ABSTRACT
Merkel cell carcinoma (MCC) is a rare, cutaneous neuroendocrine malignancy with increasing incidence. The skin of the head and neck is a common subsite for MCC with distinctions in management from other anatomic areas. Given the rapid pace of developments regarding MCC pathogenesis (Merkel cell polyoma virus (MCPyV)-positive or virus-negative, cell of origin), diagnosis, staging and treatment, and up to date recommendations are critical for optimizing outcomes. This review aims to summarize currently available literature for MCC of the head and neck. The authors reviewed current literature, including international guidelines regarding MCC pathogenesis, epidemiology, diagnosis, staging, and treatment. Subsequently recommendations were derived including the importance of baseline imaging, MCPyV serology testing, primary site surgery, nodal evaluation, radiotherapy, and the increasing role of immune modulating agents in MCC. MCPyV serology testing is increasingly important with potential distinctions in treatment response and surveillance between virus-positive and virus-negative MCC. Surgical management continues to balance optimizing local control with minimal morbidity. Similarly, radiotherapy continues to have importance in the adjuvant, definitive, and palliative setting for MCC of the head and neck. Immunotherapy has changed the paradigm for advanced MCC, with increasing work focusing on optimizing outcomes for non-responders and high-risk patients, including those with immunosuppression.
ABSTRACT
Caudaequinatumors are histologically diverse. International Classification of Diseases for Oncology (ICD-O3) confers dedicated site code (C72. 1) for cauda equina. This code is excluded during analyses of other primary spinal cord tumors. In this retrospective study, the Surveillance, Epidemiology and End Results (SEER) data for primary cauda equina tumors (PCET, C72. 1) excluding the tumors of spinal meninges (C70. 1) from 1992 to 2015 were reviewed. Demographic characteristics, tumor types, and clinical outcomes were analyzed using univariable analysis. Overall survival was estimated using Kaplan-Meier methods and compared for age, histology and treatment type. 293 patients with PCET met inclusion criteria. The most common tumors comprised schwannoma (32%), myxopapillary ependymoma (21%), malignant ependymoma (22%). The median age at diagnosis was 50 years (range < 1 year to 98 years), 57% of patients were males. 77% of the patients underwent surgery. Median follow up time for these patients was 70 months. Of the 293 patients, 250 (85%) were living at the end of 2015. The cause of death was tumor or CNS related in 15 patients. 136 patients were followed for <5 years, of which 102 were censored and 34 died (11.6%) before 5 years. Using univariable analysis, age at diagnosis (Hazard Ratio, HR 1.05; confidence interval, CI 1.03-1.07; p < 0.001), malignant tumor type (HR 2.88, CI 1.15-7.19, p = 0.0239) and absence of surgical intervention (HR 2.54, CI1.26-5.11, p = 0.0092) were predictors of increased mortality. Although most patients did well, older age and lack of surgical intervention were associated with worse survival.