Pulmonary large cell carcinoma with rhabdoid phenotype.

A 70-year-old woman presented with a coin lesion in her left lung. The tumor was well circumscribed and had a large area of central necrosis with a thin rim of viable tumor cells. It showed a solid growth pattern of polygonal cells with eosinophilic intracytoplasmic inclusion bodies. Immunohistochemically, the tumor cells were positive for vimentin, neural cell adhesion molecule, neuron-specific enolase, and vascular endothelial growth factor. Electron microscopy revealed intracytoplasmic inclusion bodies consisting of whorled intermediate filaments. Based on histological and immunohistochemical findings, the patient was diagnosed as having pulmonary large cell carcinoma with rhabdoid phenotype (LCCRP). The patient was in stage IA, and the histological findings may be the prototype of pure LCCRP. The tumor recurred after 6 years, and the second tumor had more apparent intracytoplasmic inclusion bodies. It is worthwhile detecting and recognizing the significance of these intracytoplasmic inclusions because of the poor prognosis of this tumor.