[Matured mediastinal teratoma with a giant cyst resembling pleural effusion on X-ray films].

A 23-year-old man complaining of right-sided chest pain was admitted to our hospital for further examination of an abnormal shadow on chest X-ray films. Initially, we suspected the abnormal shadow was that of a pleural effusion in the right thorax. Computed tomographic scans disclosed a tumor in the anterior mediastinum, adjacent to the abnormal shadow. After closer examination, particularly by fluoroscopy on catheterization, we recognized that the abnormal shadow was a giant cyst, and that it connected with a solid mass. There were no abnormal laboratory data on admission. An examination of fluid specimens from the giant cyst revealed high levels of the tumor markers SCC antigen, CEA, and CA 19-9. These findings together suggested that the solid mass with giant cyst might be a mediastinal teratoma. The tumor was completely resectable without serious complications. The giant cyst contained 1,200 ml of fluid, and occupied half the volume of the right thoracic cavity. Pathological examination disclosed that the resected mediastinal tumor was a matured teratoma. Although matured teratoma are often composed of cysts, those that radiologically resemble pleural effusion, as in this case, were considered uncommon.

Myocardial and vascular uptake of a bone tracer associated with secondary hyperparathyroidism.

A patient on chronic hemodialysis, with secondary hyperparathyroidism was referred for a radionuclide bone-imaging study. Deposition of 99mTc-methylene diphosphonate (99mTc-MDP) was apparent in the myocardium and abdominal blood vessels, as well as in the skeleton by four-color processed scintigraphy. Plain radiographs of the chest and abdomen demonstrated no calcification in the myocardium or abdominal blood vessels. Several possible mechanism for this uptake are discussed briefly.

Accumulation of 99mTc methylene diphosphonate in malignant pleural and ascitic effusion.

Increased accumulation of radioactivity was observed in malignant pleural and ascitic effusion as to a patient with stomach cancer and in malignant pleural effusions as to 2 patients (1 with breast cancer and another with lung cancer) during the performance of routine whole-body bone scans with 99mTc methylene diphosphonate. This finding should strongly suggest malignancy.