Psammoma body

File:Meningioma showing Psammoma body.jpg

Micrograph of psammoma body in the centre of the field in a meningioma of brain. H&E stain.

A psammoma body is a round collection of calcium, seen microscopically. The term is derived from the Greek word ψάμμος (psámmos), meaning "sand".

Etiology

Psammoma bodies are associated with the papillary (nipple-like) histomorphology and are thought to arise from (1) the infarction and calcification of papillae tips and (2) 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
• Micropapillary subtype of lung adenocarcinoma
• 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
• Mesothelioma, in membranes that line body cavities

Benign lesions

File:Psammomatous melanotic schwannoma - very high mag.jpg

Micrograph of a psammomatous melanotic schwannoma with a psammoma body, as may be seen in Carney complex. H&E stain.

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.

External links

Slides:

• Meningioma
• Thyroid cancer
• Endometriosis (peritoneum)
• Video of psammoma bodies in meningioma