The Diagnostic Role of Repeated Biopsy of Thyroid Nodules with Atypia of Undetermined Significance with Architectural Atypia on Core-Needle Biopsy

Background@#We aimed to evaluate the utility of repeat biopsy of thyroid nodules classified as atypia of undetermined significance with architectural atypia (IIIB) on core-needle biopsy (CNB). @*Methods@#This retrospective study evaluated patients with thyroid nodules categorized as IIIB on CNB between 2013 and 2015. Demographic characteristics, subsequent biopsy results, and ultrasound (US) images were evaluated. The malignancy rates of nodules according to number of CNBs and the number of IIIB diagnoses was compared. Demographic and US features were evaluated to determine factors predictive of malignancy. @*Results@#Of 1,003 IIIB nodules on CNB, the final diagnosis was determined for 328 (32.7%) nodules, with 121 of them confirmed as malignant, resulting in a malignancy rate of 36.9% (95% confidence interval, 31.7% to 42.1%). Repeat CNB was performed in 248 nodules (24.7%), with 75 (30.2%), 131 (52.8%), 13 (5.2%), 26 (10.5%), one (0.4%), and two (0.8%) reclassified into categories II, IIIB, IIIA, IV, V, and VI, respectively. Malignancy rates were not significantly affected by the number of CNBs (P=0.291) or the number of IIIB diagnoses (P=0.473). None of the nodules confirmed as category II on repeat CNB was malignant. US features significantly associated with malignancy (P<0.003) included solid composition, irregular margins, microcalcifications, and high suspicion on the US risk stratification system. @*Conclusion@#Repeat biopsy of nodules diagnosed with IIIB on CNB did not increase the detection of malignancy but can potentially reduce unnecessary surgery. Repeat biopsy should be performed selectively, with US features guiding the choice between repeat biopsy and diagnostic surgery.

Pompholyx and Eczematous Reaction After Intravenous Immunoglobulin Therapy for Patient with Guillain-Barré Syndrome / 대한피부과학회지

Cutaneous adverse events associated with intravenous immunoglobulin (IVIG) have a relatively low significance, ranging from 0.4% to 6%. In Korean dermatology literature, eczematous reactions associated with the use of IVIG have been underestimated. A 34-year-old male presented with a 2-week history of multiple vesicles on both hands and diffuse eczematous lesions on the trunk and both arms. He had been diagnosed with Guillain-Barré syndrome and had received IVIG at a dosage of 0.4 g/kg/d for 5 days during hospitalization. One week after discharge, cutaneous manifestations developed, starting with tiny blisters on both hands and progressing to eczematous patches on the trunk and arms.Histopathologic examination revealed spongiotic dermatitis with intracorneal bullae formation. A diagnosis of palmar pompholyx and systemic eczematous reaction associated with the administration of IVIG was made. Treatment with systemic corticosteroid, antihistamines and topical steroid was initiated. At a 2-week follow-up, significant improvement was observed.

Insulin-Derived Cutaneous Amyloidosis: A Possible Complication of Repeated Insulin Injections

Primary localized cutaneous amyloidosis (PLCA) is characterized by extracellular deposition of pathological fibril aggregation of proteins in the skin without systemic involvement.Macular amyloidosis, lichen (papular) amyloidosis, and nodular amyloidosis are three different subtypes of PLCA. Although the pathological mechanism of PLCA has not yet been clarified, it is assumed that a nucleus formation of amyloid fibril is formed due to repeated external stimulation, such as subcutaneous injection, which often poses diagnostic challenges. Herein, we present a 54-year-old Korean male patient with cutaneous localized amyloidosis which occurred after repeated local insulin injections, and discuss the relationship between insulin therapy in patients with diabetes mellitus and dermal amyloid deposition.

Fixed Drug Eruption in a Patient Taking Valacyclovir without Cross-Reactivity to Acyclovir

Fixed drug eruption (FDE) is a well-defined hyperpigmented patch that recurs in a fixed location each time a particular drug is taken. Common causative agents of FDE are nonsteroidal anti-inflammatory drugs, non-narcotic analgesics, sedatives, anticonvulsants, sulfonamides, and tetracycline. We report a 33-year-old male who presented with a recurrent, localized, brownish-to-erythematous macule and papules on the peri-philtrum area two hours after taking valacyclovir. Three episodes of valacyclovir ingestion for treatment of Herpes simplex virus infection provoked a similar skin rash at the same site. Histopathology results showed vacuolar degeneration in the basal layer of the epidermis, pigmentary incontinence, and perivascular inflammatory cell infiltration in the papillary dermis. Although patch test and skin prick test showed negative responses to acyclovir and valacyclovir, an intradermal test showed a positive reaction only to valacyclovir. The oral provocation test to acyclovir and valacyclovir showed a positive reaction only to valacyclovir. Through drug history, histopathological examination, patch test, intradermal test, and oral provocation test, we established a final diagnosis of FDE due to valacyclovir without cross-reactivity to acyclovir. To find alternative therapeutic drugs, we suggest diagnostic tests with not only the suspected drugs, but also other drugs in the same class.

Treatment Outcomes of Oral Acitretin versus Alitretinoin for Psoriasis:A Retrospective Review of 65 Cases / 대한피부과학회지

Background@#Oral acitretin (ACT) has been approved for the treatment of psoriasis (PSO), whereas alitretinoin (ALI) has been prescribed off-label. Few studies have compared the efficacy of these two therapeutics. @*Objective@#To evaluate the clinical outcomes of oral ACT versus ALI for treating PSO. @*Methods@#Sixty-five patients diagnosed with PSO and treated with ACT or ALI were reviewed. Patient demographics, clinical efficacy, and adverse effects were evaluated. Treatment efficacy was assessed using physician’s global assessment (PGA) and psoriasis area and severity index (PASI). @*Results@#A total of 38 cases in the ACT group and 27 cases in the ALI group in PSO were retrospectively reviewed. No significant intergroup differences were noted in the proportion of patients achieving PGA score of “clear” or “almost clear” (18.42% vs. 22.22%; p=0.71). The reduction rate of PASI from baseline was higher in the ALI group (24.30% vs. 22.74%; p=0.68), while the rate of achieving 75% improvement in PASI was higher in the ACT group (18.42% vs. 14.81%; p=0.75); no significantly differences were noted. The ALI group had fewer adverse effects (6/27 [22.22%]) than the ACT group (10/38 [26.32%]), and no severe events occurred in either group. @*Conclusion@#ALI can be considered an off-label treatment option for a limited patient population.

An Excimer Laser-Induced Eruptive Sebaceous Hyperplasia

Sebaceous hyperplasia (SH) is a benign proliferation of the sebaceous glands. Ultraviolet radiation is known to be the cofactor for the pathogenesis of SH. Frequently reported adverse events of 308-nm excimer laser are erythema, burning or pain, and itching sensation.However, the role of excimer laser as an aetiological factor of SH is rarely reported in the literature. A 59-year-old female presented with several elevated, umbilicated papules on the face. Papular eruption appeared abruptly after 11 weeks of treatment for vitiligo which includes 308-nm excimer laser therapy. The distribution of lesion was associated with the treated area. Total cumulative dose was 3,300 mJ/cm 2 over 16 sessions. Histopathologic findings showed enlarged sebaceous glands composed of numerous lobules around a centrally located, widened sebaceous duct. Chronic sun exposure clinically causes SH was proved in the previous animal studies. Thus, we introduce a rare case of eruptive SH in the patient treated with 308-nm excimer laser.

Pathologically Confirmed Subcutaneous Fat and Lymphovascular Invasion of a Hypopigmented Area in Extramammary Paget Disease

Extramammary Paget disease (EMPD) is a rare adenocarcinoma that usually occurs in areas of the body that are rich in apocrine sweat glands. Great depth of tumor invasion is a well-known risk factor for worse prognosis. Paget cells usually are limited to the epidermis, whereas invasive EMPD, which infiltrates the dermis, is relatively rare. It is even rarer for the tumor to spread beyond the dermis. Only 3.1% of patients with EMPD of the penis and scrotum have exhibited infiltration of the subcutaneous fat layer. We report a case of a 62-year-old male with EMPD that invaded the subcutaneous fat layer. He presented with a several-year history of a slowly expanding erythematous plaque with the hypopigmented area on the left penoscrotum. One month before presentation, the patient had undergone punch biopsy at another hospital and diagnosed with EMPD. He had no personal history of urogenital cancers. The patient was treated with Mohs micrographic surgery, and negative margins were achieved after four stages. The histopathologic findings revealed Paget cells scattered throughout the epidermis. At the hypopigmented area, Paget cells extended to the subcutaneous fat layer with lymphovascular invasion. There was no evidence of recurrence at seven months postoperatively. Herein, we describe a case of hypopigmented EMPD that infiltrated the subcutaneous layer, which rarely has been reported in Korea.

Impact of Additional Preoperative Computed Tomography Imaging on Staging, Surgery, and Postsurgical Survival in Patients With Papillary Thyroid Carcinoma

Objective@#We investigated the impacts of computed tomography (CT) added to ultrasound (US) for preoperative evaluation of patients with papillary thyroid carcinoma (PTC) on staging, surgical extent, and postsurgical survival. @*Materials and Methods@#Consecutive patients who underwent surgery for PTC between January 2015 and December 2015 were retrospectively identified. Of them, 584 had undergone preoperative additional thyroid CT imaging (CT + US group), and 859 had not (US group). Inverse probability of treatment weighting (IPTW) and propensity score matching (PSM) were used to adjust for 14 variables and balance the two groups. Changes in nodal staging and surgical extent caused by CT were recorded.The recurrence-free survival and distant metastasis-free survival after surgery were compared between the two groups. @*Results@#In the CT + US group, discordant nodal staging results between CT and US were observed in 94 of 584 patients (16.1%). Of them, CT accurately diagnosed nodal staging in 54 patients (57.4%), while the US provided incorrect nodal staging. Ten patients (1.7%) had a change in the extent of surgery based on CT findings. Postsurgical recurrence developed in 3.6% (31 of 859) of the CT + US group and 2.9% (17 of 584) of the US group during the median follow-up of 59 months. After adjustment using IPTW (580 vs. 861 patients), the CT + US group showed significantly higher recurrence-free survival rates than the US group (hazard ratio [HR], 0.52 [95% confidence interval {CI}, 0.29–0.96]; P = 0.037). PSM analysis (535 patients in each group) showed similar HR without statistical significance (HR, 0.60 [95% CI, 0.31–1.17]; P = 0.134). For distant metastasis-free survival, HRs after IPTW and PSM were 0.75 (95% CI, 0.17–3.36; P = 0.71) and 0.87 (95% CI, 0.20–3.80; P = 0.851), respectively. @*Conclusion@#The addition of CT imaging for preoperative evaluation changed nodal staging and surgical extent and might improve recurrence-free survival in patients with PTC.

Diagnosis of parathyroid incidentaloma detected on thyroid ultrasonography: the role of fine-needle aspiration cytology and washout parathyroid hormone measurements

Purpose@#The aim of this study was to assess the diagnostic role of fine-needle aspiration cytology (FNAC) and analyze factors associated with false-negative FNAC results in patients with parathyroid incidentaloma who were referred for ultrasonography (US)-guided fine-needle aspiration (FNA) of thyroid nodules. @*Methods@#In this study, 121 patients with suspected parathyroid lesions were enrolled. The patients underwent US-guided FNAC with measurements of washout parathyroid hormone (PTH) between January 2015 and May 2020. The diagnostic performance of FNAC for the diagnosis of parathyroid lesions was assessed using surgical results and elevated washout PTH as a reference standard. The clinical and radiologic features associated with false-negative results on FNAC for the diagnosis of parathyroid lesions were evaluated. @*Results@#Among the 121 nodules assessed, 38 were parathyroid lesions (31.4%), and 83 were non-parathyroid lesions (68.6%). The diagnostic performance of FNAC for parathyroid incidentaloma showed a sensitivity of 31.6% (12/38), specificity of 100% (83/83), positive predictive values of 100% (12/12), negative predictive values of 76.1% (83/109), and accuracy of 78.5% (95/121). The FNAC results of non-parathyroid lesions included thyroid nodules, lymph nodes, neurogenic tumors, and fat tissue. True-positive results on FNAC were significantly associated with performing FNA twice (58.3% vs. 23.1%, P=0.043). @*Conclusion@#Considering the low sensitivity of FNAC, measuring washout PTH in addition to FNAC may help accurately diagnose parathyroid incidentaloma on thyroid US. Further, the falsenegative rate for FNAC can be reduced by obtaining two or more FNA samples.

Bullous Pilomatricoma Arising at a BNT162b2 mRNA COVID-19 Vaccination Site / 대한피부과학회지

Pilomatricoma is a common benign tumor that originates from hair matrix cells. Bullous pilomatricoma (BP) is a rare variant that often occurs on the upper extremities. A 23-year-old male presented with a cyst on the left upper arm for 6 months. He received the BNT162b2 (Pfizer) mRNA COVID-19 vaccine in the same location approximately 6 months prior to presentation. The lesion appeared 1 week after inoculation and gradually enlarged.Physical examination revealed a 2.5-×2.0-cm-sized, pinkish cystic nodule on the left upper arm. The lesion was excised, and histopathological examination showed a well-circumscribed nodule composed of basophilic cells and eosinophilic shadow cells. Finally, the patient was diagnosed with BP. The exact cause of BP formation following vaccination is yet to be determined; however, this report presents the possibility of BP occurrence in individuals with chronic skin lesions at the site of vaccination.

Epithelioid Blue Nevus with No Evidence of Carney Complex / 대한피부과학회지

Epithelioid blue nevus (EBN) is a rare variant of blue nevus characterized by large polygonal pigmented melanocytes. As EBN was first described in patients with Carney complex, familial lentiginosis, and low-grade multi-organ neoplasia syndrome, sporadic cases without such clinical features have been reported and debated as having considerable histopathological overlap with animal-type melanoma. A 34-year-old male presented with a well-defined, 2.0-×1.8-cm-sized, dome-shaped, grayish mass on the anterior aspect of the left ankle. A complete surgical resection of the lesion was performed. Histopathological findings revealed a well-circumscribed round tumor in the reticular dermis. Heavily pigmented epithelioid melanocytes were admixed with the collagen bundles. The lesion was diagnosed as EBN. A follow-up period of 9 months showed no evidence of recurrence or metastasis.Here, we report a sporadic case of EBN, which is rare in the Korean population.

Validation of CT-Based Risk Stratification System for Lymph Node Metastasis in Patients With Thyroid Cancer

Objective@#To evaluate the computed tomography (CT) features for diagnosing metastatic cervical lymph nodes (LNs) in patients with differentiated thyroid cancer (DTC) and validate the CT-based risk stratification system suggested by the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) guidelines. @*Materials and Methods@#A total of 463 LNs from 399 patients with DTC who underwent preoperative CT staging and ultrasound-guided fine-needle aspiration were included. The following CT features for each LN were evaluated: absence of hilum, cystic changes, calcification, strong enhancement, and heterogeneous enhancement. Multivariable logistic regression analysis was performed to identify independent CT features associated with metastatic LNs, and their diagnostic performances were evaluated. LNs were classified into probably benign, indeterminate, and suspicious categories according to the K-TIRADS and the modified LN classification proposed in our study. The diagnostic performance of both classification systems was compared using the exact McNemar and Kosinski tests. @*Results@#The absence of hilum (odds ratio [OR], 4.859; 95% confidence interval [CI], 1.593–14.823; P = 0.005), strong enhancement (OR, 28.755; 95% CI, 12.719–65.007; P < 0.001), and cystic changes (OR, 46.157; 95% CI, 5.07–420.234; P = 0.001) were independently associated with metastatic LNs. All LNs showing calcification were diagnosed as metastases. Heterogeneous enhancement did not show a significant independent association with metastatic LNs. Strong enhancement, calcification, and cystic changes showed moderate to high specificity (70.1%–100%) and positive predictive value (PPV) (91.8%–100%). The absence of the hilum showed high sensitivity (97.8%) but low specificity (34.0%). The modified LN classification, which excluded heterogeneous enhancement from the K-TIRADS, demonstrated higher specificity (70.1% vs. 62.9%, P = 0.016) and PPV (92.5% vs. 90.9%, P = 0.011) than the K-TIRADS. @*Conclusion@#Excluding heterogeneous enhancement as a suspicious feature resulted in a higher specificity and PPV for diagnosing metastatic LNs than the K-TIRADS. Our research results may provide a basis for revising the LN classification in future guidelines.

Immunoglobulin G4-Related Thyroid Disease: A Single-Center Experience and Literature Review

Background@#Immunoglobulin G4 (IgG4)-related disease is an entity that can involve the thyroid gland. The spectrum of IgG4-related thyroid disease (IgG4-RTD) includes Hashimoto thyroiditis (HT) and its fibrotic variant, Riedel thyroiditis, as well as Graves’ disease. The early diagnosis of IgG4-RTD is important because it is a medically treatable disease, and a delay in the diagnosis might result in unnecessary surgery. We present a case series of IgG4-RTD with a review of the literature. @*Methods@#We retrospectively reviewed the clinical presentation and the radiological and pathological findings of patients diagnosed with IgG4-RTD between 2017 and 2021 at a tertiary medical center in Korea. We also conducted a literature review of IgG4-RTD. @*Results@#Five patients were diagnosed with IgG4-RTD during the study period. The patients’ age ranged from 31 to 76 years, and three patients were men. Most patients visited the clinic for a neck mass, and hypoechogenic nodular lesions were observed on neck ultrasonography. Three patients had IgG4 HT, and two patients had IgG4 Riedel thyroiditis. All patients developed hypothyroidism that necessitated L-thyroxine replacement. The diagnosis of IgG4-RTD was confirmed after a pathological examination of the surgical specimen in the first two cases. However, the early diagnosis was possible after a core needle biopsy in three clinically suspected patients. @*Conclusion@#The diagnosis of IgG4-RTD requires clinical suspicion combined with serology and histological analyses using IgG4 immunostaining. The early diagnosis of IgG4-RTD is difficult; thus, biopsy with IgG4 immunostaining and serum IgG4 measurements will help diagnose patients suspected of having IgG4-RTD.

Radiofrequency ablation of recurrent thyroid cancers: anatomy-based management

Although differentiated thyroid cancer has an excellent prognosis and low mortality, its recurrence rate has been reported to be very high. While surgery is recommended as the standard treatment for recurrent thyroid cancer, reoperation may increase the incidence of complications due to fibrosis and anatomical distortion. In patients with high surgical risk or those who refuse repeated surgery, ultrasonography-guided ablation techniques including radiofrequency ablation, ethanol ablation, and laser ablation are suggested as alternative treatments. In this manuscript, we introduce an anatomy-based management concept for radiofrequency ablation for recurrent thyroid cancer, and present a review of the relevant literature, including indications, basic techniques, clinical outcomes, and complications.

Muscle Metastasis of Clear Cell Renal Cell Carcinoma Representing as Forearm Mass:A Case Report / 대한피부과학회지

Cutaneous metastases from renal cell carcinoma (RCC) present as rapidly growing erythematous or purple-round nodules. An 88-year-old male presented with a solitary, deep-seated firm mass on his left forearm that had persisted for 3 years. Ultrasonography revealed an hypervascular mass with rich vessels. Magnetic resonance imaging revealed a 1.6×1.6×3.3 cm sized, high T2-weighted signal intensity mass at brachioradialis muscle. Histopathologic examination revealed cells with atypical, pleomorphic, oval to spindle-shaped nuclei, and clear cytoplasm with an alveolar pattern within an unencapsulated, lobulated mass. Immunohistochemical analysis showed that the tumor cells were positive for PAX8, CD10, epithelial membrane antigen, and vimentin. Ultrasonography of the urinary tract revealed a lesion suspected to be RCC, which was thought to be the primary tumor. As our patient showed peculiar clinical symptoms and the primary tumor was later diagnosed as a metastatic lesion inversely, we report a rare case of metastatic RCC with an intramuscular mass on the forearm.

Pre-contoured reconstruction plate fabricated via three-dimensional printed bending support

A mandibular continuity defect can be repaired using either a prosthetic device or autogenous bone. A titanium reconstruction plate can be used with a localized or vascularized flap over the defect of the mandible. Unfortunately, the plate may fail due to plate exposure, screw loosening, fracture, or infection, and will need to be removed. Plate exposure though the skin or mucosa is one of the main reasons for failure. In the present work, the authors introduced a lingually positioned reconstruction plate fabricated via three-dimensional printed bending support. This custom reconstruction plate can avoid plate re-exposure as well as reduce surgical errors and operation time.

A Retrospective Analysis of the Factors Affecting the Treatment Outcomes of Cyclosporine in Patients with Psoriasis / 대한피부과학회지

Background@#Cyclosporine is an effective drug for the treatment of psoriasis. Nonetheless, little is known about the factors associated with its effectiveness. @*Objective@#This study aimed to analyze the factors affecting the treatment efficacy of cyclosporine in patients with psoriasis. @*Methods@#‘Good treatment response’ and ‘treatment failure’ were each defined as achievement of 75% improvement in the psoriasis area and severity index and failure to achieve 50% improvement in the psoriasis area and severity index, respectively. The factors affecting good treatment response were investigated by comparing the group that achieved psoriasis area and severity index 75 to the not achieved group. Similarly, we also analyzed the factors affecting treatment failure and the time required to achieve psoriasis area and severity index 75. @*Results@#In total, 78 patients (63 males and 15 females) were analyzed. Age of onset, body surface area, accompanying hypertension, accompanying psoriatic arthritis, induction phase mean dose, and cumulative dose showed a relationship with good treatment response. Body surface area, initial dose, and accompanying hypertension were correlated with treatment failure. The mean time taken to achieve psoriasis area and severity index 75 was 6.70±3.17 weeks and it did not correlate with any factor. @*Conclusion@#In patients with psoriasis vulgaris, maintaining an adequate mean dose in the induction phase may be necessary for successful treatment with cyclosporine, especially in the patients with early-onset psoriasis, severe psoriasis, or accompanying psoriatic arthritis. In addition, a sufficiently high start dose may be needed to prevent treatment failure, particularly in patients with severe psoriasis vulgaris.

MRI Predictors of Malignant Transformation in Patients with Inverted Papilloma: A Decision Tree Analysis Using Conventional Imaging Features and Histogram Analysis of Apparent Diffusion Coefficients

Objective@#Preoperative differentiation between inverted papilloma (IP) and its malignant transformation to squamous cell carcinoma (IP-SCC) is critical for patient management. We aimed to determine the diagnostic accuracy of conventional imaging features and histogram parameters obtained from whole tumor apparent diffusion coefficient (ADC) values to predict IP-SCC in patients with IP, using decision tree analysis. @*Materials and Methods@#In this retrospective study, we analyzed data generated from the records of 180 consecutive patients with histopathologically diagnosed IP or IP-SCC who underwent head and neck magnetic resonance imaging, including diffusion-weighted imaging and 62 patients were included in the study. To obtain whole tumor ADC values, the region of interest was placed to cover the entire volume of the tumor. Classification and regression tree analyses were performed to determine the most significant predictors of IP-SCC among multiple covariates. The final tree was selected by cross-validation pruning based on minimal error. @*Results@#Of 62 patients with IP, 21 (34%) had IP-SCC. The decision tree analysis revealed that the loss of convoluted cerebriform pattern and the 20th percentile cutoff of ADC were the most significant predictors of IP-SCC. With these decision trees, the sensitivity, specificity, accuracy, and C-statistics were 86% (18 out of 21; 95% confidence interval [CI], 65–95%), 100% (41 out of 41; 95% CI, 91–100%), 95% (59 out of 61; 95% CI, 87–98%), and 0.966 (95% CI, 0.912–1.000), respectively. @*Conclusion@#Decision tree analysis using conventional imaging features and histogram analysis of whole volume ADC could predict IP-SCC in patients with IP with high diagnostic accuracy.

Diagnostic Performance of the Modified Korean Thyroid Imaging Reporting and Data System for Thyroid Malignancy: A Multicenter Validation Study

Objective@#To evaluate the diagnostic performance of the modified Korean Thyroid Imaging Reporting and Data System (K-TIRADS), and compare it with the 2016 version of K-TIRADS using the Thyroid Imaging Network of Korea. @*Materials and Methods@#Between June and September 2015, 5708 thyroid nodules (≥ 1.0 cm) from 5081 consecutive patients who had undergone thyroid ultrasonography at 26 institutions were retrospectively evaluated. We used a biopsy size threshold of 2 cm for K-TIRADS 3 and 1 cm for K-TIRADS 4 (modified K-TIRADS 1) or 1.5 cm for K-TIRADS 4 (modified K-TIRADS 3). The modified K-TIRADS 2 subcategorized the K-TIRADS 4 into 4A and 4B, and the cutoff sizes for the biopsies were defined as 1 cm for K-TIRADS 4B and 1.5 cm for K-TIRADS 4A. The diagnostic performance and the rate of unnecessary biopsies of the modified K-TIRADS for detecting malignancy were compared with those of the 2016 K-TIRAD, which were stratified by nodule size (with a threshold of 2 cm). @*Results@#A total of 1111 malignant nodules and 4597 benign nodules were included. The sensitivity, specificity, and unnecessary biopsy rate of the benign nodules were 94.9%, 24.4%, and 60.9% for the 2016 K-TIRADS; 91.0%, 39.7%, and 48.6% for the modified K-TIRADS 1; 84.9%, 45.9%, and 43.5% for the modified K-TIRADS 2; and 76.1%, 50.2%, and 40.1% for the modified K-TIRADS 3. For small nodules (1–2 cm), the diagnostic sensitivity of the modified K-TIRADS decreased by 5.2–25.6% and the rate of unnecessary biopsies reduced by 19.2–32.8% compared with those of the 2016 K-TIRADS (p 2 cm), the modified K-TIRADSs maintained a very high sensitivity for detecting malignancy (98%). @*Conclusion@#The modified K-TIRADSs significantly reduced the rate of unnecessary biopsies for small (1–2 cm) nodules while maintaining a very high sensitivity for malignancy for large (> 2 cm) nodules.

Pre-contoured reconstruction plate fabricated via three-dimensional printed bending support

A mandibular continuity defect can be repaired using either a prosthetic device or autogenous bone. A titanium reconstruction plate can be used with a localized or vascularized flap over the defect of the mandible. Unfortunately, the plate may fail due to plate exposure, screw loosening, fracture, or infection, and will need to be removed. Plate exposure though the skin or mucosa is one of the main reasons for failure. In the present work, the authors introduced a lingually positioned reconstruction plate fabricated via three-dimensional printed bending support. This custom reconstruction plate can avoid plate re-exposure as well as reduce surgical errors and operation time.