2006 Volume 45 Issue 2 Pages 106-110
Backgrounds: Pagetoid carcinoma accounts for 0.5% of all breast carcinomas and has a poor prognosis. Clinical and cytological features of Pagetoid carcinoma are similar to those of Pagefs disease, and differentiation of both from squamous cell carcinoma or melanoma may not always be possible.
Case: An 84-year old woman complained of eczematoid conditions of, and bloody discharge from the right nipple. In the nipple discharge specimens, there were many neutrophils, keratinizing squamous cells with varying degrees of atypism and some atypical epithelial cells. Cytological diagnosis was a squamous cell carcinoma with a differential diagnosis of adenocarcinoma. Pathological diagnosis of the biopsy specimen from the nipple skin was Paget's disease. After radical mastectomy of the right breast, pathological examination revealed a Pagetoid carcinoma, in which a solid-tubular type of invasive ductal carcinoma of 1.3 cm in size showed an extension into the nipple skin via the mammary ducts. Pagetoid carcinoma cells and ductal carcinoma cells were demonstrated to be immunoreactive for and-Her 2 antibody.
Conclusion: Even when atypical squamous cells are predominant in large amounts in nipple discharge specimens, glandular epithelilal cells may provide better diagnostic clues if there is an eczematoid area on the nipple. Immunostaining for anti-Her 2 antibody may be useful for the cytological diagnosis.
