Clear cell hidradenoma is a skin adnexal tumor originating from eccrine glands. The risk of local recurrence after surgical resection exceeds 50%, and 6-19% of cases are malignant. The rarity of clear cell hidradenoma and its diverse histological findings make this type of tumor a diagnostic challenge. We present a case of recurrent clear cell hidradenoma of the posterior neck in a 70-year-old woman. The tumor recurred once after complete excision, and did not recur again after 1-cm wide excision and reconstruction with a local bilobed flap. Recurrent clear cell hidradenomas are activated by surgical stimulation, increasing the risk for metastasis. Therefore, we suggest that wide excision with confirmation of a tumor-free margin by frozen-section biopsy should be the first-line treatment for recurrent benign clear cell hidradenoma.

Clear cell hidradenoma is a skin adnexal tumor originating from eccrine glands. The risk of local recurrence after surgical resection exceeds 50%, and 6-19% of cases are malignant. The rarity of clear cell hidradenoma and its diverse histological findings make this type of tumor a diagnostic challenge. We present a case of recurrent clear cell hidradenoma of the posterior neck in a 70-year-old woman. The tumor recurred once after complete excision, and did not recur again after 1-cm wide excision and reconstruction with a local bilobed flap. Recurrent clear cell hidradenomas are activated by surgical stimulation, increasing the risk for metastasis. Therefore, we suggest that wide excision with confirmation of a tumor-free margin by frozen-section biopsy should be the first-line treatment for recurrent benign clear cell hidradenoma.

Objectives: This study was conducted to systematically summarize trends in research concerning patients with coronavirus disease 2019 (COVID-19) as reported in Korean medical journals. Methods: We performed a literature search of KoreaMed from January 2020 to September 2022. We included only primary studies of patients with COVID-19. Two reviewers screened titles and abstracts, then performed full-text screening, both independently and in duplicate. We first identified the 5 journals with the greatest numbers of eligible publications, then extracted data pertaining to the general characteristics, study population attributes, and research features of papers published in these journals. Results: Our analysis encompassed 142 primary studies. Of these, approximately 41.0% reported a funding source, while 3.5% disclosed a conflict of interest. In 2020, 42.9% of studies included fewer than 10 participants; however, by 2022, the proportion of studies with over 200 participants had increased to 40.6%. The most common design was the cohort study (48.6%), followed by case reports/series (35.2%). Only 3 randomized controlled trials were identified. Studies most frequently focused on prognosis (58.5%), followed by therapy/intervention (20.4%). Regarding the type of intervention/exposure, therapeutic clinical interventions comprised 26.1%, while studies of morbidity accounted for 13.4%. As for the outcomes measured, 50.7% of studies assessed symptoms/clinical status/improvement, and 14.1% evaluated mortality. Conclusions Employing a systematic approach, we examined the characteristics of research involving patients with COVID-19 that was published in Korean medical journals from 2020 onward. Subsequent research should assess not only publication trends over a longer timeframe but also the quality of evidence provided.