Postirradiation costal osteochondritis simulating metastatic cancer.

Abstract

Radiation injuries to subcutaneous tissues and underlying bones can create difficulty in differential diagnosis because their appearance may simulate metastasis or local recurrent cancer. Their recognition is important in order to avoid unnecessary surgical procedures, chemotherapy, or even reirradiation. This report will describe three cases of postirradiation osteochondritis involving the costochondral and sternoclavicular joints, simulating chest wall recurrences. Case I: A 65-year-old male, complaining of hemoptysis, was admitted to The University of California San Francisco Medical Center. A diagnosis was made of inoperable bronchogenic carcinoma, on the basis of a large right hilar mass and Class V sputum cytology. Palliative x-ray therapy, utilizing a cobalt-60 unit, was administered. In November 1964, 1,000 R was given on three consecutive days through a 9 × 7 cm right anterior field over the right hilus. After four weeks, another course of 3 times 1,000 R was given in three days to the same area. Thus, a total given dose of 6,000 R was administered in 6 treatments over a period of five weeks. In September 1965, nine months after completion of x-ray therapy, the patient was admitted to the emergency room for acute pain in the right chest and shoulder. A painful mass was felt over the irradiated right parasternal region (Fig. 1). The skin adherent to the mass was woody, wrinkled, and erythematous. X-ray films of the rib cage showed a soft-tissue mass associated with the involved costochondral joint. Although no bony destruction was evident even in the tomograms, the problem was diagnosed clinically as a metastasis. Since further x-ray therapy was contraindicated, the patient was discharged on Darvon compound. After three months, the lesion became asymptomatic; the mass did not disappear, but the skin discoloration faded. The patient was last seen on Nov. 1, 1966, free of disease. Case II: A 40-year-old female, on the basis of chest x-ray films taken in April 1965, was found to have an anterior mediastinal mass. Complete gastrointestinal studies, intravenous pyelography, mammography, and thyroid scan were reported normal. A right scalene node biopsy on May 11, 1965, revealed metastatic adenocarcinoma. At the University of California San Francisco Medical Center, initial chemotherapy was ineffective, and the patient was referred for radiation therapy in July 1965. The patient was seen by a radiotherapist in August and found to have pulmonary osteoarthropathy, as evidenced by clubbing of the fingers and swelling and pain in the left ankle and shoulder. In addition to the mediastinal mass, which had not regressed after chemotherapy, there were several metastatic subcutaneous masses. Through a single 10 × 9 cm anterior field with the cobalt-60 unit, the superior mediastinum and the left hilus were covered; doses of 1,000 R were delivered daily from Sept. 27 to 29, 1965.