Yun-Sung Lim

Lateral cervical lymph node metastases from papillary thyroid carcinoma: predictive factors of nodal metastasis.

BACKGROUND Papillary thyroid carcinoma (PTC) frequently metastasizes to the regional neck; skip metastasis (metastasis to the lateral compartment in the absence of central disease) is uncommon. This prospective study was to evaluate the incidence of occult lateral neck metastasis (LNM) and elucidated the factors that predict LNM in PTC with central neck metastasis (CNM) by performing prophylactic selective lateral neck dissection (SND). METHODS Sixty-two patients with PTC without clinical LNM underwent total thyroidectomy with central compartment neck dissection and prophylactic SND consecutively after ipsilateral CNM was confirmed by intraoperative frozen biopsy. RESULTS The incidence of occult LNM in PTC was 55%. Patients with LNM had a larger primary tumor and more positive ipsilateral and bilateral central lymph nodes than patients without LNM. There were no differences between patients with and without LNM with regard to age and extrathyroidal extension. The incidence of occult LNM increased significantly as the number of metastatic ipsilateral and bilateral lymph nodes increased. Independent risk factors for occult LNM were tumor size and the number of positive bilateral lymph nodes (odds ratio [OR] = 1.449; OR = 1.110, respectively). The most common metastatic site was level III (68%: 23/34), followed by level IV (59%: 20/34) and level II (21%: 7/34). CONCLUSION The important risk factors for LNM in PTC are primary tumor size and the number of positive bilateral central lymph nodes. Prophylactic SND may be considered in selected patients with a large number of positive central lymph nodes and large tumors.

Tumor location–dependent skip lateral cervical lymph node metastasis in papillary thyroid cancer

Lateral cervical lymph node metastasis without central lymph node (CLN) metastasis is not infrequent in papillary thyroid cancer (PTC). This study was designed to investigate the frequency and pattern of skip metastasis in PTC.

Nodal status of central lymph nodes as a negative prognostic factor for papillary thyroid carcinoma

The status of metastatic lymph nodes, including the size and extracapsular spread (ECS), in papillary thyroid cancer (PTC) has not been well established. This study evaluated the correlation between the specific status of central lymph node metastases (CLNM) and negative prognostic factors.

Frozen biopsy of central compartment in papillary thyroid cancer: Quantitative nodal analysis

Nodal metastasis in papillary thyroid cancer (PTC) usually occurs in the central compartment of the ipsilateral neck and spreads laterally. The purpose of this study was to evaluate the diagnostic accuracy of frozen biopsy for quantitative nodal evaluation of central neck metastasis in PTC.

Isolation of Mesenchymal Stromal Cells (MSCs) from Human Adenoid Tissue

Background: Mesenchymal stromal cells (MSCs) are multipotent progenitor cells that originally derived from bone marrow. Clinical use of bone marrow-derived MSC is difficult due to morbidity and low MSC abundance and isolation efficiency. Recently, MSCs have been isolated from various adult tissues. Here we report the isolation of adenoid tissue-derived MSCs (A-MSCs) and their characteristics. Methods: We compared the surface markers, morphologies, and differentiation and proliferation capacities of previously established tonsil-derived MSCs (T-MSCs) and bone marrow-derived MSCs (BM-MSCs) with cells isolated from adenoid tissue. The immunophenotype of A-MSCs was investigated upon interferon (IFN)-γ stimulation. Results: A-MSCs, T-MSCs, and BM-MSCs showed negative CD45, CD31 HLA-DR, CD34, CD14, CD19 and positive CD 90, CD44, CD73, CD105 expression. A-MSCs were fibroblast-like, spindle-shaped non-adherent cells, similar to T-MSCs and BM-MSCs. Adipogenesis was observed in A-MSCs by the formation of lipid droplets after Oil Red O staining. Osteogenesis was observed by the formation of the matrix mineralization in Alizarin Red staining. Chondrogenesis was observed by the accumulation of sulfated glycosaminoglycan-rich matrix in collagen type II staining. These data were similar to those of T-MSCs and BM-MSCs. Expression of marker genes (i.e., adipogenesis; lipoprotein lipase, proliferator-activator receptor-gamma, osteogenesis; osteocalcin, alkaline phasphatase, chondrogenesis; aggrecan, collagen type II α1) in A-MSCs were not different from those in T-MSCs and BM-MSCs. Conclusions: A-MSCs possess the characteristics of MSCs in terms of morphology, multipotent differentiation capacity, cell surface markers, and immunogeneity. Therefore, A-MSCs fulfill the definition of MSCs and represent an alternate source of MSCs.

Ultrasonographic findings relating to lymph node metastasis in single micropapillary thyroid cancer

BackgroundIn thyroid cancer, preoperative ultrasonography (US) is performed to detect the primary tumor and lymph node metastasis (LNM), which are related to prognosis. This study examined the relationships between specific US findings and LNM in micropapillary thyroid cancer (MPTC).MethodsData on 220 patients with solitary MPTC who underwent total thyroidectomy and neck dissection between 2008 and 2009 were evaluated retrospectively. We classified the US findings according to the nature, shape, echogenicity, extent, margin, and calcification of the primary tumor and evaluated the correlations between these findings and those of LNM.ResultsHypoechogenicity (odds ratio = 2.331, P = 0.025) and marked hypoechogenicity (OR = 4.032, P = 0.016) of MPTC were risk factors for central LNM. All of the patients with lateral cervical LNM showed hypoechogenicity or marked hypoechogenicity. Hypoechogenicity (odds ratio = 5.349, P = 0.047) and other types of calcification (odds ratio = 2.495, P = 0.010) were significant risk factors for lateral cervical LNM.ConclusionsSpecific sonographic findings (hypoechogenicity or marked hypoechogenicity, and calcification) suggest LNM.

Intracordal auricular cartilage injection for unilateral vocal fold paralysis

We evaluated the efficacy and outcome of intracordal auricular cartilage injection in patients with unilateral vocal fold paralysis. Our interest developed from findings of a canine model study that reported that histologic characteristics of cartilage were preserved 2 and 3 years after intracordal autologous cartilage injection. Between May 2002 and July 2010, 29 patients with breathy dysphonia caused by unilateral vocal fold paralysis underwent intracordal auricular cartilage injection. Each subject underwent preoperative and postoperative perceptual assessments, acoustical voice analysis, and videostroboscopy. Fourteen patients were male, and the mean age was 52-years old. Patients were tracked for a mean duration of 257 days. Injections were performed through a transoral approach under general anesthesia. Perceptual assessments by GRBAS scale, acoustic parameters of jitter, shimmer, noise-to-harmonic ratio, and maximum phonation time significantly improved at 3, 6, and 12 months after cartilage injection (p < 0.005). No major complications were observed after injection. Initial clinical results with intracordal auricular cartilage injection are promising for patients with unilateral vocal fold paralysis. Autologous auricular cartilage can be a safe, effective, and alternative material for vocal fold medialization, and can be a long lasting one.

New Technique for Preparing Cartilage for Intracordal Injection: The Freezing and Grinding Method

OBJECTIVES/HYPOTHESIS We developed a technique for preparing harvested cartilage that creates finer, more uniform pieces by freezing with liquid nitrogen and grinding with a mortar and pestle. Herein, we report the application of this new technique for intracordal cartilage injection. STUDY DESIGN Experimental study. METHODS Human cartilage was obtained from surgical cases. In the standard method, harvested cartilage was prepared with scissors and a knife. In the experimental group, harvested cartilage was frozen with liquid nitrogen and ground with a mortar and pestle. RESULTS It took an average of 60 minutes to manipulate cartilage using the standard technique, whereas it took an average of 10 minutes using the freezing and grinding method (P<0.001). The average size of cartilage flakes generated by the standard and new techniques were 727 and 48.6 μm, respectively. The cartilage flakes produced using scissors and a knife were able to pass through a 19-gauge needle, whereas those created using the freezing and grinding method were able to pass through a 24-gauge needle. CONCLUSIONS Using the freezing and grinding method, cartilage was broken into fine, uniform pieces that could pass through a 24-gauge needle. This new technique will facilitate the production of commercial cartilage material for intracordal injection.

Development of 2D Scanning Videokymography

Objectives: Videolaryngostroboscopy, electroglottography, and high-speed video systems are now in use to evaluate vocal cord vibration, which is crucial for voice production. The limitations of videolaryngostroboscopy are 1) the images captured from stroboscopy are not a real vocal cord vibration, and 2) it is difficult to identify each vocal cord mucosal wave in aperiodic dysphonia. The line scanning videokymography was developed to overcome the limitations of stroboscopy, but it only selects one active horizontal line from the whole laryngeal image. The aims of this study are to evaluate the whole laryngeal mucosal wave simultaneously in real time, to overcome the distortions caused by patient movements, to quantify parameters from images using software, and to compare both vocal cord movements and mucosal wave. Methods: We developed 2D scanning videokymography using high brightness continuous light source, full HD camera, capture board, and analyzing software. The system makes it possible to observe fundamental frequency, amplitude, regularity, mucosal wave, phase difference, etc. Results: We can analyze whole vocal cord movement in real-time and mucosal wave in any area. We can objectively measure specific parameters of vocal cord vibration. Conclusions: 2D scanning videokymography is a very effective diagnostic tool for aperiodic vocal cord vibration case. It does not require post-processing procedure. 2D scanning videokymography can prevent distortion of images from patient motion resulting from line scanning videokymography.

Relationship between Ultrasonographic Echogenecity and Intratumoral Fibrosis and Growth Pattern in Papillary Thyroid Carcinoma

Objectives: Ultrasonography (USG) is a powerful tool for evaluation of papillary thyroid cancer (PTC). Preoperative USG characteristics correlated with several prognostic factors for PTC. Tumor fibrosis is known to be an important histologic prognostic features in head and neck cancer. However, there is a lack of studies for tumor fibrosis in PTC. This study aimed to evaluate the relationship between ultrasonographic finding and intratumoral fibrosis and growth pattern in PTC. Methods: In all, 170 fresh cases with PTC patients underwent total thyroidectomy with central neck dissection (CND). Lateral neck dissection was performed in case of lateral neck metastasis. Retrospective analysis for USG finding such as echogenicity and pathologic characteristics including intratumoral fibrosis and tumor growth pattern were conducted. Results: Ninety (53%) patients had USG finding with marked hypoechogenecity. According to histologic characteristics, group with marked hypoechogenecity had more tumor fibrosis and more invasive growth pattern than the group with iso- or hypoechogenecity. There was no significant difference in age, sex, tumor size, extrathyroidal extension, and presence of central or lateral neck metastasis between the two groups. In univariate and multiple regression analysis, tumor fibrosis and growth pattern were significantly associated with USG echogenecity. Conclusions: These findings suggest that intratumoral fibrosis and tumor growth pattern are important determinants of preoperative ultrasonographic echogenecity in PTC.