[A case of increased 123I-IMP uptake in adenocarcinoma of the lung]

It has been reported that delayed 123I-IMP lung scintigraphy shows a defect corresponding to the tumor with increased accumulation around the tumor, and that an increased accumulation is associated with atelectasis and inflammation. We presented a case of increased uptake of 123I-IMP in lung cancer. None of the other reported case of increased uptake in lung cancer, to our knowledge, occurred. A 55-year-old man had a 6 cm mass in the lower lobe of the right lung. Cytologic examination with a small curette diagnosed the case as an adenocarcinoma. The 123I-IMP scintigraphy was performed 24 hours after intravenous injection of 111 MBq of 123I-IMP. The 123I-IMP SPECT lung images showed an area of increased 123I-IMP concentration corresponding to the tumor mass. The patient's subsequent course was characterized by massive pleural effusion caused by extensive invasion to the pleura despite chemotherapy. He died about 2 months after the 123I-IMP scintigraphy. The right lung removed at necropsy confirmed that the area of high 123I-IMP concentration corresponded to the mass, which proved a poorly differentiated adenocarcinoma. One should note that there is an unusual case with high 123I-IMP uptake in lung cancer.