Calcinosis is the formation of calcium deposits in any soft tissue. It is a rare condition that has many different causes. These range from infection and injury to systemic diseases like kidney failure. Types
Dystrophic calcification
The most common type of calcinosis is dystrophic calcification. This type of calcification can occur as a response to any soft tissue damage, including that involved in implantation of medical devices. Metastatic calcification
Metastatic calcification involves a systemic calcium excess imbalance, which can be caused by hypercalcemia, kidney failure, milk-alkali syndrome, lack or excess of other minerals, or other causes. Tumoral calcinosis
The cause of the rare condition of tumoral calcinosis is not entirely understood. It is generally characterized by large, globular calcifications near joints. See also
Calcification
Calcinosis cutis
Dermatomyositis
Fahrs syndrome
Hyperphosphatemia
Primrose syndrome
Scleroderma

References
External links
 Media related to Calcinosis at Wikimedia Commons
Classification
There is substantial debate regarding histopathologic classification of pseudomyxoma peritonei. In 1995, Ronnett et al. proposed separating pseudomyxoma peritonei cases into two diagnostic categories: adenoma (disseminated peritoneal adenomucinosis, DPAM) or carcinoma (peritoneal mucinous carcinomatosis, PMCA) with a third category reserved for cases with intermediate features. In this classification system, cases of DPAM were characterized by peritoneal lesions composed of abundant extracellular mucin containing scant simple to focally proliferative mucinous epithelium with little cytologic atypia or mitotic activity (in other words, most cells looked fairly normal and there was no evidence of mitosis which would indicate that cells were rapidly dividing), with or without an associated appendiceal mucinous adenoma. Cases of PMCA were characterized by peritoneal lesions composed of more abundant mucinous epithelium with the architectural and cytologic features of carcinoma (irregular cells, evidence that cells were rapidly dividing, and other criteria), with or without an associated primary mucinous adenocarcinoma. Bradley et al. (2007) argued that continued use of non-malignant terms, i.e., adenoma, for those frequent cases with low-grade features (such as DPAM), is misleading because pseudomyxoma peritonei is a disease state that results from invasion of the abdominal cavity by cells with uncontrolled growth. Bradley states that an adenoma, by definition, is a tumor confined to the appendiceal mucosa with absolutely no evidence of invasion beyond the muscularis mucosae. The term mucinous adenocarcinoma is used in different contexts depending on the reference material used by the pathologist for disease classification.