In the reactive or pseudoepitheliomatous hyperplasia margins

In the reactive or pseudoepitheliomatous hyperplasia, margins of the proliferating epidermis are often pointed or irregular rather than bulbous, with a more marked inflammatory infiltrate than a mild-to-moderate one, which is associated with carcinoma cuniculatum. In addition, the presence of anaplastic nisoldipine suggests the diagnosis of cutaneous squamous cell carcinoma, and not carcinoma cuniculatum or verrucous carcinoma, even though the foci of conventional squamous cell carcinoma within a verrucous carcinoma deserve special recognition as a hybrid verrucous–squamous cell carcinoma. Therefore, histologic diagnosis can be difficult. A deep biopsy of the lesion is necessary to rule out other diagnoses. The standard treatments for carcinoma cuniculatum are surgical excision and the Mohs technique (serial excision for microscopic analysis), both of which are associated with a high cure rate and a low recurrence rate. Determination of the appropriate surgical margin in conventional surgical excision has often been an area of debate. By contrast, tissue sparing and complete margin control are two of the potential benefits of the Mohs surgery. When the lesion is on the vital structure or face, Mohs surgery may play a substantial role in preserving a functional or cosmetic outcome, as in the case of our patient. Alternative treatments include curettage and electrodesiccation, cryosurgery, alpha-interferon, systemic retinoids, chemotherapy using methotrexate, bleomycin or 5-fluoruracil, carbon-dioxide laser therapy, and radiotherapy. Controversy persists concerning irradiation in managing carcinoma cuniculatum. Despite reports describing the radiation-associated anaplastic transformation of the tumor (a risk factor of 10.7%), radiation therapy is frequently used in patients with extensive comorbidity that precludes surgery. Overall, the prognosis of carcinoma cuniculatum is usually favorable. Typically, the tumor remains indolent for several years, but it may extend into the subcutaneous tissue or metastasize. As the course is characterized to be slow but with continuous local growth, morbidity results from the destruction of local skin and soft tissue and rarely from perineural, muscle, or bone invasion. Painful nonmalignant lymphadenopathy can be observed with concurrent infection. The occurrence of distant metastases is rare, and therefore, mortality is mostly due to local invasion, rather than metastatic spread. Recurrence is also rare after complete treatment. To our knowledge, the present case, which involved carcinoma cuniculatum following keratoacanthoma at the nasal tip, is the first such report in the literature. An inadequate margin and chronic inflammation after initial resection may cause further malignant change. In addition, balancing an adequate resection margin with an optimal cosmetic outcome is difficult when the tumor is located at the nasal tip. Mohs surgery may play a substantial role when the tumor is located on the vital structure, as in the case of our patient. It may also result in a lower local recurrence rate. However, because of the time-consuming nature of the procedure, false negative rate, and shortage of experienced histotechnicians and pathologists, the patient refused Mohs surgery and chose excisional biopsy to first determine the nature of the tumor, followed by wide excision with 5-mm safe margins. After wide excision, reconstruction with full-thickness skin graft was performed smoothly in this patient. This process was undertaken to produce a lower complication rate and for easier detection of local recurrence. Reconstruction of the nasal tip is often a complex process because of limited nearby tissue reservoirs, highly contoured topography, and a conspicuous location. When reconstruction is approached empirically, an algorithm that is based on skin type, defect size, and location is useful to determine the most appropriate repair for a given patient. Local flaps, such as the bilobed and nasolabial flaps, have an excellent color and texture match with adjacent tissues but are suitable only for small nasal defects. Other drawbacks of local flaps include a dramatic ability to distort the symmetry of the distal nose and a high risk of pin cushioning if design is not planned appropriately. Defects that exceed 1.5 cm in diameter, especially those that involve the entire tip subunit, are most amenable to a regional flap or staged paramedian forehead flap repair. As the forehead skin is thicker than the nasal skin, thinning of the flap is required. Compared with local or regional flap reconstruction, full-thickness skin grafting has a lower complication rate, and yields easier detection of local recurrence but inferior coverage for cartilage exposure and worse appearance caused by color mismatch and contour defects.