Primary localized cutaneous nodular amyloidosis (PLCNA) is the rarest form of cutaneous amyloidosis, characterized by nodular deposits of light chain amyloids in the dermis and subcutaneous tissue, without apparent systemic involvement. One or several nodules are preferably located on the extremities, trunk, or face. The most useful stain for detecting amyloid fibrils is Congo red, which, when combined with polarized light, makes amyloid proteins appear apple-green under a microscope. Immunohistochemical staining can help identify the exact type of amyloid proteins. Although the exact etiology of PLCNA is unclear, removal of nodules by shaving or surgical excision has shown good results. To the best of our knowledge, only seven cases of PLCNA have yet been reported in the Korean literature. In three of these cases, the patients had lesions on the scalp. Herein, we present a case of a 34-year-old male with PLCNA on the scalp with all the results of immunohistochemical evaluation.

Background: Glomus tumors are benign mesenchymal neoplasms originating from the subcutaneous glomus body. It is often described as a painful nodule accompanied by tenderness and temperature sensitivity. Objective: To analyze the clinicopathologic features of glomus tumors and determine the correlations between the characteristics of glomus tumors and those of the patients. Methods: We reviewed the medical records and biopsy specimens of 29 cases of glomus tumors diagnosed between June 2006 and May 2021 at a single tertiary hospital. Results: The male to female ratio was 2.6:1, and the mean age of onset was 44.3 years. All cases presented with a solitary lesion, and the most common location was the fingernail (15 cases, 51.7%). Sixteen tumors (55.2%) were located in the digits, all of which were subungual tumors. Among these, nine tumors (56.3%) were observed in the nail bed, and seven (43.7%) were observed in the nail matrix. Thirteen patients (44.8%) had extradigital tumors.Histopathologically, 12 cases were solid glomus tumors (41.4%), 15 were glomangiomas (51.7%), and one was a glomangiomyoma (3.4%). Myxoid stromal changes were observed in nine cases (31.0%), all of which were subungual tumors. All tumors were removed. Postoperative nail deformities were observed in eight cases (50% of subungual tumors). Conclusion At our clinic, glomus tumors were commonly seen as solitary nodules accompanied by pain or tenderness. More than half of the tumors were located in the subungual area, mostly in the fingernails. Tumor removal alleviated the symptoms in most cases, but often resulted in residual nail dystrophy.

Neutrophilic urticarial dermatosis (NUD) clinically resembles urticaria but histopathologically represents a neutrophilic dermatoses. Affected patients develop erythematous macules, papules or slightly raised plaques lasting 24 to 48 hours. Histopathologic examination reveals an intense neutrophilic infiltration in the dermis with leukocytoclasia, but without fibrinoid necrosis of vessel walls. Clinical manifestations of NUD are similar to urticaria or Sweet’s syndrome, but it differs in that accompanying systemic symptoms like fever or arthralgia, and histologic features of dense neutrophilic infiltration in the dermis. A 69-year-old female patient presented with a one-day history of pruritic skin rashes and fever. Skin rashes appear erythematous patches and plaques on the whole body accompanied with multiple vesiculobullous lesions on both lower legs. Skin biopsy of lesion displayed interstitial neutrophilic infiltration in Indian file between collagen fiber, and leukocytoclasia. There were no clinical and laboratory findings that suspect of associated diseases. Herein, we report the first case of NUD developing vesiculobullous lesions.

Neutrophilic urticarial dermatosis (NUD) clinically resembles urticaria but histopathologically represents a neutrophilic dermatoses. Affected patients develop erythematous macules, papules or slightly raised plaques lasting 24 to 48 hours. Histopathologic examination reveals an intense neutrophilic infiltration in the dermis with leukocytoclasia, but without fibrinoid necrosis of vessel walls. Clinical manifestations of NUD are similar to urticaria or Sweet’s syndrome, but it differs in that accompanying systemic symptoms like fever or arthralgia, and histologic features of dense neutrophilic infiltration in the dermis. A 69-year-old female patient presented with a one-day history of pruritic skin rashes and fever. Skin rashes appear erythematous patches and plaques on the whole body accompanied with multiple vesiculobullous lesions on both lower legs. Skin biopsy of lesion displayed interstitial neutrophilic infiltration in Indian file between collagen fiber, and leukocytoclasia. There were no clinical and laboratory findings that suspect of associated diseases. Herein, we report the first case of NUD developing vesiculobullous lesions.

Background: Pityriasis lichenoides et varioliformis acuta (PLEVA), a type of pityriasis lichenoides disease, is an uncommon inflammatory cutaneous disorder of unknown etiology. PLEVA presents as acute inflammatory papules that progressively develop into erosions or necrotic crusts all over the body. Objective: This study aimed to analyze the clinicopathological findings of 39 patients with PLEVA at a tertiary referral center in Seoul, Korea. Methods: This was a retrospective and single-center study with a longitudinal section. Medical records and telephone interviews were used to review the data of patients diagnosed with PLEVA between 2006 and 2019. Results: This study included 39 patients with PLEVA (male: female=2.9:1). The mean age of onset was 30.1 years, and 20/39 (51%) patients were children or young adults (＜30 years old). The mean duration of the disease course was 8.9 months. The disease was associated with a wide spectrum of clinical features ranging from erythematous inflammatory papules to diffusely progressing ulcers or crusted lesions. Treatment modalities involved topical corticosteroids (67%), low-dose systemic corticosteroids (44%), systemic antibiotics (33%), narrow-band ultraviolet B treatment (18%), and observation (13%). Except in one case, there were no reports of intolerable comorbidity or severe side effects within the follow-up period. Conclusion PLEVA showed a male predominance and primarily occurred during childhood or young adulthood in our study cohort. PLEVA could be associated with cutaneous T-cell lymphoma. Various treatment modalities may be used according to the clinical severity, and most patients exhibited a good response to treatment.