Recurrent cervical lymphadenopathy due to Ki-1 lymphoma in an elderly female

A 70-year-old female presented with recurring cervical lymphadenopathy over a 5-year period. Intermittently, symptoms of respiratory and GI tract disease occurred, raising the possibility of malignancy. Investigation of these systems and of the breasts were negative. A lymph node biopsy was eventually done and showed intrasinusoidal proliferations of CD30-positive malignant cells which were also characterized ultrastructurally. Therapy with CHOP has produced a good initial response. The value of electron microscopy in diagnostic pathology is illustrated.