Mediastinal neurilemmoma demonstrated by positive Tc-99m(V) DMSA SPECT and negative Ga-67 uptake.

Schwannoma is a benign neurogenic tumor arising from the sheath of a peripheral nerve. Tc-99m(V) DMSA, developed by Yokoyama et al. in 1981, has been recognized as advantageous for the scintigraphic diagnosis of various malignant tumors and their metastases. Uptake of Tc-99m(V) DMSA was seen not only in malignant tumors but also in benign lesions. Tc-99m(V) DMSA has been reported to accumulate in soft-tissue tumors, such as neurofibromatomas and Schwannomas. In the current report, the authors describe uptake of Tc-99m(V) DMSA in a mediastinal neurilemmoma, but not Ga-67, which is very useful in suggesting the nature of the tumor.