Ultrasound findings of noninvasive follicular thyroid neoplasm with papillary-like nuclear features compared with those of follicular variant of papillary carcinoma and encapsulated papillary carcinoma: a single-institution study in Japan.

Noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) is a new entity adopted by the newest World Health Organization classification. It is differentiated from follicular variant papillary thyroid carcinoma (FVPTC) and regarded as non-malignant disease. Here, we compared the ultrasound findings of NIFTP (n = 40) with those of FVPTC (n = 94) and encapsulated PTC (encap-PTC) (n = 157). The NIFTP group showed benign findings on ultrasound significantly more frequently than the FVPTC group based on the Japan Society of Ultrasonics in Medicine criteria: a regular shape (p < 0.001), well edge definition (p = 0.007), smooth character (p < 0.001), isoechoic and homogeneous internal echoes (p < 0.001), lack of punctate microcalcification (p = 0.027), and a regular marginal hypoechoic zone (p < 0.001). Compared to encap-PTC, NIFTP has a significantly higher incidence of benign findings: isoechoic and homogeneous internal echoes (p < 0.001), lack of punctate microcalcification (p < 0.001), and a regular marginal hypoechoic zone (p = 0.004). Based on the ultrasound classification (USC) system at Kuma Hospital, no cases were classified as malignant (USC ≥3.5), but 55.4% of the FVPTCs and 53.5% of the encap-PTCs were diagnosed as malignancy. However, on cytology, the incidence of NIFTP classified as Bethesda-V or -VI (PTC) was very high at 86.9%. All patients underwent surgical treatment, but none of the NIFTP patients showed postoperative recurrence. Although avoiding surgery might be difficult because of the high incidence of malignant cytology, overtreatment (including extensive surgery) for NIFTP can be avoided by paying close attention to the lack of malignant findings on ultrasound.

Case report: exceptionally rapid growth character of hobnail variant of papillary thyroid carcinoma: a report of four cases.

The newest WHO classification adopts hobnail variant as an aggressive variant of papillary thyroid carcinoma (PTC). We here report four cases (ages 70-76 years, all females) with hobnail variant PTC treated at Kuma Hospital. Their lesions were cytologically diagnosed as PTC before surgery, but not as hobnail variant. All patients underwent a total thyroidectomy with central node dissection, and two patients also underwent therapeutic lateral node dissection. The clinical courses of three of the patients were very eventful. One patient showed recurrence to lymph nodes in the lateral compartment only 5 months after the initial surgery. In the initial surgery, one patient had a 36-mm lymph node metastasis in the lateral compartment, which was diagnosed as hobnail variant on pathology; 9 months post-surgery, metastases to the ipsilateral lateral lymph node, lung, and bone were newly detected. Her lung metastasis grew rapidly; its tumor volume-doubling time was 0.15 years and its tumor-doubling rate was 6.67/year. One patient underwent annual ultrasound examinations as postoperative follow-up after hemithyroidectomy for a benign nodule, but a 35-mm nodule diagnosed as PTC on cytology and lateral node metastases appeared within a short period, and she underwent a second surgery. Both the primary lesion and lymph nodes were diagnosed as hobnail variant by postoperative pathology. Three of the four patients showed exceptionally rapid growth of primary and/or metastatic/recurred lesions, indicating that patients with the hobnail variant should undergo very close and careful post-operative observation.

Thyroid Lymphoepithelial Cysts Mimicking Calcified or Solid Nodules on Ultrasonography.

PURPOSE: Thyroid lymphoepithelial cysts (TLECs) are rare, and detailed ultrasonography (US) findings have not been reported. This study aimed to examine in detail the US findings for 32 TLECs and to clarify the diagnostic problems associated with them. MATERIALS AND METHODS: We examined 32 TLECs resected from 21 patients at the Kuma hospital between January 2008 and April 2018. All patients underwent US before resection. From the patients' medical records, we retrospectively assessed US reports and photographs of TLECs. RESULTS: The following four types of TLECs were classified: cystic, mixed solid and cystic, pseudo-solid, and pseudo-calcified types. The incidences were 50.0%, 12.5%, 12.5%, and 25.0%, respectively. Among the four types, pseudo-calcified TLECs were the smallest in size (mean: 7.1 mm). Of 24 nodules that had been interpreted in US reports, 11, 9, 1, 2, and 1 were benign, very low, low, intermediate, and high, respectively. Calcification and intramural solid growth were not identified by histological examination. CONCLUSION: We should be aware that approximately half of TLECs do not exhibit US appearances typical of simple cysts, and TLECs may mimic calcified or solid nodules on US, although the reason remains unknown.

Can Ultrasound Alone Predict Papillary Thyroid Carcinoma with Desmoid-Type Fibromatosis? A Retrospective Analysis of 13 Cases, Focusing on the Stromal Area.

PURPOSE: Papillary thyroid carcinoma with desmoid-type fibromatosis (PTC-DTF) is extremely rare. So far, only 4 cases describing the ultrasound findings of this variant have been reported. Here, we describe the ultrasound findings of 13 cases of PTC-DTF, focusing especially on the DTF area. MATERIALS AND METHODS: We retrospectively analyzed the clinical reports, ultrasound reports, and ultrasound photographs obtained from medical records at Kuma Hospital. RESULTS: The patients included 8 women and 5 men with a mean age of 47.9 years. The widest dimension of the nodules ranged from 16 to 79 mm (mean: 37.5 mm). The original ultrasound reports classified the nodules as either intermediate suspicion or high suspicion. A diagnosis of PTC was suspected in 12 nodules, and anaplastic carcinoma was suspected in 1 nodule. PTC-DTF presented with an irregularly shaped nodule (100%), taller-than-wide sign (84.6%), heterogeneous echogenicity (100%), no microcalcification (76.9%), and no or mild flow signal on Doppler (75.0%). The DTF area was identified in the ultrasound photographs of 8 nodules. DTF areas were generally heterogeneous (62.5%) and more hypoechoic (71.4%) than PTC areas. Microcalcification was not observed in the DTF areas. All of the DTF areas revealed no or mild flow signal. On ultrasound elastography, the DTF areas were not stiff, and they were more elastic than the PTC areas. CONCLUSION: It is difficult to predict PTC-DTF using ultrasound alone, and B-mode ultrasonography is more reliable than ultrasound elastography in the ultrasound diagnosis of malignant thyroid nodules.

Phantom Nodules Detected by Ultrasound Examination of the Neck: The Possibility of Ectopic Cervical Thymic Tissue in Adults.

PURPOSE: The aim of this study was to investigate the ultrasound characteristics and clinical significance of slightly hyperechoic lesions, referred to as phantom nodules, in the perithyroidal area in patients. MATERIALS AND METHODS: A total of 128 patients who underwent thyroidectomy with central neck lymph node dissection at Kuma Hospital in Hyogo, Japan were included in the study. We detected 16 phantom nodules during preoperative ultrasound examinations, defined as slightly hyperechoic masses located in the perithyroidal areas, in 13 of these 128 patients (10.2%; mean age: 55.6 years, range: 36-75 years). RESULTS: All phantom nodules were located in the caudal region of the thyroid gland, and the mean maximum dimension was 7.2 mm. 12 of the 16 nodules were round or oval, while the remaining 4 were fusiform and molded by the surrounding tissue. All nodules were well-defined, solid, homogeneous, hyperechoic masses. No speckled echo pattern, internal linear echo, or vascular flow signal was observed. All 4 nodules subjected to histological examination were composed of ectopic thymic tissue. In 2 of these 4, the parenchyma was severely involuted and almost entirely replaced by adipose tissue. CONCLUSION: To the best of our knowledge, this is the first report wherein some of the detected hyperechoic perithyroidal masses were composed of ectopic thymic tissue, and some were primarily composed of adipose tissue that completely replaced involuted ectopic thymic tissue. The results of the study suggest that these so-called phantom nodules are clinically insignificant and do not require fine needle aspiration cytology or further investigation.

Re-Evaluation of 162 Malignant Thyroid Nodules that were Interpreted as Benign Based on Ultrasound Findings.

PURPOSE: The goal of this study was to estimate the risk of malignant thyroid nodules being interpreted as benign based on ultrasound findings and to clarify the pathological features of these malignant nodules. MATERIALS AND METHODS: We retrospectively re-evaluated ultrasound and pathological findings for 162 malignant thyroid nodules that were initially interpreted as benign based on ultrasound findings at Kuma Hospital between April 2012 and June 2015. RESULTS: The incidences of malignancy among "benign" thyroid nodules were 0.5% overall and 6.2% among resected nodules. In addition, 82.7% of thyroid nodules that were originally judged to have low or very low suspicion patterns were subsequently re-categorized as having high or intermediate suspicion patterns. The incidences of irregular margins (63.6%) and low echogenicity (36.4%) were higher than those of punctate microcalcification (17.9%) and the taller-than-wide shape (20.4%). Among microcarcinomas, the incidences were 65.7% for irregular margins and 51.4% for low echogenicity. Rim calcification with small extrusive soft tissue components and extrathyroidal extensions were not observed. After re-evaluation, 40.0% of papillary thyroid carcinomas remained benign based on their variants, such as the encapsulated, follicular, macrofollicular, and oxyphilic cell variants. CONCLUSION: We conclude that more careful observation, especially for lesions with irregular margins and low echogenicity, can help improve the diagnostic accuracy of thyroid ultrasonography. Furthermore, greater care may decrease the incidence of malignancy among thyroid nodules with low or very low suspicion patterns. Some variants of papillary thyroid carcinoma can have benign ultrasound findings.

Sonographic Evaluation of Nodules Newly Detected in the Neck After Thyroidectomy: Suture Granuloma Versus Recurrent Carcinoma.

PURPOSE: This study aimed to clarify the sonographic features of suture granuloma and recurrent carcinoma newly detected after thyroidectomy. MATERIALS AND METHODS: We retrospectively analyzed ultrasound reports with images of 25 cases of suture granuloma and 18 cases of recurrent carcinoma that newly appeared in the resected area after thyroidectomy in our institution. RESULTS: Both suture granulomas and recurrent carcinomas more frequently exhibited multiple lesions rather than solitary lesions. Suture granulomas tended to appear in the more superficial areas than the carotid artery, while recurrent carcinomas were more common between the trachea and carotid artery. A total of 10 of the 11 suture granulomas that we followed up decreased in size. Recurrent carcinomas showed irregular shape (55.6%), taller-than-wide shape (38.9%), low internal echogenicity (83.3%), and no punctate microcalcifications. By contrast, suture granulomas were fusiform in shape (56.0%) and showed linear internal echo parallel to the tissue plane on the longitudinal scan (64.0%). The vascular flow sign was mild to none in the majority of both lesions. CONCLUSION: Fusiform shape and linear internal echoes indicate suture granuloma, while irregular shape, taller-than-wide shape, and low echogenicity indicate recurrent carcinoma. Given that the clinical management of suture granuloma differs from that of recurrent carcinoma, it is important to distinguish between these two lesions.