We report a case of cystic hypersecretory carcinoma of the breast containing hyperplasia and dysplasia in a Japanese female patient in her 70’s.
It was not easy to obtain the final diagnosis by FNAC, because of the presence of various grades of dysplasia and hyperplasia. Histology revealed obviously hyperplastic benign epithelium and various grades of dysplasia in the cyst walls. A micropapillary growth pattern was detected in parts, with increased Ki-67 labelling, suggestive of malignancy.
Cytologists and pathologists should bear in mind this very characteristic breast lesion in cases with multicystic lesions of the breast detected by ultrasound and histopathology.