Axillary Neuroendocrine Carcinoma: A Case Report and Review of the Literature

Neuroendocrine tumors (NETs) represent neoplastic growths that arise from cells of neuroendocrine differentiation. They constitute a clinical spectrum from low-grade NETs with an indolent course to the aggressive undifferentiated high-grade neuroendocrine carcinoma. We report a rare case of axillary neuroendocrine carcinoma of unknown primary site. The patient underwent axillary nodal excision followed by radiation therapy with good tolerability. However, distant cerebellar metastatic recurrence was evident 9 months later. We additionally review the literature on cases of axillary NETs. Their heterogenous behavior depict the need for strict clinical surveillance to allow for early identification of occult secondary metastasis and improve prognostic outcomes.