Alterations of the thymus and peripheral lymphoid tissues in fatal measles. A review of 14 autopsy cases.

As a result of re-examining 14 autopsy cases of fatal measles, neither aplastic nor hypoplastic thymuses were found even in a case with giant cell pneumonia, but there were degenerative and/or necrotic changes with giant cells mostly in the thymus and less in the peripheral lymphoid organs such as spleen, lymph nodes, Peyer's patches and tonsils. This damage of the lymphoid system was associated with the occurrence of complications, particularly of giant cell pneumonia and encephalitis. The lymphoid cell damage, which might be primarily due to virulence of the infected measles virus, seemed to prolong the viremia. Involvement of viremia in the process of complication is discussed.