Sections show skin with marked hyperkeratosis. The underlying dermis contains extensive, irregular, deeply basophilic, and fragmented deposits of amorphous material consistent with calcium, embedded within a dense fibrous stroma. No fungal grains, acute inflammatory microabscesses (mycetoma), or malignancy are seen.
The patient presents with a painful hyperkeratotic papule on the right foot that has been present for 8 months.
Two soft tissue fragments partially covered by skin measuring 1.5x1x0.8 cm, totally embedded.
Skin, right foot (incision biopsy):
Calcinosis cutis.
Negative for malignancy.