Dermatofibroma is one of the most common entities seen in dermatology clinical practice. Several clinical subtypes have nevertheless been described, all of them of uncommon occurrence. The authors present two rare clinical variants of dermatofibromas: congenital multiple clustered dermatofibroma (the presented case is the 4th congenital case to be reported so far) and multiple eruptive dermatofibromas developing in the setting of a Sjögren's syndrome. Since the uncommon subtypes may not be clinically evident, dermatologists should familiarize themselves with their main features and we advise a high level of clinical suspicion in order to reach the correct diagnosis.

Misdiagnosis and delay in diagnosing acral malignant melanoma are quite common and usually associated with a poor prognosis. Non-healing plantar ulcers, including diabetic feet ulcers, are a possible misdiagnosis, with reports of malignant melanoma cases mistaken for diabetic foot ulcers.A 54-year-old male patient, with Type 2 diabetes mellitus, was referred to our department with a painless, non-healing ulcer of 12 months' duration under the right fifth metatarsal bone. The ulcer had been managed for months as a diabetic foot ulcer with local wound care, antibiotics and pressure-relieving footwear. On clinical examination, there was a 2.5-cm diameter ulcer under the right fifth metatarsal head, extending to the fourth interdigital space, with a pigmented macule with irregular borders in the ulcer margins (Fig. 1). An incisional biopsy was taken from the lesion and the histopathological examination showed a malignant melanoma with a Breslow depth of 5.3 mm. Foot amputation was performed and further investigation revealed involvement of the inguinal lymph nodes. The patient died 8 months later with metastatic disease.Malignant melanoma accounts for approximately 4% of all skin cancers, although it causes around 79% of all skin cancer deaths [1]. Acral lentiginous melanoma is the most common melanoma type that presents on the plantar aspect of the foot. The misdiagnosis of acral melanoma is common, occurring in approximately 40% of all cases [2]. Acral melanoma is frequently misdiagnosed because of its less common location and absence of the classical signs of melanoma associated with the mnemonic aid 'ABCD' (asymmetry, border, colour, diameter); moreover, it is frequently ulcerated and amelanotic. Misdiagnosis and delay in diagnosis may lead to poor disease outcome. A retrospective review of plantar melanoma showed that misdiagnosis led to a 12-month mean delay of treatment and was associated with increased tumour thickness (5.0 vs. 1.5 mm) and lower 5-year survival rate (15.4 vs. 68.9%) [2]. In the (a) (b) (d) (c) FIGURE 1 Clinical aspect of the lesion: plantar ulcer under the right fifth metatarsal head, extending to the fourth interdigital space. Histological features of the tumour: (a) and (b) melanoma cells diffusely infiltrating the dermis [haematoxylin and eosin stain (H&E), · 4]; (c) and (d) higher magnification of the melanoma cells (Haematoxylin and eosin stain, · 40).

Proliferating trichilemmal tumor is a rare tumor originating in the external root sheath, that is usually found in the scalp of middle-aged or elderly females. Its histologic appearance may not correlate with its clinical behavior. In addition, there are no guidelines available for the treatment of these tumors, making its management a challenge for physicians. We report the case of a 53 year-old woman with a proliferating trichilemmal tumor on her nose, which is a very uncommon location for these lesions.

Breast cancer is the most frequently diagnosed life-threatening cancer in women and the leading cause of cancer death among them worldwide. It includes a heterogeneous collection of diseases with various histologically defined subsets, clinical presentations, responses to treatment and outcomes. We describe 2 cases of female patients with ductal breast carcinoma. Dermatologists may have an important role in diagnosing such diseases.

Urticarial vasculitis is a rare clinicopathologic entity characterized by urticarial lesions that persist for more than 24 hours and histologic features of leukocytoclastic vasculitis. Patients can be divided into normocomplementemic or hypocomplementemic. The authors report the case of a healthy 49-year-old woman with a 1-year history of highly pruritic generalized cutaneous lesions and finger clubbing. Laboratory tests together with histopathologic examination allowed the diagnosis of hypocomplementemic urticarial vasculitis, chronic hepatitis C and type II mixed cryoglobulinemia. The patient started symptomatic treatment and was referred to a gastroenterologist for management of the hepatitis C, with progressive improvement of the skin condition. The development of hypocomplementemic urticarial vasculitis in the context of chronic hepatitis C is exceedingly rare and possible pathogenic mechanisms are discussed.