Carcinomatous-like mastitis due to axillary lymphadenopathy in a case of nasopharyngeal carcinoma: A case report.

Nasopharyngeal carcinoma (NPC) is a rare form of malignancy, accounting for 2% of all cancers of the head and neck in Europe. Axillary lymph node metastases are very rare in these cases. This is a case report of a 40-year-old premenopausal woman diagnosed in May 2015 with T1N2M0 stage III NPC, treated with induction chemotherapy, followed by chemo-radiotherapy. Post-therapeutic computed tomography (CT) scan showed partial response (PR) on the primary tumor and complete response (CR) on the latero-cervical lymph nodes. In 2017, our patient developed left carcinomatous-like mastitis with axillary lymphadenopathy. This raised suspicions of a carcinomatous mastitis. The pathology report with immunohistochemistry (IHC) of the third biopsy highlighted axillary metastasis of a non-keratinizing squamous cell carcinoma (NSCC). There are very few references in the literature regarding axillary metastases from squamous cell carcinoma of the head and neck (HNSCC). As far as we know, this is the first case report of mastitis due to NPC. To conclude, treatment consisted of two surgical excisions of axillary lymphadenopathy associated with local radiotherapy and chemotherapy (neo-adjuvant, adjuvant). The second surgery, performed after radiotherapy, required plastic surgery. A psychiatric evaluation was necessary, revealing a reactive anxiety disorder. This case required multidisciplinary management, where oncology, plastic surgery, pathology and psychiatric specialists collaborated in deciding the therapeutic approach.