Metastatic thyroid carcinoma without identifiable primary tumor within the thyroid gland: a retrospective study of a rare phenomenon

Autor: R. M. Tuttle, Nora Katabi, Manju L. Prasad, Adnan Hasanovic, Perry R. Cohen, Ronald Ghossein, Bin Xu, Theresa Scognamiglio
Rok vydání: 2017
Předmět:
Adult
Male
Proto-Oncogene Proteins B-raf
0301 basic medicine
Pathology
medicine.medical_specialty
endocrine system diseases
DNA Mutational Analysis
Thyroid Carcinoma
Anaplastic
Article
Pathology and Forensic Medicine
Thyroid carcinoma
03 medical and health sciences
0302 clinical medicine
Poorly Differentiated Thyroid Carcinoma
Biomarkers
Tumor
medicine
Carcinoma
Humans
Genetic Predisposition to Disease
Thyroid Neoplasms
Anaplastic carcinoma
Aged
Retrospective Studies
business.industry
Thyroid
Cell Differentiation
Retrospective cohort study
Middle Aged
medicine.disease
Immunohistochemistry
Primary tumor
Carcinoma
Papillary
Phenotype
030104 developmental biology
medicine.anatomical_structure
Thyroid Cancer
Papillary
Lymphatic Metastasis
030220 oncology & carcinogenesis
Mutation
Neoplasms
Unknown Primary
Female
Neoplasm Grading
business
Zdroj: Human Pathology. 65:133-139
ISSN: 0046-8177
Popis: Metastatic papillary thyroid carcinoma without an identifiable primary tumor despite extensive microscopic examination of the thyroid gland is a rare but true phenomenon. We retrieved seven of such cases and described in details the clinical and pathologic features of these tumors. BRAF V600E immunohistochemistry and Sequenom molecular profile were conducted in selected cases. All patients harbored metastatic disease in the central (n = 3), lateral (n = 3), or both neck compartments (n = 1). The histotype of the metastatic disease was papillary thyroid carcinoma (PTC, n = 5), poorly differentiated thyroid carcinoma (PDTC) in association with a PTC columnar variant (n = 1), and anaplastic thyroid carcinoma (ATC) in association with a PTC tall cell variant (n = 1). Fibrosis was present in the thyroid of five patients. All patients with PTC were alive without evidence of recurrence. The 76-year-old patient with PDTC did not recur and died of unknown causes. Finally, the patient with ATC was alive with distant metastasis at last follow up. The median follow up for this cohort was 2.2 years (range 0.8 – 17). BRAF V600E was detected in 4 of 6 cases by immunohistochemistry. In conclusion, metastatic nodal disease without identifiable thyroid primary is a rare but real phenomenon of unknown mechanisms. Although most tumors are low grade and well differentiated, aggressive behavior due to poorly differentiated or anaplastic carcinoma can happen. Most cases are BRAF V600E positive thyroid tumors. A papillary carcinoma phenotype is found in all reported cases.
Databáze: OpenAIRE
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