The use of core needle biopsy as first-line in diagnosis of thyroid nodules reduces false negative and inconclusive data reported by fine-needle aspiration.

BACKGROUND: The reported reliability of core needle biopsy (CNB) is high in assessing thyroid nodules after inconclusive fine-needle aspiration (FNA) attempts. However, first-line use of CNB for nodules considered at risk by ultrasonography (US) has yet to be studied. The aim of this study were: 1) to evaluate the potential merit of using CNB first-line instead of conventional FNA in thyroid nodules with suspicious ultrasonographic features; 2) to compare CNB and FNA as a first-line diagnostic procedure in thyroid lesions at higher risk of cancer. METHODS: Seventy-seven patients with a suspicious-appearing, recently discovered solid thyroid nodule were initially enrolled as study participants. No patients had undergone prior thyroid fine-needle aspiration/biopsy. Based on study design, all patients were proposed to undergo CNB as first-line diagnostic aspiration, while those patients refusing to do so underwent conventional FNA. RESULTS: Five patients refused the study, and a total of 31 and 41 thyroid nodules were subjected to CNB and FNA, respectively. At follow-up, the overall rate of malignancy was of 80% (CNB, 77%; FNA, 83%). However, the diagnostic accuracy of CNB (97%) was significantly (P < 0.05) higher than that of FNA (78%). In one benign lesion, CNB was inconclusive. Four (12%) of the 34 cancers of the FNA group were not initially diagnosed because of false negative (N = 1), indeterminate (N = 2) or not adequate (N = 1) samples. CONCLUSIONS: CNB can reduce the false negative and inconclusive results of conventional FNA and should be considered a first-line method in assessing solid thyroid nodules at high risk of malignancy.

Thin core biopsy should help to discriminate thyroid nodules cytologically classified as indeterminate. A new sampling technique.

Indeterminate neoplasms (IN) represent the gray zone of thyroid cytology in which malignant and benign tumors cannot be discriminated. Recently, the approach by thin core needle biopsy has been proposed. Here we report a new thin core needle biopsy approach in 40 consecutive patients with thyroid IN at cytology. In this study, a 21-G needle was inserted into the nodule, advanced within the lesion, and moved ahead reaching extranodular tissue. The resulting sample allowed to evaluate the cytomorphology of nodular tissue, its relationship with extranodular parenchyma, and the nodule's capsule when present. All biopsies were adequate for diagnosis but one. Of the 39 adequate samples, 5 cases were papillary cancer as confirmed at histology, while 14 nodules avoided surgery because of Hürthle cell hyperplasia in thyroiditis (n = 6) and microfollicular adenomatous hyperplasia (n = 8). The remaining 20 cases were assessed as follicular neoplasms because of encapsulation and were evaluated by immunohistochemistry. Of these, 6 had positive markers in different degree and 1/6 has follicular cancer at histology, while the other 14 were benign after surgery. Overall, this approach by thin core needle biopsy identified benignancy in 14/40 (35 %) IN avoiding surgery. As a conclusion, thin core biopsy should help to discern the nature of thyroid lesions cytologically classified as indeterminate, and it should be used as a complementary test in thyroid nodule assessment.