Background: Comprehensive studies on the tumor burden of soft-tissue sarcoma (STS) by anatomical site are lacking in Asian populations. Objective: To investigate the anatomical distribution of STS via relative tumor density (RTD) in a Korean cohort. Methods: The RTDs of patients with STS at a single-institution from 2007–2022 were retrospectively analyzed. To describe the STS locations, the body was divided into 4 anatomical sites, and the RTD of each was calculated to the compare topographic tumor burden. Results: Fifty-nine cases in 58 individuals, 35 male (60.3%) and 23 female (39.7%), with a mean age of 56.5±20.4 were analyzed. Overall, the most frequent STS site was the lower extremity (LE, n=22, 37.3%), and the highest RTD was in the head and neck (H&N, 2.44; 95% confidence interval, 1.39–3.77). Dermatofibrosarcoma protuberans (DFSP), Kaposi’s sarcoma (KS), and angiosarcoma (AS) accounted for 76.3% of all the cases. DFSP, KS, and AS showed significantly higher RTD on the trunk (2.55, p=0.025), LE (3.88, p<0.001), and H&N (7.42, p<0.001), respectively, than elsewhere. Conclusion Each STS displays topographic variability and produces different topographic tumor burdens by body site in an Asian population.

Background: A picosecond laser irradiation technique has presented satisfactory cosmetic outcomes for the treatment of various pigmented lesions. We aimed to evaluate the clinical results of a picosecond neodymiumdoped:yttrium aluminum garnet (Nd:YAG) (PSNY) laser for the treatment of various pigmented lesions and to compare them with the results of a conventional Q-switched Nd:YAG laser. Methods: A retrospective review of subjects treated with a PSNY laser was performed. Clinical improvement was assessed by two blinded dermatologists using a 5-point Global Assessment Scale (GAS). Adverse events were also assessed. Results: Forty-eight patients were treated with a dual-wavelength (532-nm and/or 1,064-nm) PSNY laser. Sixteen of the 48 patients (33.3%) experienced more than 50% improvement after the PSNY treatment. Patients with café-au-lait macule showed the greatest improvement, which was fair to good (GAS, 3.80 ± 0.76). Patients with postinflammatory hyperpigmentation received the highest number of treatment sessions (6.60 ± 3.44 times). The duration of follow-up was the longest in patients with Ota’s nevus (22.50 ± 5.44 weeks). There were no serious complications during the treatment period. Conclusion In our case series, it was concluded that a dual-wavelength 532-nm and 1,064-nm PSNY laser was safe and effective for the treatment of pigmented lesions in Korean patients.

Background: In a previous study, rhinoplasty rasp was shown an effective method for removal of button osteoma (BO) of the skull. Objective: In the present study, our experience was presented and surgical outcome using high-speed burr in surgery for BO evaluated. Methods: The register-based surgery reports of patients who underwent local excision of BO (2010∼2023) at a single institution were reviewed. Demographics, photodocumentation, radiologic examinations, pathology reports, data of scar prevention, and surgical outcome in the BO study cohort were analyzed. Results: A total of 20 BO lesions in 18 patients (14 females and four males; mean age of 52.4±14.3 years) who underwent surgery using high-speed burr were assessed. The mean size of BO was 9.3 mm (range, 5∼17 mm).Most of the BOs were located on the forehead (19/20, 95.0%), which was associated with the course of the supratrochlear (n=13) or supraorbital nerve (n=6). Minimal hematoma was complicated in three patients (16.7%).Delayed complications, recurrence, and severe scarring during the mean follow-up of 3.1±3.5 months were not reported. Conclusion The use of high-speed burr for surface smoothening may provide good surgical results in minimally invasive BO surgery.

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 (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.

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.

Background: The exact definition of sensitive skin is not established yet. Since its high prevalence and significant influence on quality of life, it has become an important topic of research. Among various ingredients, conditioned media from umbilical cord blood-derived mesenchymal stem cells (UCB-MSC-CM) can be a promising source for the treatment of sensitive skin. Objective: We evaluated the efficacy and safety of UCB-MSC-CM on patients with sensitive skin. Methods: We designed a randomized, single blinded, prospective, split-face comparison study and enrolled thirty patients. All patients underwent nonablative fractional laser over the entire face before UCB-MSC-CM or normal saline was applied. Each facial area was randomly assigned to undergo treatment with either UCB-MSC-CM or normal saline. We performed three sessions at two-week intervals, and final results were assessed on six weeks after the last session. As an outcome measure, we evaluated a five-point global assessment scale, transepidermal water loss (TEWL), erythema index (EI) and Sensitive Scale-10. Twenty seven subjects were included in final analysis. Results: The treated side exhibited greater improvement compared to the untreated side based on a five-point global assessment scale. TEWL, EI of the treated side were significantly lower than those of the untreated side throughout study period. Sensitive Scale-10 was significantly improved after treatment. Conclusion The application of UCB-MSC-CM resulted in improved skin barrier function and reduced inflammatory responsiveness, which could provide beneficial effect on sensitive skin.