What does the presence of keratin positive cells in a lymph node biopsy suggest regarding the patient's diagnosis?

• A. Non-Hodgkin lymphoma
• B. Hodgkin lymphoma
• C. Squamous cell carcinoma
• D. Nasopharyngeal carcinoma

Answer: (D)

The presence of keratin positive cells in a lymph node biopsy is indicative of squamous differentiation, which aligns with the characteristics of certain malignancies. When keratin positivity is identified, it often suggests the presence of squamous cell carcinoma or tumors with squamous differentiation, such as nasopharyngeal carcinoma.

In the context of nasopharyngeal carcinoma, it is known that this type of cancer arises from the epithelium of the nasopharynx and can show keratin production. This means that keratin positive cells found in the lymph node could point to metastatic squamous cell carcinoma originating from the nasopharyngeal area. The confirmation of nasopharyngeal carcinoma would typically involve further clinical correlation, including possible imaging and additional histopathological studies, but the presence of keratin positivity remains a significant clue in establishing this diagnosis.

Therefore, the link between keratin positive cells and nasopharyngeal carcinoma is why this choice is appropriate given the context of the question.