A thoracic benign mesenchymoma in association with hemihypertrophy.

A thoracic benign mesenchymoma was removed from an 18-year old caucasian male who also had hemihypertrophy. The very large benign mesenchymoma which was removed was found to consist of an admixture of cytologically mature vascular spaces, adipose tissue, and smooth muscle. After removal of the tumor, the patient has had no recurrence with one year of follow-up. Patients with hemihypertrophy appear to be at high risk to develop neoplasms. Malignant neoplasms of the adrenal gland, kidney, and liver are most common. It is suggested that patients with hemihypertrophy should be followed periodically for their entire life because of their propensity to develop tumors.