A 40-year-old woman who experienced progressive right abdominal pain for 1 month was admitted to our hospital. The patient and her family members were diagnosed with Carney complex (CNC). Two years prior to admission, the patient underwent percutaneous needle biopsy of a newly diagnosed intercostal mass near segment V of the liver by computed tomography (CT) (Fig. 1A) and biopsy suggested the presence of psammomatous melanotic schwannoma (PMS). At admission, CT images showed a 3.9 × 1.5 cm mass with ill-defined (Fig. 1B). The size of the mass increased by 1.9 cm in 2 years, and newly occurring calcification was present. Laparoscopic tumor resection was performed. The tumor biopsy revealed a distinct transition between the hypercellular epithelioid central and hypocellular spindle peripheral zones (Fig. 1C), together with the melanin-containing spindle cells and psammoma bodies, stained positively for HMB45 (Fig. 1D). Based on positive staining for S-100 protein (Fig. 1E), and vimentin, the tumor was diagnosed as a malignant PMS. The 2-[fluorine-18]-fluoro-2-deoxy-D-glu-cose-positon emission tomography/CT (FDG-PET/CT) performed at the initial diagnosis of PMS, showed no significant FDG uptake (Fig. 2A); however, at admission, intense FDG uptake in the intercostal mass was observed (Fig. 2B). Approximately 3 years after the diagnosis of PMS, the patient suffered from tumor growth and distant metastasis (Fig. 2C-2G), and died despite adjuvant chemotherapy and radiotherapy.