Squamous metaplasia of the upper portion of the sweat ducts has been observed in four patients who received chemotherapy; two patients with acute myelogenous leukemia, one patient with testicular carcinoma, and one patient with anaplastic carcinoma of the lung. This change is different (but perhaps related) from what is described in neutrophilic eccrine hidradenitis in patients with acute myelogenous leukemia and other tumors after chemotherapy. Syringosquamous metaplasia may be confused with well differentiated squamous cell carcinoma histologically.