Evaluation of Accuracy of One-Step Nucleic Acid Amplification (OSNA) in Diagnosis of Lymph Node Metastases of Papillary Thyroid Carcinoma
Evaluation of Accuracy of One-Step Nucleic Acid Amplification (OSNA) in Diagnosis of Lymph Node Metastases of Papillary Thyroid Carcinoma
The incidence of node metastases in papillary thyroid carcinoma (PTC) is high, ranging from
 20% to 90%. Prophylactic central lymph node compartment dissection (CLND), suggested from the
 latest guidelines for high-risk tumors, meets resistance due to the high incidence of
 postoperative complications. Recently, new molecular biologic techniques, such as One Step
 Nucleic Acid Amplification (OSNA), have spread widely, allowing to quickly isolate, amplify
 and quantify mRNA encoding for proteins selectively present in neoplastic cells, as
 Cytokeratine-19. The aim of this study is to evaluate the application of OSNA to
 intraoperative diagnosis of node metastases of PTC.
Papillary thyroid carcinoma (PTC) is the most common malignant thyroid neoplasm; it
 originates from follicular cells of thyroid gland, and represents over 80% of thyroid tumors.
 The incidence of PTC has progressively been increasing in the last decades, doubling since
 the 1970s, due to the diffusion of screening ultrasound. Although PTCs are considered
 slow-growing tumors, the incidence of node metastases is high, ranging from 20% to 90%. The
 real impact of node metastases on prognosis is still a matter of debate: reports in
 literature demonstrate a reduction of disease-free survival but are divergent on overall
 survival. Diagnostic tools have poor accuracy for central lymph node compartment, which is
 the most frequent site of metastases.

 The last guidelines suggest a prophylactic central lymph node compartment dissection (CLND)
 in patients with high-risk PTC; nevertheless, this indication meets resistance due to the
 higher incidence of postoperative complications, especially hypoparathyroidism and recurrent
 laryngeal nerve (RLN) palsy.

 Recently, new molecular biologic techniques have spread widely, mainly in diagnosis of node
 metastases in breast carcinoma; these assays allow to quickly isolate, amplify and quantify
 mRNA encoding for proteins selectively present in neoplastic cells, as Cytokeratine-19
 (CK-19). One Step Nucleic Acid Amplification (OSNA) is routinely used in diagnosis of node
 metastasis in sentinel lymph node (SNL) of patients affected from breast cancer. The aim of
 this study is to evaluate if application of OSNA to intraoperative diagnosis of node
 metastases of PTC is possible.
Inclusion Criteria:

 Preoperative diagnosis of thyroid carcinoma

 Exclusion Criteria:

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