Post-therapy CT-detected mass in lymphoma patients: is it viable tissue?

The demonstration by computed tomography (CT) of enlarged nodes and/or masses in lymphoma patients has been interpreted as indicating that active disease is present. Four cases are presented in which either biopsy or laparotomy of a CT-detected mass after therapy revealed fibrous tissue with no evidence of viable neoplasm. These four cases demonstrate the possible pitfall of diagnosing viable lymphoma in masses detected by CT after therapy.