Paraneoplastic neurologic syndrome associated with small breast cancer: diagnostic value of FDG-PET for detection of underlying malignancy.

摘要

A 67-year-old female was admitted in June 2004 because of diplopia and progressive muscle weakness of the right upper and lower limbs with an ataxic gait for over a month. While the physical examination, laboratory tests and chest roentgenogram were normal, brain MRI showed high-signal lesions in the dorsal pons and left temporal lobe on FLAIR images (Fig. 1 A). Cerebrospinal fluid studies showed a cell count of 5/mm3 and elevated total protein and IgG levels (48 mg/dl and 9.7 mg/dl). Paraneoplastic syndrome was strongly suspected because of her progressive clinical course and brain MRI findings. An FDG-PET scan was, therefore, performed and revealed a hot spot in the left breast (Fig. IB), where a small mass was subsequently shown on a chest CT (Fig. 1C). Histopathological examination of the completely resected tumor demonstrated papillotubular adenocarcinoma. Afterward, anti-Ri antibody was detected in her serum and a definite diagnosis of paraneoplastic syndrome was made. The FDG-PET might be of great use in detecting an underlying malignancy in patients with paraneoplastic neurological disorders.