Management of Non-melanoma Skin Cancers: Rare Subtypes

Abstract

Several rare types of non-melanoma skin cancer exist that each present unique challenges in terms of diagnosis and management. Merkel cell carcinoma is a neuroendocrine skin cancer that is typically found on the head and neck region of older Caucasian males. It typically presents as an asymptomatic, rapidly growing red-violet nodule. Due to its aggressive nature, surgical excision with wide margins or Mohs surgery, often with adjuvant radiation, is recommended therapy. Pembrolizumab is a newer therapy for advanced Merkel cell carcinoma that has shown great promise. Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive and rarely metastatic sarcoma with extensive subclinical spread, necessitating large excision margins or Mohs surgery for treatment. Imatinib has been shown to be effective in a specific subset of advanced DFSP lesions. Atypical fibroxanthoma (AFX) is an intermediate-grade, superficial fibrohistiocytic neoplasm that typically presents on the head and neck of elderly Caucasian males. Newer guidelines have separated AFX and undifferentiated pleomorphic sarcoma (UPS) into two separate lesions. Treatment for AFX is primarily surgical via wide local excision or Mohs micrographic surgery. Sebaceous carcinoma is a rare and aggressive malignancy that is separated into periorbital and extraocular subtypes. Sebaceous carcinoma is primarily treated with wide local excision or Mohs surgery. Sentinel lymph node biopsy is recommended for periorbital sebaceous carcinoma, but not typically for extraocular sebaceous carcinoma. Dermatologists play a critical role in the diagnosis and treatment of all of these tumors, often in conjunction with a multispecialty team for comprehensive management.