Total thyroidectomy for the treatment of Hashimoto's thyroiditis coexisting with papillary thyroid carcinoma.
ABSTRACT The coexistence of Hashimoto's thyroiditis (HT) and papillary thyroid carcinoma (PTC) is controversial. This study was conducted to evaluate the correlation between HT and PTC and to identify predictive factors for the coexistence of PTC and HT. A total of 922 patients underwent surgery for thyroid disorders between January 2001 and August 2005. In all, 199 patients had been diagnosed with PTC, 37 of whom had coexistent HT; in 689 patients, benign thyroid disease had been diagnosed. Patients' age and sex, as well as histopathology, tumor size, nodal involvement status, multicentricity, presence of metastasis, and serum thyroglobulin levels, were retrospectively reviewed. A significant correlation was observed between HT and PTC, although no statistical significance was noted between PTC and HT type (nodular or diffuse). Most patients with PTC+HT were female and younger (<40 y old) than those with PTC only. The rate of occult tumor in patients with PTC+HT was higher than that in patients with PTC alone. Data indicate the coexistence of PTC and HT and suggest that PTC may develop even in cases of diffuse HT. Total thyroidectomy is the surgical procedure of choice, especially in young, female patients with HT.
Article: Absence of BRAF, NRAS, KRAS, HRAS mutations, and RET/PTC gene rearrangements distinguishes dominant nodules in Hashimoto thyroiditis from papillary thyroid carcinomas.[show abstract] [hide abstract]
ABSTRACT: Dominant nodules within Hashimoto thyroiditis (HT) may present with unique morphological features that overlap with but are not diagnostic of papillary thyroid carcinoma (PTC). Activating BRAF point mutations, RAS aberrations, and RET rearrangements are mutually exclusive events in the oncogenesis of papillary thyroid carcinoma, and RET rearrangements have been previously described in dominant nodules of HT. We identified 28 cases of Hashimoto thyroiditis with a dominant nodule, from 345 consecutive HT thyroidectomies. Screening for BRAF, RET, KRAS, NRAS, and HRAS mutations, as well as RET-PTC1 and RET-PTC3 rearrangements, was performed on paraffin-embedded material from 17 of these dominant nodules. Patients ranged in age from 29 to 76 years and were predominantly female, and the nodules ranged from 1.5 to 6.2 cm. No BRAF or RAS mutations or RET-PTC rearrangements were identified in a dominant nodule, including those with atypical, worrisome histopathologic features. Of ten cases with diagnostic concomitant or incidental papillary carcinoma, three had a V600E point mutation in BRAF, and one case had a BRAF exon 15 deletion (600-604E), while the dominant nodules were negative for mutation, supporting the notion that dominant nodules are neither malignant nor precursor lesions, and strict histological, clinical, and molecular criteria must be met for the diagnosis of papillary thyroid carcinoma.Endocrine Pathology 12/2009; 21(2):73-9. · 1.36 Impact Factor