Pathologic Quiz Case 1
Robert J. Weil, MD, Chicago, IllAn 82-year-old man noted a small, firm nodule over the left temporal region 6 months prior to initial presentation. It was elevated, smooth, and nontender and measured 1 mm2. An initial excisional biopsy specimen was interpreted as a poorly differentiated squamous cell carcinoma. Immunohistochemical studies were reported to show staining for epithelial membrane antigen and cytokeratin; they were negative for leukocyte common antigen and neuron-specific enolase.The patient was referred for treatment. At the time of resection, metastatic disease was found in numerous ipsilateral lymph nodes and in the parotid gland. A neck dissection and parotidectomy were performed in conjunction with wide excision of the primary site. Representative sections from the skin and parotid gland are shown in Figs 1 through 3. Immunohistochemical stains were positive for neuron-specific enolase; cytokeratin stained in a paranuclear pattern. Electron microscopy (Fig