Hematoporphyrin derivative in the detection and localization of radiographically occult lung cancer.

Hematoporphyrin derivative used in conjunction with the Mayo Clinic bronchofiberscopic fluorescence detection system allows accurate localization of radiographically occult early squamous cell carcinoma. Thirteen tumors were localized in 10 patients with radiographically occult lung cancer. Six were in situ with or without microinvasion and were also bronchoscopically occult. Localization of these 6 tumors was expedited by the use of hematoporphyrin derivative and the bronchoscopic fluorescence detection system. Hematoporphyrin-derivative fluorescence was not specific for carcinoma and was also detected in areas of moderate and marked squamous cellular atypia. Thus, although detection of hematoporphyrin-derivative fluorescence suggests the presence of cancer, proof depends on histologic or cytologic confirmation.