Pathological involvement of human gastrocnemius muscle in leptospirosis (a study in 63 patients)

The authors discuss the microscopic changes in gastrocnemius muscle in Leptospirosis in 63 patients. The hyaline necrosis frequently associated to a hemorrhagic infiltrate represented the most important feature in the lesional picture of the disease. Other findings were swelling, loss of cross striations, vacuolation and regenerative changes of muscle fibres. This last one was represented by multinucleated sarcoblasts and the presence of thin and strongly basophilic new-formed fibres. Interstitial hemorrhage was frequently seen and an inflammatory afflux was only rarely observed. This histological picture was considered as characteristic and highly significant for the diagnosis of Leptospirosis.