Generally, gastric mucosal
calcinosis (GMC) is only rarely encountered in routine biopsies. GMC may be classified as dystrophic, metastatic, or idiopathic. Metastatic calcification represents the most frequently encountered subtype, and refers to the deposition of
calcium salts on largely normal tissues in the setting of an abnormal serum biochemical environment (
hypercalcemia,
hyperphosphatemia, and/or an elevated CaxPO4 product). In contrast, dystrophic calcification implies calcification in inflammed, fibrotic, or otherwise altered tissue in the setting of a normal biochemical environment. The gastric mucosa, along with the kidneys and lungs, are preferential sites for metastatic calcification, a finding that has been attributed to the relative intracellular alkalinity at these sites. In addition to the wide variety of
hypercalcemia and/or
hyperphosphatemia-causing clinical conditions, GMC has also been associated with
atrophic gastritis,
hypervitaminosis A,
organ transplantation, gastric
neoplasia,
uremia with eucalcemia/euphosphatemia, and the use of
aluminum-containing
antacids,
citrate-containing blood products,
isotretinoin, and
sucralfate. Although GMC has rarely been associated with epigastric
pain and/or
dyspepsia, most come to clinical attention owing to their accumulation of bone-seeking
radiopharmaceuticals or represent a postmortem finding. The precise significance or mechanistic basis for GMC remains to be elucidated. However, their presence in gastric biopsies should be reported, as they may serve as an
indicator for generalized metastatic calcification, especially in organs where they may be fatal, such as the heart. Furthermore, some examples of systemic calcification are reversible with normalization of biochemical parameters, which highlights the need for pathologists to report this finding when encountered in a premortem gastric biopsy.