patient. Ultrasound revealed a prominent diffuse hypoechoic lesion. It appeared to be most likely benign lesion but as there was an element of uncertainty as to the nature of the lump on ultrasound, an ultrasound guided core biopsy (14G needle) was performed.
The core biopsy of the concerned area revealed parenchymal-rich breast tissue with columnar cell change and epithelial hyperplasia. In addition, there was fibroblastic stroma with focal elastosis containing an infiltrative adenosquamous proliferation. Diagnostic excision was recommended by the breast multi-disciplinary team (MDT) as the lesion appeared benign but with uncertain malignant potential.
As shown in Figures , and , subsequent diagnostic excision biopsy showed an ill-defined area of benign adenosis set in fibroblastic stroma with focal elastosis suggestive of a radial scar or complex sclerosing lesion. Within this lesion there was an infiltrative proliferation of angulated glands showing adenosquamous features. A proportion of these glands lacked definite myoepithelial layers and the tumour expressed immunoreactivity to p63 gene antibody assay. Both the sclerosing lesion and the adenosquamous proliferation extended up to the excised margin. Hence, a wide local excision was deemed necessary.
Figure 1 Sclerosing lesion with central fibrosis and radiating parenchyma. A low magnification (×20) view of the lesion. It has the characteristics of a sclerosing lesion with central fibrosis, entrapped parenchyma and radiating islands of tissue rich (more ...)
View of one of the radiating arms of the lesion. A view (×20) of one of the radiating arms of the lesion showing parenchymal tissue separated by a diagonal band of infiltrative cellular stromal tissue containing small ductal like structures.
Figure 3 Infiltrative but bland stromal tissue with ductal and epithelial structure. A high magnification view (×40) of the infiltrative but bland cellular stromal tissue, along with the accompanying ductal and small epithelial structures. This combination (more ...)
The wide local excision specimen showed residual spindle cell lesion with squamoid islands seen in the infero-lateral shave specimen taken during wide local excision.
External opinion was sought from international experts (as acknowledged later) in this uncommon histological subtype of breast cancer. The consensus view was that it was low grade adenosquamous carcinoma.
Due to reported low potential for metastasis but high potential for local recurrence, she underwent Skin-sparing mastectomy with immediate Latissimus Dorsi flap reconstruction with an implant.
Following mastectomy, no further adjuvant therapy was deemed necessary due to the completeness of resection in the specimen histopathology and also due to the reported low metastatic potential and no known increased risk of contra-lateral disease. It was decided to simply follow-up patient clinically annually for five years due to known high risk of local recurrence and then to mammogram screening programme.