Scintigraphic differentiation of congenital soft-tissue extremity enlargement with Tc-99m DTPA.

Radionuclide imaging of benign soft-tissue tumors sometimes associated with extremity enlargement (7 patients) and/or osteodysplasia (6 patients) has demonstrated, in a total of 18 patients, several differentiating patterns of accumulation of Technetium-99m diethylene triamine pentaacetic acid (Tc-99m DTPA). Early imaging (within 15 min) as well as later imaging (one-half hour to 3 hours following the intravenous injection of the radiopharmaceutical) has shown that fatty tumors (lipomas, lipoblastomas, fibrofatty tissue) do not concentrate the isotope. Neurofibromas display gradual intensification of their radioactive content, while hemangiomas differ in their scintigraphic pattern depending on their histologic composition. Purely capillary hemangiomas have transient early intense activity while purely cavernous hemangiomas display no early activity but are well visualized on delayed scintigraphic images. Mixed hemangiomas display combined imaging characteristics of both capillary and cavernous types with the predominant pattern dependent upon the predominant histology. Aggressive fibromatosis exhibited an early fleeting display of intense radioactivity.