Lymphocyte-Rich Classical Hodgkin Lymphoma. A Case with Difficulty in Distinguishing from Nodular Lymphocyte-Predominant Hodgkin Lymphoma.

A 35-year-old man was referred to our hospital because of left supraclavicular and cervical lymphadenopathies. Histopathological examination of the lymph nodes revealed reactive lymphadenopathy. He visited our hospital three years after the initial diagnosis because of enlarged left cervical lymph nodes. Histopathologically, both Hodgkin/Reed-Sternberg (H/RS) and lymphocyte-predominant (LP) cells were found in the lymph node. We first suspected nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL), because these cells were CD15(-) and CD30(-). However, the diagnosis of lymphocyte-rich classical Hodgkin lymphoma (LRCHL) was finally confirmed, because these cells were found to be CD20(-), Bob.1(+), Oct.2(-), and BCL6(-) by additional immunostaining. The patient was treated with six cycles of ABVD chemotherapy, and a complete response was achieved. However, he underwent autologous stem-cell transplantation after high-dose chemotherapy owing to a relapse 10 months after primary treatment. Distingushing LRCHL from NLPHL was difficult in this patient, because histopathological examination showed both H/RS and LP cells, and immunostaining revealed these cells to be triple negative (CD15(-), CD30(-) and CD20(-)). Accumulation of such cases are necessary to establish better criteria for the differential diagnosis and assessment of clinical behavior.