Giant Malignant Phyllodes Tumor with &sup99m;Tc-Sestamibi Accumulation: Report of a Case.

We report a case of a giant malignant phyllodes trmor examinde by &sup99m; Tc-sestamibi (MIBI) mammoscintigraphy. The patient was a 51 yera-old woman who complainedof bleeding from a large mass in her right breast. The tumor was well circumscribed, with an ulcerized surface. The accumulation of &sup99m; Tc-MIBI in the tumor was recognized on &sup99m; Tc-MIBI scintigraphy. A standard radical mastectomy was performed with a wide margin of skin. The resected specimen measured 20x17x13cm, weighed 2100g and was histologically diagnosed as a malignant phyllodes tumor. The skin defect was reconstructed by a rectus abdominis musculocutaneous flap, with good cosmetic results. &sup99m; Tc-MIBI scintigraphy may have the potential to distinguish a malignant from benign phyllodes tumors.