Primary Neuroendocrine Carcinoma of the Breast with Clinical Features of Inflammatory Breast Carcinoma: A Case Report and Literature Review

Primary neuroendocrine carcinoma of the breast (NECB) is a very rare type of invasive breast carcinoma. Most NECBs appear on breast imaging as solid masses of varied shapes and margins, and have worse clinical outcomes than does invasive ductal carcinoma, not otherwise specified. However, there have been no reports to date regarding NECB with features of inflammatory breast carcinoma. Here, we describe the clinical, radiologic, and pathologic findings of the first reported case of primary NECB presenting as inflammatory breast carcinoma. The patient complained of diffuse right breast enlargement and erythema. Mammography identified severe breast edema and axillary lymphadenopathy. Ultrasound detected an irregular, angular, hypoechoic mass with dermal lymphatic dilatation. On magnetic resonance imaging, the mass had rim enhancement and the entire right breast showed heterogeneous enhancement with malignant kinetic features. Pathology identified the mass as a primary NECB with positive for synaptophysin, CD56, estrogen and progesterone receptors.