title: Cytokeratin 20 confirms merkel cell metastasis to stomach.
abstract: Merkel cell carcinoma (MCC) is an uncommon, aggressive neuroendocrine carcinoma of the skin. Its prognosis is poor because of involvement of regional lymph nodes and metastases to distant sites such as bone, liver, lung, and brain. Very few metastases are reported to the gastrointestinal tract. Several studies have shown the utility of cytokeratin 20 to differentiate MCC from other small round blue cell tumors, particularly those with neuroendocrine differentiation. In this case report, we present an unusual metastasis to the stomach and the utility of cytokeratin 20 immunohistochemistry to confirm MCC.
authors.affiliation: Department of Pathology, University of Florida College of Medicine, Gainesville, FL, USA. limk@pathology.ufl.edu
authors.forename: Melissa
authors.initials: M
authors.lastname: Li
authors.forename: Chen
authors.initials: C
authors.lastname: Liu
mesh_terms: D015266:Carcinoma, Merkel Cell / Q000473:pathology*; D003937:Diagnosis, Differential; D005753:Gastric Mucosa / Q000276:immunology / Q000473:pathology; D006801:Humans; D007381:Intermediate Filament Proteins / Q000032:analysis*; D053554:Keratin-20; D008297:Male; D018862:Merkel Cells / Q000473:pathology; D008875:Middle Aged; D012867:Skin / Q000276:immunology / Q000473:pathology; D012878:Skin Neoplasms / Q000473:pathology*; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000556:secondary*
chemical_list: D007381:Intermediate Filament Proteins; C507499:KRT20 protein, human; D053554:Keratin-20