What Are Psammoma Bodies?
Psammoma bodies are microscopic, round calcifications (collections of calcium salts). Since they resemble sand grains, their name is derived from the Greek word, sand. They also resemble an onion due to their concentric laminated appearance. Psammoma bodies are typically found in damaged tissues and are linked to both malignant cancers and some benign, non-cancerous conditions. Their primary function is to halt cancer growth and act as a barrier to the spread of malignant cancer cells. Although psammoma bodies are usually seen under a microscope, some can be detected using computerized tomography (CT) imaging.
What Is the Origin of Psammoma Bodies?
To determine the origin of psammoma bodies, the fine structure of human arachnoid villi was studied. Collagen fibrils and tiny granular particles gathered to form microcores of variable calibre that could reach a diameter of 10 m within the villous surface layer. In comparison to the meningocytic whorls, these villous microcores showed an earlier stage of psammoma body formation more frequently. The matrix granules in the villous microcores were largely membrane-free, while the matrix vesicles and minerals were mostly membrane-bound. The matrix granules had an electronlucent halo and were amorphous oval structures with a diameter of 0.05-0.70 m.. The matrix granules that aggregated with calcifying matrix vesicles and matrix minerals frequently precipitated hydroxyapatite crystals within and around them. There were lots of calcifying matrix granules inside and around the psammoma bodies as they grew. The matrix granules may act as the primary calcification nidi of psammoma bodies in human arachnoid villi. The secretion of fine granular material with its extracellular assemblage or the extrusion of preformed arachnoid cell structures are two potential mechanisms for matrix granule biogenesis.
How Are Psammoma Bodies Formed?
The exact mechanisms causing the development of psammoma bodies are unknown, but it is thought that they are brought on by the thickening of the basal lamina, the bottom layer of cells that frequently happens in some initial stages of cancer. Thrombosis (blood clotting), calcification, and tumor necrosis follow this peculiar process. Psammoma bodies may show an active process that causes tumor cells to degenerate and die, rather than the result of the calcification of dead tissue. Psammoma bodies in papillary thyroid carcinoma may be caused by thyroid tumor thrombi, which refers to a portion of the tumor that has migrated into the lymphatic system.
What Is the Histopathology of Psammoma Bodies?
PBs were found to have a round, largely intact cytomorphology, easily distinguishable concentric laminations, and a light reddish coloration upon Papanicolaou staining. Almost always, they were seen in connection with the cellular element. Isolated PBs in the slide background were only occasionally observed. The PBs were well formed and easily discernible structures in benign lesions such as endosalpingiosis or endometriosis, and they were well contained within the glandular lumina. The lining epithelial cells were seen to be strongly polarised in the vicinity of the fragments' edges. PBs have been observed to be related to tiny papillary-like fragments of mesothelium in cases of benign mesothelial hyperplasia and ovarian cystadenofibroma.The number of PBs in benign lesions was found to vary from rare (one to two) to few (three to five) in any given case. The number of PBs was typically higher (greater than five) in malignant effusion cases, such as ovarian carcinoma. The PBs could be seen more clearly in paraffin-embedded cell block sections. The PBs, on the other hand, were typically found to be fragmented structures that remained connected to the problematic cells.
Where Do Psammoma Bodies Reside?
Psammoma bodies can be found in various organs, including the endometrium, thyroid, ovaries, and the lining of the central nervous system. They can also be a symptom of long-term inflammation. They are present in both malignant and benign tumors. Particularly in benign ovarian tumors, cervical polyps, or growths on the cervical canal bridging the uterus and vagina are a few non-cancerous conditions in which psammoma bodies can be found. They are also seen in endometriosis (a condition in which the tissue lining the uterus spreads outside of the uterus).
Additionally, meningiomas, or tumors that develop on the meninges (the membrane that covers the brain and spinal cord inside the skull), can contain psammoma bodies. Meningiomas can be benign and non-cancerous in up to 90% of cases. The hormone-related tumors, prolactinoma and glucagonoma are non-cancerous and frequently exhibit psammoma bodies. Psammoma bodies can be detected after a biopsy of the tissue is taken and stained with haematoxylin and eosin (a primary tissue stain used in histology) in both benign and malignant conditions.
Numerous cancers contain psammoma bodies. They frequently serve as a diagnostic indicator for papillary thyroid carcinoma (the most prevalent type of thyroid cancer). When psammoma bodies are found in papillary thyroid carcinoma patients, the patient is typically more susceptible to lymph node metastasis (spread of cancerous growth) and high-stage cancer than patients without psammoma bodies. The technique of fine-needle aspiration (FNA), which involves taking a sample of cells from the thyroid gland at the front of the neck with a small hollow needle, is frequently used to find papillary thyroid carcinoma and other thyroid cancers.
The most common type of malignant ovarian cancer, papillary serous cystadenocarcinoma, also frequently exhibits psammoma bodies. Psammoma bodies can also be seen in other, less frequent cancers, such as some lung cancers, melanotic schwannoma, which is a rare tumor that develops in the nerve sheath lining the nerves that extend from the spinal cord into the body, and papillary serous carcinoma of the endometrium, a rare form of cancer in the lining of the uterus.
Conclusion
It has been suggested that PBs may actually represent an active biologic process that eventually results in tumour cell degeneration or death and slows the growth of the neoplasm, rather than being the result of dystrophic calcification of dead or dying tissue. It might also act as a defence against the spread of cancer.
