Psammoma Body

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".

Cause

Psammoma bodies are associated with the papillary (nipple-like) histomorphology and are thought to arise from,

1. Infarction and calcification of papillae tips.
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
• 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

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.