A case of tumor calcinosis with unusual cutaneous lesions occurred. The skin lesions were calcified and widespread, occurring particularly on flexural surfaces. Many of these lesions were unrelated to the large subcutaneous calcified masses, characteristic of this condition, which were situated largely over extensor or exposed surfaces. The patient was investigated extensively, and the histopathology of the dermal and subcutaneous lesions is recorded. To our knowledge no patient with similar skin lesions appears previously to have been reported. The histological appearances of these lesions lead to the suggestion that an inherited fault of collagen tissue is the primary defect in this disease.