Atypical Carcinoid Tumor Metastatic to the Parotid Gland: A Case Report and Review of the Literature.

Metastatic carcinoid tumor to the salivary glands is an extremely rare occurrence. The authors present a case of a 65-year-old female with a remote history of pT1aN0 atypical carcinoid tumor of the lung status-post resection and class 3 heart failure that was found to have locally advanced disease recurrence on imaging performed for heart transplantation evaluation. Fine-needle aspiration cytology (FNA) performed on mediastinal lymph nodes revealed metastatic atypical carcinoid tumor. This prompted a CT scan of the head for non-small cell lung cancer staging, which showed a parotid nodule that was suspicious for neoplasm. FNA of this nodule demonstrated small groups of cohesive, relatively bland spindle to epithelioid cells with neuroendocrine features, including eccentric nuclei, salt and pepper chromatin pattern, and inconspicuous nucleoli, with no apparent mitoses or necrosis. These findings were consistent with the known metastatic atypical carcinoid tumor. This is the first report of a case of metastatic atypical carcinoid tumor to the salivary glands with described cytopathological findings. A review of the literature revealed four cases of metastatic carcinoid tumors to salivary glands. This report shows the evolution of diagnostic capabilities and highlights the importance of cytopathology as a tool in the diagnostic process.