Keratoacanthoma may be easily mistaken with squamous cell carcinoma, both clinically as well as histopathologically. However, only keratoacanthoma can regress spontaneously.We report a case of a patient with a exophytic, ulceraded, infiltrated lesion in their scalp that was initially diagnosed as a keratoacanthoma. The histopathologic examination confirmed the presence of squamous cell carcinoma, and the tomography of the skull showed that the cancer had spread within the cranium. A surgical excision with wide margins and rotation flap was conducted, followed by adjuvant chemotherapy and radiotherapy treatments.There are a great number of accounts of squamous cell carcinoma erroneously diagnosed as keratoacanthomas in the specialist literature, illustrating the difficulty in differentiating between them.While there is no established effective method to distinguish between the two conditions, surgical excision should be the treatment of choice.

Keywords: CARCINOMA, SQUAMOUS CELL, KERATOACANTHOMA, SURGERY

Introduction: Mohs Micrographic Surgery is a well-known and established method in the United States, and is currently considered the gold standard treatment in many cases involving cutaneous neoplasias. Since it was first described by Dr. Frederic E. Mohs, the micrographic surgery technique has been continuously changed and adapted to better suit the daily life needs of dermatologic surgeons. This article examines different and innovative Mohs Micrographic Surgery techniques.

Keywords: MOHS SURGERY, CARCINOMA, BASAL CELL, CARCINOMA, SQUAMOUS CELL

A case of pigmented basocellular carcinoma clinically mimicking a malignant lentigo melanoma in the temporal region of a black female patient is reported. Basal cell carcinoma rarely occurs in black patients. When present, however, it is the second most common malignant skin neoplasia, and is usually pigmented. When the face is affected in such patients, it is difficult to differentiate between malignant lentigo melanoma and basal cell carcinoma. Dermatoscopy is a very helpful diagnostic tool in these cases.

Keywords: CARCINOMA, BASAL CELL, MELANOMA, DERMOSCOPY

Dermoscopy is increasingly used to diagnose non-melanocytic skin tumors. Basal cell carcinoma presents some highly suggestive structures for its diagnosis. The presence of chrysalides-like structures is also frequently found in other benign and malignant skin tumors, and their significance in basal cell carcinoma has yet to be determined. HPV is a virus with oncogenic potential and its involvement in the pathogenesis of basal cell carcinomas is also not yet clearly understood.

Keywords: CARCINOMA, BASAL CELL, DERMOSCOPY, ONCOGENES

Merkel cell carcinomas are highly aggressive neuroendocrine skin tumors that have a poor prognosis. The authors present a case report and emphasize the importance of early diagnosis and treatment.

Keywords: CARCINOMA, MERKEL CELL, IMMUNOHISTOCHEMISTRY, SKIN

Introduction: The reconstruction of surgical defects resulting from the excision of tumors in the nose is a challenge for dermatologic surgeons due to its rigid structure and low mobility. The Mohs Micrographic Surgery technique allows the preservation of healthy tissue and leads to a smaller surgical wound. Objective: To demonstrate techniques for surgical correction of defects after removal of tumors of the nose through Mohs Micrographic Surgery, according to the anatomical location of the tumor. Methods: Descriptive study of patients operated on using Mohs Micrographic Surgery during the period 1996-2010. Patient images taken pre-, intra-, and post-operatively were analyzed with the aim of classifying the defect's anatomic location and the type of surgical reconstruction adopted. Results: 170 patients (totaling 203 lesions) were included in the study. The most common locations for tumors were (in descending order): nasal ala, dorsum, tip, and lateral wall. The advancement flap was the most common reconstruction type for lesions located in the lateral wall and in the nasal ala. Grafts were most often used in lesions located in the tip of the nose. Grafts and advancement flaps were more frequently used in the dorsum of the nose. Conclusions: The parameters that provide guidance on choosing the best reconstruction method must take into consideration the size and location of the surgical defect.

Keywords: MOHS SURGERY, CARCINOMA, BASAL CELL, CARCINOMA, SQUAMOUS CELL

Introduction: Mohs micrographic surgery is a treatment option that increases the cure rate in various types of skin cancer, offering greater tissue preservation and lower recurrence rates. Objective: To describe clinically and histologically the tumors operated on with Mohs micrographic surgery, and to draw correlations to the number of stages and the type of surgical reconstruction performed. The operations were performed at a private clinic in the municipality of Rio de Janeiro, Brazil that is a specialist center for this technique. Methods: Retrospective, observational, cross-sectional/transversal study was carried out based on the review of medical records. Results: A study was conducted of 93 tumors in 84 patients, operated on between April 2010 and August 2012, and followed up with until August 2013 (12 to 42 months). Findings: 47.61% of patients were men and 52.38% were women, the mean age was 62.89 years; predominant phototypes: II (44%) and III (43%); 6 cases (6.45%) of squamous cell carcinoma, 87 (93.54%) of basal cell carcinoma; 74.19% were primary tumors; the nose was the most frequent site (46.24%); a single surgical stage was performed in most cases, with flaps (44%) being the more frequently performed type of closure. There was recurrence in one patient, who required reoperation in October 2012 and followed without new recurrence. Conclusions: Mohs surgery has proven effective with high cure rates and a minimal recurrence rate, especially in lesions located in the face's H area of risk.

Keywords: MOHS SURGRY, CARCINOMA, BASAL CELL, CARCINOMA, SQUAMOUS CELL.

The Merkel cell carcinoma is a rare and highly aggressive neuroendocrine skin tumor. The purpose of this paper is to warn of the possibility of this diagnosis, usually not considered as an initial hypothesis in cutaneous neoplasias. The authors describe two cases of elderly female patients with complaints of a single erythematous nodule on the face. The diagnoses of basal cell carcinoma and amelanotic melanoma were considered. The presence of telangiectasias was evident at dermoscopy. The incisional biopsy's histology evidenced Merkel cell carcinomas. This neoplasia typically occurs in Caucasian patients with over 65 years of age, emerging as an erythematous-purplish nodule of rapid growth, with immunohistochemistry being essential for the diagnosis.

Keywords: SKIN NEOPLASMS; CARCINOMA, MERKEL CELL; NEUROENDOCRINE TUMORS; IMMUNOHISTOCHEMISTRY

The Merkel cell carcinoma is a rare tumor of neuroendocrine and epidermal origin and with poor prognosis. It is classically associated with immunosuppression, exposure to the sunlight and, more recently, with the polyomavirus. It is positive for epithelial and neuroendocrine markers. The combined expression of these markers confirms the diagnosis. Polyomavirus tumors have an unfavorable prognosis. The authors report a case of Merkel cell carcinoma with atypical immunophenotype (CK20 negative) and aggressive behavior. The present report is aimed at highlighting the importance of dermatologists having knowledge of different immunophenotypes that may be associated with the Merkel cell carcinoma.

Keywords: CARCINOMA, MERKEL CELL; IMMUNOHISTOCHEMISTRY; MERKEL CELL POLYOMAVIRUS

The cuniculatum carcinoma is a rare, slow-growth, local aggressive subtype of the squamous cell carcinoma, presented as a verrucous lesion with a low metastasis capacity. Its histopathology shows keratin-filled crypts, and its etiology is linked with HPV, especially 11 and 16 subtypes. The treatment of choice is surgical excision, followed by regular monitoring due to the high risk of local recurrence. We report a case of a woman with Cuniculatum carcinoma treated with surgery with perioperative frozen section procedure, graft, and good evolution.

Keywords: Carcinoma; Carcinoma, Squamous Cell; Foot

O queratoacantoma (QA), apesar de frequente na prática diária, é um tumor que gera questionamentos. O aspecto mais intrigante associa-se à sua posição no limite entre malignidade e benignidade. A abordagem do tumor, bem como sua classificação, é controversa. Na definição da conduta, é importante levar em conta o potencial de transformação para carcinoma espinocelular. Desse modo, a excisão cirúrgica é a terapia de escolha, sempre que possível. Algumas situações merecem atenção adicional, como a imunossupressão associada. Neste artigo, relatamos um caso de QA gigante em um paciente com síndrome da imunodeficiência adquirida tratado com cirurgia micrográfica de Mohs.

Keywords: Ceratoacantoma; Retalhos Cirúrgicos; Neoplasias Nasais; Neoplasias Cutâneas; Cirurgia de Mohs; Síndrome de Imunodeficiência Adquirida; HIV; Imunossupressão

Sarcomas são neoplasias mesenquimais malignas, raras, que acometem, principalmente, crianças e adolescentes. O rabdomiossarcoma, subtipo oriundo da musculatura esquelética, é condição incomum em adultos, acometendo sítios de localização não habitual, crescimento rápido e de difícil tratamento. Apresenta-se caso de adulto jovem com nodulação em lóbulo auricular esquerdo, cuja análise histopatológica e imuno-histoquímica confirmou tratar-se de rabdomiossarcoma alveolar, o qual foi conduzido em conjunto com a Oncologia.

Keywords: Rabdomiossarcoma Alveolar; Miogenina; Desmina; Excisão de Linfonodo

Merkel cell carcinoma is a rare and aggressive neuroendocrine skin tumor usually presenting as a single lesion in the head or neck region. We report a case of atypical topography and presentation, with multiple and simultaneous tumors on the left leg of rapid progression associated with palpable inguinal lymphadenopathy and diagnostic confirmation by histopathology and immunohistochemistry. Exeresis of the left inguinal lymph node and skin lesions with a safety margin was performed.

Keywords: Carcinoma Merkel cell; Merkel cells; Merkel cell polyomavirus

The preservation of the surgical margins marking is essential during Mohs micrographic surgery. However, skin degermation during antisepsis and the use of gauze during local anesthesia often remove these markings. The use of the protective film Cavilon^® 3M to fix the marking pen ink was effective in preserving the surgical map, allowing an accurate removal of the surgical specimen.

Keywords: Mohs surgery; Carcinoma, Basal cell; Carcinoma, Squamous cell; Excision Margins

Merkel cell carcinoma is a rare and aggressive cutaneous neuroendocrine cancer that occurs in the photodamaged skin of white and elderly patients, usually presenting as a solitary plaque or nodule in the head and neck region. When located in the lower palpebral area, reconstructing the defect resulting from its excision can become challenging for the dermatological surgeon due to the local cosmetic and functional peculiarity. We report the use of a bilobed flap for lower eyelid reconstruction with a satisfactory result, both in terms of aesthetics and the resulting functionality.

Keywords: Surgical flaps; Eyelids; Carcinoma, Merkel Cell; Case reports