Primary small cell neuroendocrine carcinoma of the vagina: a clinicopathologic study.

CONTEXT: Primary small cell neuroendocrine carcinoma of the vagina is extremely rare, and its clinical behavior is aggressive. To our knowledge, 22 patients with this tumor have been reported in the English literature to date.
OBJECTIVE: To investigate 3 patients with this tumor clinically and pathologically.
DESIGN: The pathology database at the University of Texas Medical Branch at Galveston was searched, and 3 cases of primary small cell neuroendocrine carcinoma of the vagina were found. The histologic, immunohistochemical, and ultrastructural profiles of the tumors were investigated. The medical charts of the patients were reviewed, and the patients were followed up. PATIENTS: Women with the diagnosis of primary small cell neuroendocrine carcinoma of vagina.
RESULTS: All 3 patients presented with advanced disease, and 2 patients died within 4 months of the initial diagnosis. One 38-year-old patient was newly diagnosed, and her clinical outcome had not yet been determined. The histologic features of all 3 tumors were similar to those of their pulmonary counterpart. All cases were positive for cytokeratin, chromogranin A, and synaptophysin. The expression pattern of thyroid transcription factor 1 was examined in all 3 patients, of whom 2 were negative and 1 was positive with negative clinical and radiologic thyroid or pulmonary findings. Ultrastructural evaluation showed scattered intracytoplasmic electron-dense neurosecretory granules.
CONCLUSION: Primary small cell neuroendocrine carcinoma of the vagina has histologic, immunohistochemical, and ultrastructural features similar to those of its pulmonary counterpart. Because thyroid transcription factor 1 can be positive, it should not be used to differentiate primary from metastatic disease. The current therapies have usually resulted in poor outcomes, and new therapeutic modalities should be explored.