Benign clear cell tumor (“sugar tumor”) of the lung

Abstract

The light microscopic and fine structural features of a benign clear cell tumor of the lung are reported. The tumor contained an abundance of glycogen which was present both free and membrane-bound. The resemblance of this glycogen distribution to that seen in type II glycogenosis (Pompe's disease) is noted. In some tumor cells, dense-core (neurosecretory) type granules and modification of the endoplasmic reticulum were noted similar to those reported in pulmonary carcinoid tumors. The fine structural features of this tumor may be helpful in its differential diagnosis. The pulmonary clear cell tumor appears to belong to that family of pulmonary neoplasms derived from the Kultschitzky cell.