The Complementary Role of PET to Pathology in Differentiating the Primary Origin of a Malignant Skin Nodule from Liver or Lung.

Metastasis from unknown primary is always a challenge because finding the true primary tumor significantly affects subsequent management. We present a case of malignant abdominal wall nodule initially diagnosed as metastasis from hepatocellular carcinoma through excisional biopsy and immunohistochemical (IHC) staining. Dual-tracer positron emission tomography/computed tomography (PET/CT) with C-acetate and F-FDG, however, showed metabolic findings in favor of metastasis from lung origin, which was finally confirmed by ensuing a lung biopsy with additional IHC stains.

The modulation of cellular susceptibility to oxidative stress: protective and destructive actions of Cu,Zn-superoxide dismutase.

Alterations in the activity of Cu,Zn-superoxide dismutase (SOD1), an enzyme that converts superoxide (O(.-)(2)) to hydrogen peroxide (H(2)O(2)) plus O(2), have been found to affect cellular susceptibility to oxidative stress and have been invoked as a pathogenetic mechanism in a variety of neurodegenerative diseases. In apparent contradiction, some investigators have found overexpression of SOD1 to be protective whereas others have reported it to be destructive.