Comparisons Between Normocalcemic Primary Hyperparathyroidism and Typical Primary Hyperparathyroidism.

BACKGROUND: Normocalcemic primary hyperparathyroidism (NPHPT) was first described in 2008. It is defined as consistently elevated serum parathyroid hormone (PTH) levels with normal serum calcium (sCa) concentration, after excluding secondary causes of PTH elevation. However, the exact definition and management strategy for NPHPT remain controversial. We retrospectively investigated the clinicopathological features and short-term outcomes of NPHPT patients. METHODS: A total of 280 patients who were surgically indicated for primary hyperparathyroidism (PHPT) at the Yonsei Severance Medical Center between 2015 and 2019 were included. Patients were classified according to preoperative PTH, corrected sCa, and ionized calcium (iCa) levels as follows: typical primary hyperparathyroidism (TPHPT, elevated PTH, sCa, and iCa, n = 158) and NPHPT (elevated PTH, normal sCa, n = 122). RESULTS: NPHPT was commonly seen in younger individuals (aged < 50 years, P = 0.025); nephrolithiasis and bone fractures were common. Preoperative PTH level was higher in the TPHPT group (P < 0.001). The NPHPT group had higher numbers of multiple parathyroid lesions (P = 0.004) that were smaller (P = 0.011). NPHPT patients were further divided into two subgroups according to iCa levels: the elevated (n = 95) and normal iCa (n = 27) groups. There was no significant difference between the two subgroups regarding symptoms and multiplicity of lesions. CONCLUSION: We found that NPHPT may be a heterogeneous disease entity of PHPT with high rates of multi-gland disease, which appears to be biochemically milder but symptomatic. Intraoperative PTH monitoring might help increase the surgery success rate. Moreover, the short-term outcomes of NPHPT after surgery did not differ from that of TPHPT.

Single-port transaxillary robotic thyroidectomy (START): 200-cases with two-step retraction method.

BACKGROUND: This study aims to report the results of a pioneering clinical study using the single-port transaxillary robotic thyroidectomy (START) for 200 patients with thyroid tumor and to introduce our novel two-step retraction method. METHODS: START was performed on consecutive 200 patients using the da Vinci Single-Port (SP) robot system from January 2019 to September 2020 at the Yonsei University Health System, Seoul, Korea. The novel two-step retraction technique, in which a 3.5 cm long incision is made along the natural skin crease, was used for the latter 164 patients. The surgical outcome and invasiveness of the SP two-step retraction method were analyzed. RESULTS: Among the 200 cases who underwent START, 198 were female and 2 were male, with a mean age of 34.7 (range: 13-58 years). Thyroid lobectomy was performed for 177 patients and total thyroidectomy was performed for 23 patients. Ten patients had benign thyroid nodules, whereas the other 190 had thyroid malignancy. The mean body mass index (BMI) was 22.2 ± 3.7 kg/m2 (range: 15.9-37.0 kg/m2). All of the operations were performed successfully without any open conversions, and patients were discharged on postoperative day 3 or 4 without significant complication. The mean operative time for thyroid lobectomy with the two-step retraction method was 116.69 ± 23.23 min, which was similar to that in the conventional robotic skin flap method (115.33 ± 17.29 min). We could minimize the extent of the robotic skin flap dissection with the two-step retraction method. CONCLUSIONS: START is a practical surgical method. By employing the new two-step retraction method, we can maximize the cosmetic and functional benefits for patients and reduce the workload fatigue of surgeons by increasing robotic dependency.

Feasibility and safety of the posterior retroperitoneoscopic approach in the resection of aortocaval and infrarenal paraganglioma: a single-center experience.

BACKGROUND: The posterior retroperitoneoscopic approach (PRA) has been under attention as a method for resection of paraganglioma (PGL) for the past few years. However, only a few studies have explored the effectiveness and safety of the PRA for aortocaval and infrarenal PGL resection. METHODS: We designed this retrospective study to investigate the safety and effectiveness of the PRA for aortocaval and infrarenal PGL resection in a single center. We retrospectively reviewed the medical records of patients who underwent PRA for PGL resection at our medical center from January 2006 to March 2021. Eight patients were enrolled, of whom six had aortocaval PGL. We investigated the surgical outcomes of enrolled patients. RESULTS: The locations of the tumors in relation to the renal vein were: suprarenal in two (25.0%) patients, at the renal vein level in three (37.5%) patients, and infrarenal in three (37.5%) patients. The mean operative time of the enrolled patients was 101.5 ± 39.1 min. The mean postoperative stay was 3.5 ± 1.5 days, and the estimated blood loss was 31.3 ± 51.4 ml. There was one minor complication (chyle leakage), and two hypotensive events occurred during the surgery. Focusing on the results of the renal vein level and infrarenal PGL resection, the mean operative time, mean postoperative stay, and estimated blood loss of the patients were 109.2 ± 41.3 min, 3.5 ± 1.8 days, and 41.7 ± 56.4 ml, respectively. CONCLUSION: The PRA for aortocaval and infrarenal PGL resection is feasible and safe. Additional data analysis and long-term follow-up are needed in the future.

Long-term outcomes of abdominal paraganglioma.

PURPOSE: Paragangliomas (PGL) are rare neuroendocrine tumors derived from chromaffin cells of the autonomic nervous system. We aim to describe our experience and the long-term outcome of abdominal PGL over the last decade. METHODS: A retrospective review of patients diagnosed with PGL in our hospital between November 2005 and June 2017 was conducted. All nonabdominal PGL were excluded and the clinicopathological features and long-term outcomes of the patients were analyzed. RESULTS: A total of 46 patients were diagnosed with abdominal PGL. The average age of diagnosis was 55.4 years and there was no sex predilection. The average tumor size was 5.85 cm and they were predominantly located in the infrarenal position (50%). The mean follow-up period was 42 months (range, 1.8-252 months). All patients with metastases had Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) of ≥4. One patient presented with synchronous metastases while 2 developed local recurrence and distant metastases. One presented with only local recurrence. One patient died 5 years after diagnosis. CONCLUSION: Abdominal PGL is a rare tumor with excellent long-term prognosis. Recurrence although uncommon, can occur decades after initial diagnosis. Long-term follow-up is therefore recommended for all patients with PGL, especially in patients with PASS of ≥4.

Benefit of diverse surgical approach on short-term outcomes of MEN1-related hyperparathyroidism.

Surgical excision is the preferred treatment for multiple endocrine neoplasia type 1 (MEN1)-related primary hyperparathyroidism (PHPT), although controversy regarding the surgical strategy exists. We retrospectively investigated the short-term outcomes of PHPT by various surgical extents. Thirty-three patients who underwent parathyroidectomy due to MEN1-related PHPT at Yonsei Severance Hospital between 2005 and 2018 were included (age [mean ± SD], 43.4 ± 14.1 [range, 23-81] years). Total parathyroidectomy with auto-transplantation to the forearm (TPX) was the most common surgical method (17/33), followed by less-than-subtotal parathyroidectomy (LPX; 12/33) and subtotal parathyroidectomy (SPX; 4/33). There was no postoperative persistent hyperparathyroidism. Recurrence was high in the LPX group without significance (1 in TPX, 2 in SPX, and 3 in LPX, p = 0.076). Permanent and transient hypoparathyroidism were more common in TPX (n = 6/17, 35.3%, p = 0.031; n = 4/17, 23.5%, p = 0.154, respectively). Parathyroid venous sampling (PVS) was introduced in 2013 for preoperative localisation of hyperparathyroidism at our hospital; nine among 19 patients operated on after 2013 underwent pre-parathyroidectomy PVS, with various surgical extents, and no permanent hypoparathyroidism (p = 0.033) or post-LPX recurrence was observed. Although TPX with auto-transplantation is the standard surgery for MEN1-related PHPT, surgical extent individualisation is necessary, given the postoperative hypoparathyroidism rate of TPX and feasibility of PVS.

Cystic Lateral Lymph Node Metastases From Papillary Thyroid Cancer Patients.

OBJECTIVES/HYPOTHESIS: Papillary thyroid carcinoma (PTC) tends to metastasize rather early to local lymph nodes (LNs). Incidences of cystic LN metastases is relatively rare compared with that of solid LN metastases. Few studies have attempted to assess the characteristics in these patients. This study aimed to compare the clinicopathologic characteristics and surgical outcomes between patients with cystic LN metastases and those with solid LN metastases. STUDY DESIGN: Retrospective cohort study. METHODS: We retrospectively reviewed the data of 1,028 patients with N1b PTC who underwent bilateral total thyroidectomy with central compartment neck dissection and modified radical neck dissection between January 2005 and September 2011. Of these, 136 (13.2%) had cystic LN metastases and 892 (86.8%) had solid LN metastases. Clinicopathologic characteristics and surgical outcomes were compared between these two patient groups. RESULTS: The proportion of patients with thyroid tumor multifocality was relatively higher in the cystic node cohort (19.9% vs. 12.7%, P = .048). The number of total metastatic LNs and positive lateral LNs was slightly higher in the cystic node cohort (11.3 ± 8.9 vs. 9.7 ± 7.5, P = .029 and 6.9 ± 6.3 vs. 5.5 ± 4.6, P = .018, respectively). The proportion of patients with recurrence was higher in the cystic node cohort (14.0% vs. 3.0%, P < .001). Multivariate analysis indicated that cystic nodes were a significant risk factor for recurrence (hazard ratio: 5.265, 95% confidence interval: 2.898-9.563). CONCLUSIONS: This study demonstrates that cystic lateral LN metastases are associated with aggressive tumor behavior in PTC patients. and that their presence is a significant independent prognostic factor for disease-free survival. LEVEL OF EVIDENCE: 2b Laryngoscope, 2020.

Peripheral location and infiltrative margin predict invasive features of papillary thyroid microcarcinoma.

OBJECTIVE: Tumor location in papillary thyroid microcarcinoma (PTMC) might determine tumor outgrowth from the thyroid gland. However, the clinical implications of tumor location and minimal extrathyroid extension (mETE) have not been well elucidated. We aimed to investigate the relationship between tumor location and mETE to predict the aggressiveness of PTMC. METHODS: A total of 858 patients with PTMC were grouped according to tumor location on ultrasonography: central (cPTMC) and peripheral PTMC (pPTMC). PTMC without mETE (PTMC-mETE(-)) was divided further according to margin shape: encapsulated (E-) or infiltrative (I-). To understand the molecular biologic characteristics of PTMC presenting with an I-margin and mETE, transcriptome data from TCGA-THCA were analyzed using Gene Set Enrichment Analysis (GSEA). RESULTS: pPTMC (n = 807, 94.1%) accounted for the majority of cases; mETE was identified only in pPTMC (403/807; 49.9%). pPTMC-mETE(+) showed aggressive clinical characteristics that increased the odds ratio (OR) for lymph node metastasis (LNM). Interestingly, subgroup analysis of PTMC-mETE(-) revealed that the I-margin also increased the OR for LNM, independent of other clinical factors. GSEA of TCGA-THCA data suggested coordinated upregulation of genes related to epithelial-mesenchymal transition (EMT) in PTC with mETE. Immunohistochemical staining for laminin subunit gamma 2 (LAMC2), CD59, E-cadherin and vimentin showed that these markers of EMT were associated with progressive changes in E-margin PTMC-mETE(-), I-margin PTMC-mETE(-) and pPTMC-mETE(+). CONCLUSION: mETE related to peripheral location of PTMC is an important predictor of tumor invasiveness, as is the I-margin, which presents with EMT features similar to mETE. I-margin PTMC-mETE(-) and pPTMC-mETE(+) might reflect the pattern of invasive PTMC.

Clinical correlation of a new practical MRI method for assessing cervical spinal canal compression.

OBJECTIVE: The purpose of this study was to evaluate interobserver agreement and whether or not a new MRI grading system correlates with symptoms and neurologic signs for assessing spinal canal compression. MATERIALS AND METHODS: One hundred patients (52 men and 48 women; mean age, 50 years) underwent MRI of the cervical spine at our institution and were evaluated by two musculoskeletal radiologists. The presence and grade of cervical canal stenosis at the maximal narrowing point was assessed according to the new grading system suggested by Kang et al. (Kang system). The results correlated with the clinical manifestations and neurologic examination. Statistical analysis was performed using kappa statistics, categoric regression analysis, and nonparametric correlation analysis (Spearman correlation). RESULTS: Interobserver agreement in the grading of spinal stenosis between the two readers was almost perfect (κ = 0.925). Most of the patients with grade 0 cervical canal stenosis showed no neurologic manifestation, and patients with grades 2 and 3 cervical canal stenosis had positive neurologic manifestations. The correlation coefficient (R) of reader 1 between MRI grade (0, 1, 2, and 3) and neurologic manifestations (positive or negative) was 0.846. The R of reader 2 was 0.808. In the younger age group (< 50 years old), the R of reader 1 was 0.834 and the R of reader 2 was 0.745. In the older age group (≥ 50 years old), the R of reader 1 was 0.839 and the R of reader 2 was 0.839. CONCLUSION: The interobserver agreement of the Kang system was almost perfect and was higher than in the study by Kang et al. Grade 0 cervical canal stenosis represents negative neurologic manifestations and grades 2 and 3 cervical canal stenosis represent positive neurologic manifestations. The Kang system and clinical manifestations are significantly correlated, especially in the older age group (≥ 50 years).