Objectives: Since protecting patients’ privacy is a major concern in clinical research, there has been a growing need for privacy-preserving data analysis platforms. For this purpose, a federated learning (FL) method based on the Observational Medical Outcomes Partnership (OMOP) common data model (CDM) was implemented, and its feasibility was demonstrated. Methods: We implemented an FL platform on FeederNet, which is a distributed clinical data analysis platform based on the OMOP CDM in Korea. We trained it through an artificial neural network (ANN) using data from patients who received steroid prescriptions or injections, with the aim of predicting the occurrence of side effects depending on the prescribed dose. The ANN was trained using the FL platform with the OMOP CDMs of Kyung Hee University Medical Center (KHMC) and Ajou University Hospital (AUH). Results: The area under the receiver operating characteristic curves (AUROCs) for predicting bone fracture, osteonecrosis, and osteoporosis using only data from each hospital were 0.8426, 0.6920, and 0.7727 for KHMC and 0.7891, 0.7049, and 0.7544 for AUH, respectively. In contrast, when using FL, the corresponding AUROCs were 0.8260, 0.7001, and 0.7928 for KHMC and 0.7912, 0.8076, and 0.7441 for AUH, respectively. In particular, FL led to a 14% improvement in performance for osteonecrosis at AUH. Conclusions FL can be performed with the OMOP CDM, and FL often shows better performance than using only a single institution's data. Therefore, research using OMOP CDM has been expanded from statistical analysis to machine learning so that researchers can conduct more diverse research.

Leiomyosarcoma (LMS) within the scrotum is a rare malignant genitourinary tumor in adults. Due to its rarity, a consensus on a clear approach to diagnosis and treatment guidelines has not yet been reached. We present a case of a paratesticular LMS in a 64-yearold man with a painless swelling of the right scrotum. Scrotal ultrasound and pelvic MRI were performed and revealed an extratesticular mass with a heterogeneous appearance.The patient underwent a right radical orchiectomy, and the mass was confirmed to be LMS, originating from the right spermatic cord. Preoperative diagnosis of LMS is challenging since it has overlapping clinical and imaging features with other sarcomas. MRI is a valuable imaging modality for the definitive characterization of the tumor. To provide timely and appropriate treatment, the correlation of the patient’s clinical information and imaging findings is necessary.

A 51-year-old man was referred for a skin defect with paresthesia and decreased pain in his right ala. He had a history of herpes zoster infection 3 weeks previously. Excisional biopsy and culture showed no evidence of skin malignancy or infection. He was diagnosed with trigeminal trophic syndrome (TTS) after herpes zoster infection. A two-stage folded nasolabial flap was used to reconstruct the defect. The patient was satisfied with the cosmetic outcomes of surgery, and there was no evidence of recurrence during the follow-up. TTS, a rare skin condition that presents with paresthesia, anesthesia, and facial ulceration, occurs after trigeminal nerve injury, which can be caused by herpes zoster infection in rare cases. TTS is an often-persistent condition with a high recurrence rate, causing cosmetic problems. Some surgical methods have been attempted, but our case presents the first use of a folded nasolabial flap to treat TTS. The flap was symmetric, without any nostril collapse. It is also noteworthy that the outcome was excellent with only a skin flap that did not use a bony framework. Herein, we report a rare case of TTS that occurred after herpes zoster infection and was successfully treated with a folded nasolabial flap.

Head and neck cutaneous metastasis of advanced gastric cancer is uncommon, and scalp metastasis is particularly rare. We present the case of a 60-year-old man who was diagnosed with cutaneous metastasis on the scalp originating from advanced gastric cancer. The patient was referred to the plastic surgery department for a scalp mass near the hairline. He had been diagnosed with advanced gastric cancer and undergone total gastrectomy and Roux esophagojejunostomy 3 years previously. The differential diagnosis for a single flesh-colored nodule on the scalp included benign tumors such as epidermal cyst or lipoma; therefore, the patient underwent excision and biopsy. In the operative field, the mass was found to be located in the frontalis muscle. The biopsy result showed that the mass was a metastatic lesion of advanced gastric cancer. Whole-body computed tomography revealed a gastric tumor with blood vessel infiltration, peritoneal carcinomatosis, liver metastasis, and multiple disseminated subcutaneous metastases. Although scalp metastasis originating from an internal organ is extremely rare, plastic surgeons should always consider a metastatic lesion in the differential diagnosis if a patient with a scalp lesion has a history of malignant cancer.

Head and neck cutaneous metastasis of advanced gastric cancer is uncommon, and scalp metastasis is particularly rare. We present the case of a 60-year-old man who was diagnosed with cutaneous metastasis on the scalp originating from advanced gastric cancer. The patient was referred to the plastic surgery department for a scalp mass near the hairline. He had been diagnosed with advanced gastric cancer and undergone total gastrectomy and Roux esophagojejunostomy 3 years previously. The differential diagnosis for a single flesh-colored nodule on the scalp included benign tumors such as epidermal cyst or lipoma; therefore, the patient underwent excision and biopsy. In the operative field, the mass was found to be located in the frontalis muscle. The biopsy result showed that the mass was a metastatic lesion of advanced gastric cancer. Whole-body computed tomography revealed a gastric tumor with blood vessel infiltration, peritoneal carcinomatosis, liver metastasis, and multiple disseminated subcutaneous metastases. Although scalp metastasis originating from an internal organ is extremely rare, plastic surgeons should always consider a metastatic lesion in the differential diagnosis if a patient with a scalp lesion has a history of malignant cancer.

Isolated head and neck metastasis of renal cell carcinoma (RCC) is relatively rare and metastasis to the temple area is very rare. Here, we present the case of a 51-year-old man who was diagnosed with RCC 2 years earlier and had a contralateral metastatic temple area lesion. The patient who was diagnosed with renal cell cancer and underwent a nephrectomy 2 years ago was referred to the plastic surgery department for a temple mass on the contralateral side. In the operative field, the mass was located in the temporalis muscle with a red-to-purple protruding shape. Biopsy of the mass revealed a metastatic RCC lesion. Computed tomography imaging showed a lobulated, contoured enhancing lesion. Positron emission tomography/computed tomography imaging showed high-fluorodeoxyglucose uptake in the right temporalis muscle. The patient underwent wide excision of the metastatic RCC including the temporalis muscle at the plastic surgery department. Skeletal muscle metastasis of head and neck lesions is extremely rare in RCC. Isolated contralateral temporalis muscle metastasis in RCC has not been previously reported in the literature. If a patient has a history of malignant cancer, plastic surgeons should always consider metastatic lesions of head and neck tumors. Because of its high metastatic ability and poor prognosis, it is very important to keep this case in mind.

Background: The reconstruction of large full-thickness alar defects requires complex surgical procedures that are usually performed in two stages, with concomitant disadvantages in terms of patient trauma, surgical risk, and cost. This study presents a functional folded nasolabial island flap (FNIF) that can be used to repair large-sized full-thickness alar defects in a straightforward manner. Methods: This retrospective study included seven patients who received a FNIF for a full-thickness alar defect between January 2007 and December 2020. The FNIF is different from the conventional nasolabial flap in that it is folded and twisted to achieve nostril reconstruction with a satisfactory three-dimensional mucosal lining in a single stage. The cosmetic and functional results of FNIF were evaluated by both patients and physicians. Results: The age ranged from 51 to 82 years (mean, 65.6 years). The causes of the defects were squamous cell carcinoma, basal cell carcinoma, and trigeminal trophic syndrome. The nostril lining did not collapse, there was no hypertrophic scarring, and air movement through the nostrils on the flap side was normal. Overall, FNIF produced excellent aesthetic and functional outcomes, with minimal patient discomfort. There were no postoperative complications. Conclusion Compared with existing reconstruction methods for large full-thickness alar defects, FNIF can easily achieve aesthetic and functional success in a single-stage procedure. It provides satisfactory results for both the patient and the surgeon.

A 46-year-old female presented a mass on her right lower leg where she had a burn injury due to moxibustion 10 years ago. Physical examination revealed a 3 cm sized firm nodule with tenderness. Plain radiograph was performed and it revealed well-defined calcifications. According to the history of moxibustion burn injury and the result of plain radiograph, dystrophic calcinosis cutis caused by burn injury was suspected. The patient underwent excisional biopsy using pre-,intra-, and postoperative ultrasonography (USG). There was no sign of recurrence. Herein, we report a case of a 46-year-old healthy woman who presented with single hard nodule on the right lower leg. Our case is worthwhile in two respects. First, It is first case report of dystrophic calcinosis cutis due to moxibustion burn injury. In east asian culture, moxibustion is a commonly conducted procedure and it often induces burn injury. Second, USG was used pre-, intra-, and post-operatively to assess the shape, location, and depth of the calcinosis cutis and to determine the surgical margin.

BACKGROUND: Cardiovascular risk remains increased despite optimal low density lipoprotein cholesterol (LDL-C) level induced by intensive statin therapy. Therefore, recent guidelines recommend non-high density lipoprotein cholesterol (non-HDL-C) as a secondary target for preventing cardiovascular events. The aim of this study was to assess the efficacy and tolerability of omega-3 fatty acids (OM3-FAs) in combination with atorvastatin compared to atorvastatin alone in patients with mixed dyslipidemia. METHODS: This randomized, double-blind, placebo-controlled, parallel-group, and phase III multicenter study included adults with fasting triglyceride (TG) levels ≥200 and <500 mg/dL and LDL-C levels <110 mg/dL. Eligible subjects were randomized to ATOMEGA (OM3-FAs 4,000 mg plus atorvastatin calcium 20 mg) or atorvastatin 20 mg plus placebo groups. The primary efficacy endpoints were the percent changes in TG and non-HDL-C levels from baseline at the end of treatment. RESULTS: After 8 weeks of treatment, the percent changes from baseline in TG (−29.8% vs. 3.6%, P<0.001) and non-HDL-C (−10.1% vs. 4.9%, P<0.001) levels were significantly greater in the ATOMEGA group (n=97) than in the atorvastatin group (n=103). Moreover, the proportion of total subjects reaching TG target of <200 mg/dL in the ATOMEGA group was significantly higher than that in the atorvastatin group (62.9% vs. 22.3%, P<0.001). The incidence of adverse events did not differ between the two groups. CONCLUSION The addition of OM3-FAs to atorvastatin improved TG and non-HDL-C levels to a significant extent compared to atorvastatin alone in subjects with residual hypertriglyceridemia.