Mixed connective tissue disease with fatal pulmonary hypertension.

An autopsy case of mixed connective tissue disease (MCTD) with pulmonary hypertension is presented. A 34-year-old woman suffering from arthralgia, Raynaud's phenomenon, and dyspnea of 6-years duration was diagnosed as having MCTD on the basis of a high titer (1:160,000) of serum antibody to the ribonuclease-sensitive component of extractable nuclear antigen. Examination of cardiac function revealed the complication of pulmonary hypertension. Autopsy revealed concentric intimal cellular proliferation of the small arteries and arterioles of both lungs. Typical plexiform lesions of these vessels were also observed. These findings coincide with those of plexogenic pulmonary angiopathy of primary pulmonary hypertension (PPH). This is the second autopsy case of MCTD with fatal pulmonary hypertension reported and our observations suggest that some cases with PPH who had immunological abnormalities but could not be classified as cases of classical collagen disease, may have been induced by MCTD.