Since the late 1990s, online e-learning has offered unparalleled convenience and affordability, becoming increasingly popular among pathologists. Traditional learning theories have been successfully applied to web/mobile-based learning systems, with mobile technologies even enhancing conventional offline education. In cytopathology, hands-on microscope training has traditionally been paramount, complemented by real-case presentations and lectures. However, the coronavirus disease 2019 (COVID-19) pandemic disrupted regular academic activities, making online e-learning platforms essential. We designed a web/mobile-based learning platform to enhance continued medical education in cytopathology at various levels, particularly during the era of COVID-19 and beyond. Since 2021, we have integrated curriculum materials, virtual education files, and whole-slide images (WSIs) of cytopathology, submitted from over 200 institutions across Korea, with the support of numerous instructors. We develop a new e-learning platform named “CytoAcademy” composed of a basic session for each organ and level across the range of morphologic findings; on-demand lectures to enhance cytopathologic knowledge; WSI archives that allow users to explore various histologically confirmed cases; and a self-assessment test to help organize diagnostic knowledge acquired through the web/mobile-friendly learning system. The platform provides not just an opportunity to achieve a correct diagnosis, but also a learning experience based on problem-solving point. Members interact, identify their deficiencies, and focus on specific educational materials. In this manner, all participants can actively engage in creating and maintaining knowledge and foster a proactive approach to learning.

Since the late 1990s, online e-learning has offered unparalleled convenience and affordability, becoming increasingly popular among pathologists. Traditional learning theories have been successfully applied to web/mobile-based learning systems, with mobile technologies even enhancing conventional offline education. In cytopathology, hands-on microscope training has traditionally been paramount, complemented by real-case presentations and lectures. However, the coronavirus disease 2019 (COVID-19) pandemic disrupted regular academic activities, making online e-learning platforms essential. We designed a web/mobile-based learning platform to enhance continued medical education in cytopathology at various levels, particularly during the era of COVID-19 and beyond. Since 2021, we have integrated curriculum materials, virtual education files, and whole-slide images (WSIs) of cytopathology, submitted from over 200 institutions across Korea, with the support of numerous instructors. We develop a new e-learning platform named “CytoAcademy” composed of a basic session for each organ and level across the range of morphologic findings; on-demand lectures to enhance cytopathologic knowledge; WSI archives that allow users to explore various histologically confirmed cases; and a self-assessment test to help organize diagnostic knowledge acquired through the web/mobile-friendly learning system. The platform provides not just an opportunity to achieve a correct diagnosis, but also a learning experience based on problem-solving point. Members interact, identify their deficiencies, and focus on specific educational materials. In this manner, all participants can actively engage in creating and maintaining knowledge and foster a proactive approach to learning.

Since the late 1990s, online e-learning has offered unparalleled convenience and affordability, becoming increasingly popular among pathologists. Traditional learning theories have been successfully applied to web/mobile-based learning systems, with mobile technologies even enhancing conventional offline education. In cytopathology, hands-on microscope training has traditionally been paramount, complemented by real-case presentations and lectures. However, the coronavirus disease 2019 (COVID-19) pandemic disrupted regular academic activities, making online e-learning platforms essential. We designed a web/mobile-based learning platform to enhance continued medical education in cytopathology at various levels, particularly during the era of COVID-19 and beyond. Since 2021, we have integrated curriculum materials, virtual education files, and whole-slide images (WSIs) of cytopathology, submitted from over 200 institutions across Korea, with the support of numerous instructors. We develop a new e-learning platform named “CytoAcademy” composed of a basic session for each organ and level across the range of morphologic findings; on-demand lectures to enhance cytopathologic knowledge; WSI archives that allow users to explore various histologically confirmed cases; and a self-assessment test to help organize diagnostic knowledge acquired through the web/mobile-friendly learning system. The platform provides not just an opportunity to achieve a correct diagnosis, but also a learning experience based on problem-solving point. Members interact, identify their deficiencies, and focus on specific educational materials. In this manner, all participants can actively engage in creating and maintaining knowledge and foster a proactive approach to learning.

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.

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.

Low-grade myofibroblastic sarcoma (LGMS) is a rare spindle cell tumor with indolent course. Due to rarity and low-grade histologic features of LGMS, accurate diagnosis is challenging. We report a 63-year-old female patient with a three-month history of a 3.1 cm×2.5 cm sized, firm, skin-colored, painless, protruding left back mass. Initial excisional biopsy was performed and the mass was diagnosed as nodular fasciitis. After 18 months after excision, the mass recurred with pain and grew larger. Considering the clinical manifestations, diagnostic impression was changed as dermatofibrosarcoma protuberans not nodular fasciitis. Second wide excision was performed and the histopathology revealed proliferative atypical spindle cells with moderate nuclear atypia and a distinctive whorling pattern, which is suggestive of low-grade sarcoma. Additional computed tomography and positron emission tomography revealed no metastasis and suspicious residual viable malignant tissue. To remove suspicious residual tumor, third wide excision were performed and the diagnosis confirmed as LGMS. A microscopically clear resection was achieved with deep and lateral safety margin 0.6 cm each. Despite of postoperative radiotherapy with 35 times, recurrence of the tumor and lung metastasis was found after 7 months later. LGMS rarely metastasizes and occurs most commonly in the head and neck region. Thus, we report a rare case of LGMS on back which repeated localized recurrence and regional lung metastasis occurred despite wide excision and adjuvant radiotherapy.

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.

Total knee arthroplasty is a surgical treatment for end-stage osteoarthritis of the knee. Postoperative lower limb alignment is one of the factors determining the long-term prognosis after total knee arthroplasty. Navigation-assisted surgery can be used to achieve an accurate lower limb alignment. Particular situations, such as severe extra-articular deformity in the femur or tibia and retained hardware, are a good indication for navigation-assisted surgery. On the other hand, thorough preoperative planning and an understanding of each steps of surgery are necessary to perform total knee arthroplasty successfully in these special cases. In this review article, preoperative radiological measurements and surgical planning for extra-articular deformity correction will be elucidated. The surgical steps and necessary instruments for navigation-assisted total knee arthroplasty will be described in cases of extra-articular deformity or retained hardware. A literature review showed that the radiological and clinical results after total knee arthroplasty using navigation in osteoarthritis with extraarticular deformity were good. Therefore, it is essential to use navigation when performing total knee arthroplasty in patients with extraarticular deformity or retained hardware.

Patients undergoing hemodialysis are susceptible to sarcopenia. As intracellular reservoirs of water, skeletal muscles are important contributors to intradialytic hypotension. This study was designed to determine the role of skeletal muscle mass in intradialytic hypotension. Methods: In a cross-sectional study, the body composition of 177 patients was measured immediately after hemodialysis using bioelectrical impedance analysis. The parameters measured were skeletal muscle mass, intracellular and extracellular water contents, total body water, and cell-membrane functionality (in phase angle at 50 kHz). Data from laboratory tests, chest radiography, measurements of handgrip strength and mid-arm circumference, and questionnaires were collected. The main outcome was intradialytic hypotension, defined as more than two episodes of hypotension (systolic blood pressure of <90 mmHg) with intervention over the 3 months following enrollment. Logistic regression models including each parameter related to sarcopenia were compared with a clinical model. Results: Patients with a low ratio of skeletal muscle mass to dry body weight (SMM/WT) had a higher rate of intradialytic hypotension (40.7%). Most low-SMM/WT patients were female, obese, diabetic, and had a lower handgrip strength compared with the other patients. In the high-SMM/WT group, the risk of intradialytic hypotension was lower, with an odds ratio of 0.08 (95% confidence interval [CI], 0.02–0.28) and adjusted odds ratio of 0.06 (95% CI, 0.01–0.29). Conclusion: Measurement and maintenance of skeletal muscle can help prevent intradialytic hypotension in frail patients undergoing hemodialysis.