Accumulation of Tc-99m HMDP in bony structures of immature teratoma in a child.

A 6-year-old girl with a large abdominal tumor had Tc-99m HMDP bone scintigraphy to identify possible bone metastases. Her α-fetoprotein level was 138 ng/ml (normal, <10 ng/ ml) and carbohydrate antigen-125 (CA-125) value was 460 U/ml (normal, <35 ml). Computed tomography showed a huge lower abdominal mass with mottled contrast enhancement, cystic regions, and bone-like calcified regions. Whole-body imaging showed scattered radionuclide accumulation in the abdomen, and SPECT imaging clearly revealed that the accumulation existed in the calcified area of the tumor. At surgery, an immature left ovarian teratoma (grade 1) was found accompanied by glial peritoneal implants and a small amount of ascites. Intratumoral bone was found.