Several combinations of different skin tumors occuring one adjacent to the other or even in a single lesion have been described up to date. Collision tumors involving atypical fibroxanthoma and melanoma are extremely uncommon. Herein we present a case of melanoma associated with AFX and discuss on the usefulness of dermoscopy in the clinical diagnosis of collision tumors.

A 22-year-old female presented to the dermatology department with a 8-month history of blistering lesions over the left forearm and face. Most of the bullae and erosions were perfectly round and of nearly the same size. In absence of any obvious etiological, precipitating or aggravating factor, a provisional diagnosis of dermatitis artefacta (self-inflicted dermatological lesions) was made. A detailed anamnesis revealed that stress caused by her ex-boyfriend’s threats and apprehension of consequences prompted her to create the lesions using a hot spoon. The patients of dermatitis artefacta usually present to dermatologists as their pathology manifests as unexplained and variable cutaneous lesions which may go undiagnosed for a long time. It is important for the dermatologist to have a high index of suspicion to recognise the underlying psychopathology.

Background:Syphilitic alopecia is not common in patients with secondary syphilis. Though the clinical and histopathological findings of syphilitic alopecia have been described, the trichoscopy features are unknown yet.Main observation:A 42-year-old Chinese man was admitted to our clinic with a complaint of hair loss. The patient presented clinically with moth-eaten alopecia over the whole scalp without any previous discomfort or skin rashes. The serology for syphilis was positive. Trichoscopy showed black dots, focal atrichia, hypopigmentation of hair shaft and yellow dots.Conclusions:On the basis of trichoscopy, along with serology testing syphilitic alopecia can be differentiated from other hair loss diseases with similar clinical presentation.

Background:Vulval involvement is an uncommon extraintestinal manifestation of Crohn’s disease, and it is very rare in children. Patients with vulval CD typically present with erythema and edema of the labia majora, which can progresses to extensive ulcer formation. Vulval CD can appear before or after intestinal problems or it may occur simultaneously.Observation:We present a 15-years-old girl with bilateral labial hypertrophy which revealed a Crohn’s disease. The course of her lesion was independent of the intestinal disease and responded significantly to medical treatment including Mesalamine, corticosteroid and local care.Conclusions:We emphasize that although vulval involvement in childhood is uncommon, Crohn’s disease must be considered in the differential diagnosis of nontender, red, edematous lesions of the genital area.

Background:Cellular combinations in the same neoplasm can have intriguing physiopathological implications, which may be useful to better understand the biology of the diseases.Main observations:Urticaria pigmentosa in association with eruptive melanocytic nevi was observed in a female patient. Maculopapular lesions extended at the base of different melanocytic nevi and the histopathological examination revealed the presence of a mast cell population in the papillary and reticular dermis combined with overlying melanocytic nevi. The re-evaluation of a melanoma removed three years before revealed the presence of the same pathological features. Immunohistochemical assays showed a strong positivity to Giemsa, Toluidine blue and CD-117 in the mast cells, while a S-100 reaction was observed in the melanocytic population.Conclusions:We discuss possible pathogenetic linkage between cutaneous mastocytosis and melanoma.

Background:Cutaneous mosaicism is a possible cause of segmental skin diseases. Cutaneous leiomyomatosis represent a spectrum of conditions ranging from single lesions to disseminated wide distribution. Reed's syndrome, is an autosomal dominant disorder characterized by multiple cutaneous and uterine leiomyomas.Main observation:We observed a segmental cutaneous piloleimyomatosis type 1 in a 55-year old female who had an uterus extirpation because of uterine leiomyomas. The cutaneous lesions were moderately painful and localized on her left upper trunk. They presented as firm nodules and small plaques in a linear arrangement. Renal cancer was excluded.Conclusion:In patients with multiple cutaneous (pilo)leiomyomas a search for underlying systemic diseases is necessary in order to not miss benign or malignant tumors of internal organs.

Primary mucosal melanoma of the oral cavity is an exceedingly rare neoplasm which is estimated to comprise 1-2% of all oral malignancies. In contrast to cutaneous melanomas, the risk factors and pathogenesis are poorly understood. The predominate localization of primary oral melanoma is hard palate and maxillary alveolus. Dermoscopy may be utilized as an adjunctive tool in the clinical differential diagnosis of oral mucosal melanoma whenever the lesion is accessible with a dermoscope. Surgery is the mainstay of treatment, but it may be challenging depending on the location of the tumor within the oral cavity and its size. Adjuvant therapy with dacarbazine, platinum analogs, nitrosoureas and interleukin-2 have been utilized with low response rates. Imatinib may be effective for patients with with c-Kit gene mutations. Sunitinib and dasatinib have been reported effective in selected cases. Vemurafenib and dabrafenib are targeted agents for patients with BRAF mutation-positive melanoma. Ipilimumab, an anti-cytotoxic T-lymphocyte antigen 4 antibody and pembrolizumab, a monoclonal antibody targeting programmed death 1 receptor may be a feasible treatment option in patients with metastatic mucosal melanoma.