Mononuclear pneumonia in sudden death or rapidly fatal illness in infants

Abstract

Summary In those infants older than 9 days who die unexpectedly, either in apparent good health or after a short period of severe illness, a diffuse mononuclear pneumonia is frequently found at autopsy. This is associated with less characteristic findings in other organs. Hyperplasia of lymphoid tissue occurs most commonly in the intestinal wall, in the mesenteric lymph nodes, and in the spleen, whereas the mediastinal lymph nodes are frequently not enlarged. The difficulties of judging the normal appearance of lymphoid tissue in infants are pointed out. Clinical and pathologic findings suggest infection as the cause of these changes, but bacteria are not regularly found. This, together with the appearance of the changes, as well as other considerations, suggest as one possibility a viral etiology; no proof of this is available. Whatever the cause of this disease, it is probably not fatal in many instances. However, the occurrence of the pathologic changes here described in cases of sudden death should be known in order that faulty diagnoses of accidental asphyxia or status thymicolymphaticus may be avoided, and also as a basis for future search for the cause of the disease.