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A 71-year-old male golf enthusiast presented with new-onset weight loss and rapidly-growing plaque-like masses involving the left arm. A complete blood count with differential was essentially unremarkable. A biopsy of the plaque-like mass exhibited similar findings to this micrograph, with sheets and nodules of highly atypical basophilic cells with scant cytoplasm, large nuclei with granular chromatin, and indistinct nucleoli, with apoptotic bodies and occasional mitotic figures. Immunohistochemical studies for CD45 (LCA), CD20, CD3, MPO, CK AE1/AE3, and S100 were performed. The tumor cells were negative for CD45, CD20, CD3, MPO, and S100, and were positive for CK AE1/AE3. Further staining demonstrated the cells to be positive for CK20 (perinuclear dot-like pattern) and synaptophysin, consistent with Merkel cell carcinoma. Notably, the tumor was also positive for PAX-5, which may be a diagnostic pitfall in the diagnosis of Merkel cell carcinoma (approximately 90% of Merkel cell carcinomas can express PAX-5, see Kolhe et al Int J Clin Exp Pathol 2013;6). These cases may also bear resemblance to B-lymphoblastic leukemia, which presents another diagnostic consideration and possible pitfall. The patient underwent aggressive complete wide local excision with adjuvant radiation, complicated by recurrence (including distant metastases) 14 months after surgery, and he expired shortly thereafter.