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.

Different progression pattern between acral and nonacral melanoma: A retrospective, comparative, clinicoprognostic study of 492 cases of primary cutaneous melanoma according to tumor site.

BACKGROUND: There are limited data regarding the difference in progression pattern between acral melanoma and nonacral melanoma. AIMS: The objectives of this study were to compare the progression pattern between acral and nonacral melanoma and evaluate its impact on clinical outcomes. METHODS: Clinical and histopathological features, survival outcomes and prognostic factors of 492 patients with acral melanoma or nonacral melanoma were retrospectively evaluated using the Asan Medical Center database. RESULTS: The male-to-female ratio and the mean age was 1:0.92 and 60.2 years for acral melanoma (n = 249), and 1:0.85 and 58.4 years for nonacral melanoma (n = 243), respectively. The demographic difference was not significant. Although prediagnosis duration was longer and the advanced stage was more common in acral melanoma than that in nonacral melanoma, the vertical growth phase was more common in nonacral melanoma than that in acral melanoma, whereas, the horizontal diameter is longer in acral melanoma than that in nonacral melanoma. Dissemination to lymph nodes was more common in acral melanoma than that in nonacral melanoma. Lymph node involvement was associated with deeper Breslow thickness in nonacral melanoma but not in acral melanoma. The degree of correlation of prediagnosis duration with horizontal diameter was remarkable in acral melanoma, but with Breslow thickness in nonacral melanoma. Overall survival was worse in acral melanoma than that in nonacral melanoma. The prognostic value of Breslow thickness was more remarkable in nonacral melanoma than that in acral melanoma. LIMITATIONS: This study is a retrospective, single-center design. CONCLUSION: Acral melanoma has a longer radial growth phase compared with nonacral melanoma. However, acral melanoma is commonly associated with lymph node dissemination which contributed to worse survival in acral melanoma than nonacral melanoma.

Primary cutaneous extranodal natural killer/T-cell lymphoma presenting as bilateral erythematous patches on the arms.

Natural killer/T-cell lymphoma is a rare, Epstein-Barr virus-associated type of cytotoxic lymphoma thatpresents mainly in the nasal cavity and its vicinity. Very few cases of primary cutaneous extranodal natural killer/T-cell lymphoma have been reported till date. All the previously reported cases of primary cutaneous extranodalnatural killer/T-cell lymphoma presented as lesions resembling cellulitis, subcutaneous nodules or ulcers. We report a rare case which presented as erythematous and purpuric round patches on the arms and was finally diagnosed as primary cutaneous extranodalnatural killer/T-cell lymphoma, following a skin biopsy. The atypical patchy lesions presented a diagnostic challenge. We herein describe this clinically novel atypical patch-like presentation of primary cutaneous extranodalnatural killer/T-cell lymphoma together with the key histopathologic features and highlights of the previously reported cases.

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

BACKGROUND: Dermatofibroma sometimes clinically presents as a nodular lesion without gross skin surface change. Clinicopathologic features of this variant of dermatofibroma have not been evaluated. AIMS: To assess clinicopathologic features of dermatofibroma 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 dermatofibroma. RESULTS: Dermatofibroma without gross skin surface change was associated with a shorter pre-diagnosis duration than conventional dermatofibroma. Increase in size during the pre-diagnosis period was significantly more frequent in the conventional type. In addition, these dermatofibromas 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 dermatofibromas without gross skin surface change were found histologically to be "subcutaneous" or "deep-penetrating dermatofibroma". Subcutaneous extension was more frequent in these dermatofibromas 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 dermatofibroma without gross skin surface change is a variant type with distinct clinical and histological features that distinguish them from conventional dermatofibroma.

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.