Esthesioneuroblastoma: a Danish clinicopathological study of 40 consecutive cases.

Aims. To review all cases of esthesioneuroblastoma in Denmark from 1978 to 2000 with respect to staging, grading, histopathological and immunohistochemical evaluation, and prognostication. Methods and results. Possible cases of esthesioneuroblastoma were retrieved from Danish oncology departments. Patients were included on the basis of review of their files or pathology reports, and/or on the basis of histopathological and immunohistochemical examination. Forty-nine possible cases were retrieved. Nine cases were excluded. Esthesioneuroblastoma is a malignant neuroendocrine tumour originating in the olfactory mucosa. It is a small blue cell neoplasm with a characteristic lobular architecture. It has a neuroendocrine immunophenotype and a sustentacular S-100 staining pattern. The tumours were staged according to Kadish and graded according to Hyams. Kaplan-Meier survival analysis was used to identify prognostic factors. Conclusion. The Kadish staging system was able to group the patients into prognostically relevant groups. Intracranial involvement and metastases at the time of diagnosis were found to be poor prognostic factors. Hyams grading system is difficult to work with and it was not possible to divide patients into prognostically relevant groups. Presence of necrosis, a diffuse growth pattern and a high proliferation index proved to be equally poor prognostic factors.