psammoma body
Pronunciation: sam-OH-ma body
Calcified, concentric lamellar structures commonly found in meningiomas and some other tumors.
Full Definition
Round, concentrically laminated calcified structures that appear as distinctive microscopic features in certain brain tumors, most characteristically in meningiomas. These structures consist of calcium phosphate and carbonate deposits arranged in concentric layers, resembling grains of sand (psammoma derives from the Greek word for sand). While not pathognomonic, psammoma bodies are highly suggestive of meningioma when found in appropriate clinical and histological context. They can also rarely occur in other tumors such as papillary thyroid carcinoma and serous ovarian tumors.
Usage
Usage note: Note the silent 'p'; distinguish from other types of calcifications in brain tissue.
In Context
- "Numerous psammoma bodies were identified throughout the meningioma." — microscopic description
- "The presence of psammoma bodies supported the diagnosis of meningothelial meningioma." — pathology consultation