Objective: Metaplastic Breast Carcinoma (MBC) is a rare subtype of breast cancer which often involves women in the fifth and sixth decades. Herein, we report a rare case of MBC with squamous cell carcinoma (SCC) morphology, presented in a young breast-feeding woman with recurrence and metastasis.

Patients and Methods: A 29-year-old female was admitted with left breast mass unresponsive to chemo-radiation for mastectomy. The mass was noticed by the patient starting from 10 months before, during breast feeding. First surgery at the same time confirmed MBC with squamous cell carcinoma morphology. Second surgery one month later showed involvement of two out of six axillary lymph nodes.

Results: Immunohistochemistry was done with the following results: estrogen, progesterone, androgen receptors, human epidermal growth factor receptor 2 (HER2) and P53 negative. Ki-67 was present in 30% of tumor cells. Third surgery was consisted of mastectomy and lymph node dissection which confirmed remnants of malignancy but free lymph nodes. Four months later on follow-up, imaging findings suggested metastasis to lungs and kidneys.

Conclusions: We reported a rare case of breast carcinoma with pure SCC morphology which presented at a young age (less than 30 years in spite of more than 50 years in the usual presentation) and the relatively rare occurrence of lymph node involvement in this subtype