A 45-year-old man presented with a 3-month history of blood-tinged sputum in the morning. Physical examination revealed a red granular tumor in the nasopharynx that filled the right side of the pharyngeal recess (Rosenmüller fossa) and bled easily when touched. Magnetic resonance imaging revealed a mass in the nasopharynx (Figure 1) and a retropharyngeal lymph node. Representative hematoxylin-eosin–stained sections of the nasopharyngeal tumor showed an intact mucosa lining, with many large, blue, round cells in the submucosa. The cells contained prominent large eccentric nuclei with a clockwise arrangement of the chromatin and abundant basophilic cytoplasm (Figure 2). Immunohistochemical staining demonstrated that the cytoplasm of the cells was strongly positive for common leukocyte antigen and immunoglobulin κ light chain (Figure 3) but negative for λ light chain (Figure 4). The complete blood cell count and the serum levels of calcium, creatinine, and uric acid were within normal limits. Electrophoresis of serumand urine specimens did not reveal any monoclonal paraprotein, and a bone survey showed no osteolytic lesion. The findings of a bone marrow biopsy were unremarkable.
Liao L, Chang Y, Ting L, Wang C. Pathology Quiz Case 2. Arch Otolaryngol Head Neck Surg. 2006;132(11):1269. doi:10.1001/archotol.132.11.1269