Nucl Med Mol Imaging.  2023 Feb;57(1):38-43. 10.1007/s13139-022-00777-z.

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

• Ho I
• Chen S
• Yip Y
• Ho C

• KMID: 2539528
• DOI: http://doi.org/10.1007/s13139-022-00777-z

Abstract

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 11 C-acetate and 18 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. This case illustrates the complementary molecular role of PET to pathology, particularly when dual-tracer or multi-tracer PET is used in conjunction with pathology methods for cross referencing and confirmation.

Keyword

IHC; Dual-tracer PET/CT; HCC; CA lung