This is a protocol for a Cochrane Review (Diagnostic test accuracy). The objectives are as follows: To determine the diagnostic accuracy of sentinel lymph node biopsy (SLNB) for the detection of nodal metastases (in the investigated nodal basin) for the staging of cutaneous squamous cell cancer (cSCC). To determine the diagnostic accuracy of imaging tests, including ultrasound, computed tomography, magnetic resonance imaging and positron emission tomography, alone or in combination, for the detection of any metastasis for the staging of cutaneous squamous cell cancer. To determine the diagnostic accuracy of imaging tests for the detection of nodal metastases in the staging of cutaneous squamous cell cancer. To determine the diagnostic accuracy of imaging tests for the detection of distant metastases in the staging of cutaneous squamous cell cancer. We will estimate these separately for those undergoing primary staging and those who have experienced a disease recurrence. Sources of heterogeneity We will consider a range of potential sources of heterogeneity for investigation in each individual test review. These may vary between reviews but may include the following. i. Population characteristics • Primary tumour site (head and neck, trunk, limb, and other) • Primary staging versus mixed or unclear populations (i.e. including staging of recurrent disease) 1 Tests to assist in the staging of cutaneous squamous cell carcinoma: a generic protocol (Protocol)