title: Transformation of Merkel cell carcinoma to ganglioneuroblastoma in intracranial metastasis.
abstract: Merkel cell carcinoma is an aggressive neuroendocrine tumor occasionally demonstrating aberrant differentiation to other epithelial and nonepithelial cell lines. We describe a case of Merkel cell carcinoma displaying unique patterns of differentiation in the primary focus and brain metastasis. The skin primary was almost uniformly small cell carcinoma positive for epithelial and neuroendocrine markers, with a few glial fibrillary acidic protein- and cytokeratin 20-positive cells. The neoplasm contained giant cells immunoreactive for neurofilament and negative for epithelial markers. The neck lymph node metastasis was a typical neuroendocrine Merkel cell carcinoma positive for cytokeratin 20. A solitary dural intracranial metastasis displayed features of aggressive ganglioneuroblastoma, expressing many neuronal antigens with no evidence of glial or epithelial differentiation. After total gross resection, the tumor recurred within 3 months, and the patient developed skeletal metastases and died 6 months after craniotomy.
authors.affiliation: Department of Pathology & Molecular Medicine, Hamilton General Hospital and McMaster University, Hamilton, Ontario, Canada, L8L 2X2. Electronic address: lach@hhsc.ca.
authors.forename: Boleslaw
authors.initials: B
authors.lastname: Lach
authors.affiliation: Greater Niagara General Hospital, Niagara Health System, Niagara Falls L2E 6X2, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Sangeeta S
authors.initials: SS
authors.lastname: Joshi
authors.affiliation: Department of Neurosurgery, Hamilton General Hospital and McMaster University, Hamilton, Ontario, Canada, L8L SG8.
authors.forename: Naresh
authors.initials: N
authors.lastname: Murty
authors.affiliation: Greater Niagara General Hospital, Niagara Health System, Niagara Falls L2E 6X2, McMaster University, Hamilton, Ontario, Canada; Clinical Surgery, McMaster University, Hamilton, Ontario, Canada, L2G S24.
authors.forename: Nasimul
authors.initials: N
authors.lastname: Huq
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D001859:Bone Neoplasms / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D001932:Brain Neoplasms / Q000556:secondary* / Q000601:surgery; D015266:Carcinoma, Merkel Cell / Q000556:secondary* / Q000601:surgery; D018288:Carcinoma, Small Cell / Q000556:secondary* / Q000601:surgery; D002471:Cell Transformation, Neoplastic; D017809:Fatal Outcome; D018305:Ganglioneuroblastoma / Q000556:secondary* / Q000601:surgery; D015726:Giant Cells / Q000378:metabolism; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D053554:Keratin-20 / Q000378:metabolism; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D009364:Neoplasm Recurrence, Local; D016900:Neurofilament Proteins / Q000378:metabolism; D012878:Skin Neoplasms / Q000473:pathology* / Q000601:surgery
chemical_list: D014408:Biomarkers, Tumor; D005904:Glial Fibrillary Acidic Protein; D053554:Keratin-20; D016900:Neurofilament Proteins
keywords: Brain metastases; Dural metastases; Ganglioneuroblastoma; Merkel cell carcinoma; Neuroendocrine tumors