PERIPHERAL LUNG CARCINOMAS ASSOCIATED WITH CENTRAL FIBROSIS AND MIXEDSMALL-CELL AND OTHER HISTOLOGIC COMPONENTS

Three cases of peripheral small cell lung carcinoma (SCLC) with centra l fibrosis are presented. Central fibrosis is usually present in adeno carcinomas, Cases 1 and 2 are combined SCLCs with components of papill ary adenocarcinoma, and case 3 is a mixed SCLC with a large cell compo nent. Small cell components showed intermediate cell type in all cases . In cases 1 and 2, there was a gradual transition between small cell carcinoma and papillary adenocarcinoma. Small cell components showed G rimelius argyrophilia, but other neuroendocrine markers such as neuron specific enorase, chromogranin A, Leu-7 and synaptophysin were negativ e. The chest X-ray examination of case 1 demonstrated rapid enlargemen t of a tumor shadow, which was present two years before, for a recent year, Central fibrosis, coexistence of small cell carcinoma and papill ary adenocarcinoma, and a change of growth rate in the chest X-ray may suggest that some SCLC derive from papillary adenocarcinomas.