Primary squamous cell carcinoma of the breast during lactation: a case report

A case of primary squamous cell carcinoma of the breast during lactation is reported. The patient was a 32-year-old woman, in post-partum lactating 18 months after delivery, who was referred to our hospital following detectio n of a lump in her left breast during physical examination in mass screenin g for breast cancer. The tumor, palpated in the upper outer quadrant of the left breast, was firm, well-defined and 2.8 x 2.6 cm in size. Ultrasonogra ms identified an irregular-shaped hypoechoic lesion and mammograms revealed a well-defined, circumscribed tumor. Based on these findings, breast cance r was suspected and an excisional biopsy was performed. The resected specim en was a firm, solid and circumscribed tumor with central hemorrhage, Micro scopic findings demonstrated that the tumor consisted of an invasive ductal carcinoma with marked squamous metaplasia, such as keratinization and squa mo-columnar junction, Breast-conserving surgery was performed and no lymph node involvement was noted. Both estrogen and progesterone receptors of the tumor were negative. Generally, the size of both squamous cell carcinoma a nd carcinoma during the lactation period tends to be larger than ordinary c arcinomas. In this case, the cancerous lesion was detected at a relatively early stage. Although the cancerous lesion was detected at a relatively ear ly stage and no lymph node involvement was noted, lung metastases occurred within 12 months of the surgery. Malignant potential is generally considere d to be high in cases of squamous cell carcinoma of the breast with lactati on and thus intensive treatment potentially resulting in severe side effect s was considered to be necessary for this patient.