Unusual presentation of recurrent follicular lymphoma as diffuse granular shadow.

A 75-year-old man was diagnosed with advanced follicular lymphoma because of enlarged cervical lymph nodes. He received chemotherapy and was in complete remission for four years. However, after four years, he developed diffuse lymphadenopathy in the abdominal and iliac area suspected to be recurrent follicular lymphoma. At the time, he was asymptomatic and did not have any accompanying lung lesions. Due to his asymptomatic state, careful monitoring was chosen. Later, he developed diffuse granular shadow in the lung fields. A definite diagnosis was difficult to achieve without histological findings. Therefore, transbronchial lung biopsy of the lesions was performed. The pathology and immunohistochemistry of the lesions revealed recurrent follicular lymphoma. Although the frequency of recurrent follicular lymphoma presenting with diffuse granular shadow is uncommon, recurrent malignant lymphoma should be considered as a differential diagnosis in case with a history of malignant lymphoma.