Recurrent secretory carcinoma in residual mammary tissue after mastectomy.

A case of secretory carcinoma recurrent in residual breast parenchyma 8 years after modified radical mastectomy is described. The patient, 27 years old at the time of initial diagnosis, was disease free until two chest wall nodules appeared. The recurrent and primary carcinomas were identical and exhibited the mixed solid, papillary, and microacinar growth patterns characteristic of secretory carcinoma. Intraductal and invasive carcinoma involved fibrous tissue and mammary lobules remaining at the site of previous mastectomy. Immunohistochemical staining for alpha-lactalbumin was strongly positive; the carcinoma did not express estrogen or progesterone receptor proteins. Flow cytometric DNA analysis showed a diploid tumor with a synthetic phase of 10%. No further evidence of recurrent carcinoma developed during the ensuing 11 months of follow-up, without adjuvant chemotherapy or radiation. It is important to recognize the morphologic features of this unique form of invasive carcinoma because of its exceptionally good prognosis. Long-term follow-up is mandatory because of the potential for late locoregional recurrence, even after mastectomy.