Clinicopathological features and prognosis of pyoderma gangrenosum in Korea: A single centre, retrospective, observational study over 20 years

Background: Pyoderma gangrenosum is a rare autoinflammatory neutrophilic dermatosis that rapidly evolves. However, little is known about the clinicopathological features and prognosis of pyoderma gangrenosum. Aims: We aimed to document clinicopathologic and prognostic data of the patients with pyoderma gangrenosum. Methods: In this retrospective observational study, we reviewed case records of patients diagnosed with pyoderma gangrenosum between 1999–2019. Results: Fifty-three patients were identified by reviewing medical records for skin biopsy; of these, 37 were men and 16 were women. Mean age at onset was 43.3 ± 18.5 years. The most frequently affected area was the lower extremities (60.4%), followed by the head and neck (17.0%). The most common subtype was ulcerative (47.2%), followed by bullous (22.6%). 30 cases had underlying diseases and the most common were malignancy (24.5%), followed by inflammatory bowel diseases (18.9%). The proportion of cases with history of trauma were significantly higher in post-operative type (100%) as compared to the bullous type (8.3%). Histologic features of granulation tissue were frequently found in post-operative type (66.7%) and bullous type (58.3%). Granulomas were predominantly found in bullous type (58.3%). Age <60 years appeared to be significantly associated with multiple lesions. Partial-to-complete remission was observed in 40 cases (75.5%). Nine (17.0%) cases experienced recurrence with a median progression-free period of six months (interquartile range of 3.0–9.0 months). Cases with underlying hematologic disorders and the bullous subtype were significantly associated with early recurrence. Limitations: This study was a single-centre study with a retrospective design. Conclusion: Pyoderma gangrenosum appears to have ethnic differences. Underlying haematologic disorders and bullous subtype have a worse prognosis. However, the type of histopathology did not correlate with the clinical outcome of pyoderma gangrenosum.

Clinical and histological patterns of dermatofibroma without gross skin surface change: A comparative study with conventional dermatofibroma.

Backg round: Dermatofibroma sometimes clinically presents as a nodular lesion without gross skin surface change. Clinicopathologic features of this variant of dermatofi broma have not been evaluated. Aims: To assess clinicopathologic features of dermatofi broma presenting as a subcutaneous nodule. Methods: This study reviewed the clinical and histological features of 42 cases of subcutaneous dermatofibromas and compared them with 95 cases of conventional dermatofi broma. Results: Dermatofi broma without gross skin surface change was associated with a shorter pre-diagnosis duration than conventional dermatofi broma. Increase in size during the pre-diagnosis period was signifi cantly more frequent in the conventional type. In addition, these dermatofi bromas were more likely than the conventional type to occur in the head and neck region. Although tumor depth was deeper than in the conventional type, less than half of the dermatofi bromas without gross skin surface change were found histologically to be “subcutaneous” or “deep-penetrating dermatofi broma”. Subcutaneous extension was more frequent in these dermatofi bromas while focal stromal hyalinization and hemosiderin deposits were more common in the conventional type. Limitations: This study is a retrospective, single center design. Conclusion: The present study suggests that dermatofi broma without gross skin surface change is a variant type with distinct clinical and histological features that distinguish them from conventional dermatofi broma.

Comparison of acquired bilateral nevus of Ota-like macules in men and women.

Background: The clinical and histopathological characteristics of acquired bilateral nevus of Ota‑like macules in men are poorly documented due to its rarity. Aims: To compare the clinical and histopathological characteristics of acquired bilateral nevus of Ota‑like macules in men with the condition in women. Methods: We studied 11 men and 62 women, all with a clinical diagnosis of acquired bilateral nevus of Ota‑like macules. Biopsies were taken from 5 men and 10 women and their clinical and histopathological features were compared. Results: The most frequently affected site in men was the forehead [8 (73%) out of 11 patients]. Lesions on the forehead were more common in men than women (P = 0.001). In contrast to women, there was no apparent tendency of the lesions to become more blue with age in men. Concurrent melasma was observed in 14 (23%) out of 62 women, but not in men. Extra‑facial acquired dermal melanocytosis was noted in 2 (18%) out of 11 men and in none of the 62 women. Conclusion: Significant differences were noted between men and women in the appearance of concurrent pigmentary lesions and the distribution of lesions. Extra‑facial acquired dermal melanocytosis was noted in men.

Distribution of a pelagic tunicate, Salpa fusiformis in warm surface current of the eastern Korean waters and its impingement on cooling water intakes of Uljin nuclear power plant.

Impingement of a large amount of gelatinous plankton, Salpa fusiformis on the seawater intake system-screens in a nuclear power plant at Uljin was firstly recorded on 18th June 2003. Whole amount of the clogged animals was estimated were presumptively at 295 tons and the shortage of cooling seawater supply by the animal clogging caused 38% of decrease in generation capability of the power plant. Zooplankton collection with a multiple towing net during the day and at night from 5 to 6 June 2003 included various gelatinous zooplanktons known to be warm water species such as salps and siphonophores. Comparatively larger species, Salpa fusiformis occupied 25.4% in individual density among the gelatinous plankton and showed surface distribution in the depth shallower than thermocline, performing little diel vertical migration. Temperature, salinity and satellite data also showed warm surface current predominated over the southern coastal region near the power plant in June. The results suggested that warm surface current occasionally extended into the neritic region may transfer S. fusiformis, to the waters off the power plant. The environmental factors and their relation to ecobiology of the large quantity of salpa population that are being sucked into the intake channel of the power plant are discussed.