SYP and small cell lung carcinoma: Clinical and radiographic screening to exclude metastasis from primary noncutaneous small cell carcinoma (e.g., SCLC) and other IHC stains for MCC (e.g., neurofilament, chromogranin A, synaptophysin, and Merkel cell polyomavirus large T antigen) can be obtained if the diagnosis remains in question [7, 10, 15, 17].