[Extrabronchial small-cell carcinoma: apropos 6 cases]

Extrabronchial small cell carcinoma (ESCC) is an infrequent tumor with controversial histogenesis, clinical evolution and therapeutic strategy. The aim of this study was to know the immunohistochemical features and the clinical evolution of patients diagnosed of ESCC during a 10 year period. All the diagnoses of small cell carcinoma (bronchial and extrabronchial) carried out by the Unit of Pathology between 1980-1989 were reviewed. In all the ESCC an immunohistochemical study was performed with three neuroendocrine markers, chromogranin, neurospecific enolase and synaptophysin. The clinical evolution of the patients is described. The 6 patients with ESCC represented 4.7% of all the small cell carcinomas. The primary localization was: parotid, urinary bladder, the skin, maxillary sinus and esophagus (2 patients). In five cases positivity was observed for one or more of the neuroendocrine markers. In two cases the ESCC was associated with differentiated cell populations (squamous carcinoma). The diagnosis of ESCC logically obliges the bronchial origin and the presence of ectopic hormonal secretion syndromes to be discarded. The administration of chemotherapy regimes used in small cell lung carcinoma is advised.