BackgroundAn epidermal cyst is a common keratin-filled epithelial-lined cyst. The treatment of choice for epidermal cysts is surgical excision. If the cyst becomes ruptured, incision and drainage with oral antibiotic therapy or intralesional steroid injection are required.ObjectiveTo analyze the dermoscopic features that can differentiate between ruptured and unruptured epidermal cysts.MethodsThe clinical and dermoscopic features of the pathologically confirmed epidermal cysts of two subgroups of 38 patients, 20 with unruptured cysts and 18 with ruptured cysts, were reviewed.ResultsWith regard to the dermoscopic features, an ivory- white background color and punctum were commonly found in both groups (p>0.05). The unruptured-cyst group showed higher frequencies of pore sign (p<0.05), blue-white veil (p>0.05), no vascular structure, and arborizing telangiectasia (p<0.05), but the ruptured-cyst group usually had red lacunae (p>0.05) and peripheral linear branched vessels (with an erythematous rim) (p<0.05).ConclusionDermoscopy is helpful in differentiating between ruptured and unruptured epidermal cysts.

Degos disease, also referred to as malignant atrophic papulosis, was first described in 1941 by Köhlmeier and was independently described by Degos in 1942. Degos disease is characterized by diffuse, papular skin eruptions with porcelain-white centers and slightly raised erythematous telangiectatic rims associated with bowel infarction. Although the etiology of Degos disease is unknown, autoimmune diseases, coagulation disorders, and vasculitis have all been considered as underlying pathogenic mechanisms. Approximately 15% of Degos disease have a benign course limited to the skin and no history of gastrointestinal or central nervous system (CNS) involvement. A 29-year-old female with history of systemic lupus erythematosus (SLE) presented with a 2-year history of asymptomatic lesions on the dorsum of all fingers and both knees. The patient had only skin lesions and no gastrointestinal or CNS vasculitis symptoms. Her skin lesions were umbilicated, atrophic porcelain-white lesions with a rim of erythema. On the basis of clinical, histologic, and laboratory findings, a diagnosis of Degos-like lesions associated with SLE was made. The patient had been treated for SLE for 7 years. Her treatment regimen was maintained over a 2 month follow-up period, and the skin lesions improved slightly with no development of new lesions.

Lichen aureus (LA) is a variant of pigmented purpuric dermatosis that is characterized clinically by rust macules, papules or plaques, mainly on the legs. In some cases, LA can be difficult to be distinguished from nummular eczema (NE) with the naked eye. Dermoscopy can be applied to skin lesions, revealing additional features that can be highly valuable for correct diagnosis. This study was conducted to investigate characteristic dermoscopic findings of LA and to identify distinctive features that can differentiate it from NE. Fourteen LA patients and 14 NE patients diagnosed by skin biopsy were enrolled. Skin lesions were evaluated via polarized dermoscopy. On dermoscopy, "coppery orange diffuse coloration of background", "round to oval red globules", "gray dots", and "networks of brownish to gray interconnected lines" were more commonly seen in LA (100%, 92.9%, 42.9% and 64.3%, respectively) compared with NE. "Scales", "shiny yellow clods" and "irregularly distributed brownish-red globules" were more commonly seen in NE (100%, 85.7% and 57.1%, respectively) compared with LA. Dermoscopy provides valuable information for diagnosis of LA and aids in differentiating it from NE.

BackgroundTsutsugamushi disease is an acute, febrile, infectious disease caused by Orientia tsutsugamushi. Several studies investigating the histopathologic findings of eschars in tsutsugamushi disease reported leukocytoclastic vasculitis and neutrophil infiltration as the major findings. However, these findings may result from secondary changes following tissue necrosis. The histopathologic findings of perieschar lesions may be important to understand the primary changes associated with tsutsugamushi disease.ObjectiveTo investigate characteristic histopathologic features of perieschar lesions and suppose the mechanism of vascular pathophysiological changes associated with tsutsugamushi disease.MethodsWe analyzed histopathological slides of perieschar lesions in 12 patients diagnosed with tsutsugamushi disease.ResultsIn the epidermis, exocytosis of mononuclear cells (75.0%) and basal vacuolar changes (66.7%) were frequent. In the dermis, perivascular, interstitial, and perineural mononuclear cell infiltration (100.0%, 83.3%, and 83.3%, respectively), as well as thrombosis (83.3%), atypical lymphocyte infiltration (91.7%), and mitotic figures (83.3%) were commonly seen. Lymphocytic vasculitis and mononuclear cell infiltration around eccrine glands were found in all cases, but eosinophil infiltration was only found in one patient (8.3%). However, the characteristic findings of eschar lesions, such as leukocytoclastic vasculitis and neutrophil infiltration, were not found in perieschar lesions.ConclusionThe major histopathologic findings in the perieschar lesions of tsutsugamushi disease were lymphocytic vasculitis and atypical lymphocytic infiltration, mimicking lymphoma. Therefore, we suggest that this lesion should be added to the list of pseudolymphomas. To observe these characteristic histopathologic features, we also recommend that skin biopsies should be performed on perieschar lesions, not eschar lesions.

Spark's nevus is a compound word composed of Spitz nevus and Clark's nevus. It is one of the combined melanocytic nevi which is more common in female and usually presents as a sharp circumscribed hyperpigmented macule on the lower extremities. On histopathologic findings, both cytologic features of Spitz nevus characterized as large spindle or epithelioid melanocytes containing large nuclei with abundant cytoplasm, and architecture of Clark's nevus characterized as elongation of rete ridges, bridging of the nests, concentric and lamellar fibrosis can be seen. A 24-year-old female presented with an asymptomatic, solitary, dark-brown-colored papule surrounded by brownish patch that looked similar to dysplastic nevus or malignant melanoma on the buttock. On dermoscopic examination, it showed brown-to-black globules, diffuse homogenous pigmentation with blue-white structures, and a surrounding brownish reticular pattern that faded away. On histopathologic findings, overall asymmetrical structure, epithelioid large melanocytes containing large nuclei with abundant cytoplasm, and Kamino body were seen in the central portion. Also, lentiginous hyperplasia, bridging of the nests composed of melanocytes containing foamy cytoplasm, concentric and lamellar fibrosis along with the elongation of rete ridge, and perivascular lymphocytic infiltration were seen in the peripheral portion. The diagnosis of Spark's nevus was made. Following its definition, this combined nevus is diagnosed histopathologically, but the clinicodermoscopic features have not been well described. Herein, we report a case of Spark's nevus in which dermoscopy was helpful for differentiating it from malignant melanoma. (Ann Dermatol 32(3) 233∼236, 2020