Papillary carcinoma of breast with apocrine change clinically masquerading as fibroadenoma

: Introduction: Invasive papillary carcinomas comprise 1-2% of all invasive cancers of breast and are associated with a good prognosis. We report a case of invasive papillary carcinoma of breast with apocrine change and apocrine adenosis , clinically masquerading as a fibroadenoma of breast. Case history: A 34 year old woman complained of swelling in the right breast of 4 years duration. A clinical diagnosis of fibroadenoma/ carcinoma? was given . FNA gave a diagnosis of a cystic breast lesion. Patient underwent lumpectomy and specimen was sent to histopathology. On gross examination, four separate swellings were seen, largest measuring 5x4x3 cms and the smallest measuring 1x1x1cm. H& E stained sections of the larger swelling showed tumor cells arranged in papillary structures with fibrovascular core, invading into the surrounding stroma. Areas of apocrine adenosis were also noted. Immunohistochemistry for SMA was done and showed absence of myoepithelial cells in areas of invasive papillary cancer. Conclusion: Papillary carcinoma is a rare malignancy of the breast which may be missed clinically and on aspiration cytology. In doubtful cases, immunohistochemistry may be necessary to arrive at a definitive diagnosis.