Calcinosis is defined as the pathological accumulation of calcium deposits in various structures, including the skin, the tissue subcutaneously, the muscle fascia, and the organs neoplasms. The most frequent are those of the gastrointestinal tract, especially when they occur in the context of the. When this manifestation primarily affects the dermal layer, it is called calcinosis cutis or, more specifically, calcificación cutaneous.

Detailed Histopathology of Calcinosis Cutis

From a histological perspective, calcinosis cutis is characterized by the presence of acellular deposits that exhibit an intense affinity for basophilic stains, distributed heterogeneously within the dermis and surrounding connective tissue (see Figure 1). This basophilia is notably strong, resulting in a very pronounced purple coloration in standard stains (Figures 2 and 3).

Typically, these calcified deposits are well demarcated and often present a thin border composed of eosinophilic suggesting hyalinization. It is also common to observe an adjacent inflammatory reaction with the presence of macrophages and giant host cells or foreign body cells host cells.

A frequent artifact during histological processing is the fracturing of the calcified material and adjacent tissue, which produces artifactual lines visible in the section (Figure 1), slightly hindering morphological interpretation.

Specialized Histological Study Techniques

To confirm and differentiate calcium salts from other basophilic structures, special stains are used. Von Kossa silver stain is particularly useful, as it highlights mineral deposits with a characteristic black coloration (see Figure 4 for its application in calcinosis cutis).

Performing a Differential Diagnosis of Calcinosis Cutis

To establish an accurate diagnosis of calcinosis cutis, it is essential to differentiate it from other skin conditions that present mineral or nodular deposits. This distinction is primarily based on the histopathological analysis of the samples.