Malignant small-cell tumor of the thoracopulmonary region: 'Askin tumor'.

Malignant small-cell tumor of the thoracopulmonary region (MSCT) is an uncommon neoplasm in children. We describe five cases diagnosed since 1981 that fulfill the criteria put forth by Askin et al. Surgery was performed for diagnosis or therapy in all patients. Two patients underwent open lung biopsy, only because of tumor extent. The other three had chest wall resections. All patients received radiotherapy and chemotherapy. Three patients presenting initially with extensive disease died at intervals of 2.5 to 7 months after diagnosis. Two patients are alive and disease-free at 16 and 24 months postdiagnosis. All five cases were reviewed for standard histology and differential immunohistochemistry. Electronmicroscopy and tissue cultures were done in 3 of the 5 patients. All five patients were neuron-specific enolase-positive. MSCT is an exclusion diagnosis not always readily made. Clinical course and pathologic expertise may point to the correct diagnosis.