Calcinosis circumscripta on lingual muscles and dermis in a dog

Abstract

A 10-month old male Shi-tzu was presented with a week history of scurfy skin and whitish masses located in the ventral portion of tongue. Grossly, two whitish prominences with diameters of 3 to 4 mm were found on the underside of the tongue. Microscopically, in ulcerative epidermis, deposition of dense, amorphous granular basophilic calcium salts was separated by thin fibrous connective tissue containing mild inflammation. Many fascicles were characterized by replacement of degenerating myofibers with calcification. The precise cause of calcification could not be determined; however, it is interesting that two different lesions shown in calcinosis circumscripta and slight nutritional myopathy were also observed simultaneously only in the tongue.