Calcinosis circumscripta associated with surgical site of the right femur in a Belgian sheepdog: imaging diagnosis and surgical treatment

Abstract

A nine-month, intact male, Belgian Sheepdog was presented to the hospital due to a history of rapidly progressive growth of a solitary calcified mass at the right hip area. The dog has a history of an internal implant fixation for the right femoral fracture at 5 months ago. Physical examination revealed a dome shape, hard consistency, non-movable, painless, subcutaneous mass with size 5x6 cm. Radiography and ultrasonography showed a well-circumscribed, calcified soft tissue mass at craniolateral aspect of the right proximal femur without cortical bone reaction. Computed tomography (CT) scan was not performed in this case because metal fixation was implanted at the right femur. Cytology was obtained by the fine needle aspiration which revealed numerous transplant unstained granular crystals material with few neutrophils and macrophage. Whereas blood profile revealed normal ranges of serum calcium, phosphorus and parathyroid hormone levels. Surgical excision was subsequently done to remove the calcified mass. On the gross, cross section of the calcified mass revealed variable sizes of chalky-like appearance that accumulated in the dermis and epidermis. In addition, the calcified lesion also extended into the underlying skeletal muscle. The mass was finally diagnosed to be calcinosis circumscripta with the positive staining with Von Koss. After 4 months post-operative monitoring, no evidence of recurrence calcinosis circumscripta at the corrected surgical site.