- Clinically, the disease is divided into 2 major subsets, diffuse cutaneous SSc (dcSSc) and limited cutaneous SSc (lcSSc). The diffuse cutaneous subtype is generally associated with significant internal organ involvement, especially renal crisis and diffuse alveolitis of the lung, along with antitopoisomerase (antitopo) autoantibody. The limited cutaneous subtype is distinguished by Raynaud's phenomenon, telangiectasias, pulmonary hypertension, and the presence of anticentromere antibody. However, there is significant overlap both in the clinical manifestations and in the specific autoantibodies that occur in these subtypes. It is not known what predisposes a susceptible individual to develop one subtype versus another, nor is there significant information about how the 2 disease subtypes may be pathogenically related.