Atypical hyperplasia of lymph nodes: a follow-up study.

Atypical hyperplasia of lymph nodes (AH) is neither a clinical nor a pathologic entity but represents cases in which the pathologist expresses concern about neoplasia and is unable to diagnose lymphoma. We reviewed 70 cases of AH diagnosed over the years 1961-1972. Thirty-seven percent developed a malignant lymphoproliferative disease during a follow-up that varied from 2-13 years. When the cases were histologically reexamined without knowledge of their clinical outcome or initial clinical features, 19 were diagnosed as benign, 10 as malignant, 37 as AH, and 4 as angioimmunoblastic lymphadenopathy. None of the patients of the first group developed a malignant lymphoma, but lymphoma occurred in 30% of the AH group. This latter group was divided into two subgroups according to the expectation of the course of disease; those with a probably malignant course and those with a probably benign course. Malignant lymphoma developed in 8 (73%) of the 11 patients in the first group but in only 14% of the 26 patients in the second group. It appears that although the pathologist can rather well appreciate the probable development of malignant lymphoma in AH cases, he is wrong too often--in this series 16%. Therefore, the common practice of designating a suspicious lymph node biopsy as atypical hyperplasia with a request for a later repeat biopsy is recommended.