31-P mr spectroscopy of a leg lymphangiosarcoma

In a 64 year old man with a large, low grade lymphangiosarcoma of the right thigh, we correlated the results of in vivo 31-P-magnetic resonance spectroscopy (MRS), proton magnetic resonance imaging (MRI), and digital subtraction (DSA) with the pathologic specimen and histology. The 31-P MRS spectra of the tumor showed well-resolved peaks as follows: intense PCr (phosphocreatine), PDE (phosphodiester) and Pi (inorganic phosphate), and low PME (phosphomonoester). The Pi peak revealed an intratumor pH of 6.96 compared with 7.16 of normal skeletal muscle. The lower PME signal was consistent with low histopathologic mitotic activity of the tumor.