HPV-positive cervical squamous cell carcinoma metastasis to the breast, mimicking primary tumor.

INTRODUCTION: Metastatic disease to the breast is a rare condition, with contralateral breast metastasis being the most common primary site. CASE PRESENTATION: We present the case of a patient who underwent treatment for an HPV positive squamous cell carcinoma (SCC) of the cervix who, during follow-up, complained of a nodule in her left breast. Anatomopathological results indicating squamous carcinoma, which was not able to be differentiated from breast metaplastic carcinoma. Resection of the lesion was carried out, confirming carcinoma with squamous cell differentiation with negativity for GCDFP-15, mammaglobin, p63 and SOX10, but with positivity for p16 and for high risk HPV, confirming a single metastatic lesion of cervical carcinoma. DISCUSSION/CONCLUSION: In the presence of SCC in the breast, the differential diagnosis may consider the presence of primary lesion, metaplastic carcinoma with squamous cell differentiation or metastatic disease. The use of markers such as p63, SOX10 and p16, may help for a definitive diagnosis.