Rare Occurrence of Incidental Finding of Noninvasive Follicular Thyroid Neoplasm With Papillary-Like Nuclear Features in Hurthle Cell Adenoma

Abstract

Introduction:Hürthle cell adenoma is a rare benign lesion of the thyroid gland, however, controversies about its potential malignant behavior still remain. Among thyroid neoplasms, papillary carcinoma is the most common variant with great variety of histological subtypes demonstrating different biological behavior.Aim:To raise the awareness of possible coexistence of these two lesions and discussion about possible therapeutic approaches.Case report:A 42 year old female patient was examined because of the pain in the thyroid area. Cytological examination suggested Hürthle cell adenoma. Subsequently, right thyroid lobectomy was performed. Intraoperative frozen sections confirmed the diagnosis, yet final histological analysis revealed encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC), now reclassified as noninvasive follicular thyroid neoplasm with papillary- like nuclear features (NIFTP) within the adenoma, which was not noticed through scintigraphy, ultrasound, cytological and frozen section analysis.Conclusions:Problems concerning both diagnostic and therapeutic approach to these lesions are being discussed, since opinions reported in the literature are divided, posing great challenge for the clinician in determining adequate therapeutic procedures.

Clinical-pathological issues in thyroid pathology: study on the routine application of NIFTP diagnostic criteria

“…The treatment of incidental thyroid tumours is still debated: some authors suggest a conservative surgical approach while Maturo et al . suggest total thyroidectomy because these tumours are commonly multifocal and/or bilateral and show occult lymph node metastasis 26,27 . In their study, Gartland and Lubitz reported that lobectomy and total thyroidectomy yield comparable oncologic outcomes for PTC measuring 1 to 4 cm, including cases of NIFTP 28–30 .…”

First bilateral non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) co-occurring with bilateral papillary thyroid microcarcinoma. Case report and literature review

“…The published cases we reviewed exhibited variable echogenicity on US scan. Such hypoechoic, hyperechoic or isoechogenic US findings [ 11 , 14 , 16 ] are supported by others who described NIFTP lesions as well-circumscribed with widely variable echogenicity [ 14 ]. In addition, initial US only showed the left sided complex cystic nodule; only on US guided FNA was the second nodule on the right side identified and aspirated.…”

“…In terms of investigations, thyroid function tests (TFTs) are required to determine the activity of the thyroid gland. Table 1 shows that in all the cases reviewed, the patients were euthyroid indicating that the nodules were not active [ [10] , [11] , [12] , 16 ]. We are in agreement, our patient was euthyroid, although the patient had delivered around one month before the first set of TFTs which could cause unexpected endocrine fluctuations.…”

“…As for the US guided FNAC, Table 1 shows that all the cases that our review identified exhibited follicular cells in a background of colloid or benign cells. Some of the studies also found Hurthle cells [ 10 , 16 ]. In our case, FNAC of both right and left nodules showed an abundance of follicular cells in an altered architecture suggesting FLUS.…”

Synchronous Occurrence of Three Different Thyroid Tumors

“…Papillary thyroid carcinoma (PTC) represents up to 80% of all thyroid cancers. It presents several variants dominated by the classical PTC followed by the follicular variant (FVPTC) (1,2). Encapsulated FVPTC, now called noninvasive follicular thyroid neoplasm with papillary nuclear features (NIFTP) must be distinguished from follicular adenoma (FA) (1).…”