Psammoma bodies in small cell carcinoma of the lung: a case report.

Psammoma bodies are ovoid, laminated concretions that, when detected in malignant effusions, suggest the existence of an underlying papillary carcinoma, usually of the thyroid gland, ovary or endometrium. Although psammoma bodies have been reported to arise from a wide variety of papillary tumors, origin in a carcinoma of the lung is uncommon, and origin in small cell carcinoma has not been previously reported. This paper documents an unusual case in which psammoma bodies were detected in a malignant pleural effusion in a patient with small cell carcinoma of the lung. Autopsy demonstrated their site of origin to be visceral pleura of lung and a metastatic nodule on the pleural surface of the diaphragm.