A psammoma body is a round collection of calcium, seen microscopically. The term is derived from the Greek word ψάμμος (psámmos), meaning "sand". Cause Psammoma bodies are associated with the papillary (nipple-like) histomorphology and are thought to arise from, Infarction and calcification of papillae tips. Calcification of intralymphatic tumor thrombi. Association with lesions Psammoma bodies are commonly seen in certain tumors such as: Papillary thyroid carcinoma Papillary renal cell carcinoma Ovarian papillary serous cystadenoma and cystadenocarcinoma Endometrial adenocarcinomas (Papillary serous carcinoma ~3%-4%) Meningiomas, in the central nervous system Peritoneal and Pleural Mesothelioma Somatostatinoma (pancreas) Prolactinoma of the pituitary Glucagonoma Micropapillary subtype of Lung Adenocarcinoma Benign lesions Psammoma bodies may be seen in: Endosalpingiosis Psammomatous melanotic schwannoma Melanocytic nevus Appearance Psammoma bodies usually have a laminar appearance, are circular, acellular and basophilic. References External links Slides: Meningioma Thyroid cancer Endometriosis (peritoneum) Video of psammoma bodies in meningioma Histopathology