["Bone tumor" diagnostic error in stress fracture of the medial tibial plateau].

Stress fractures occur in 13.2-37.0% in running athletes. There is a decreasing incidence of these fractures in the tibia (33%), navicular (20%), metatarsus (20%), femur (11%), fibula (7%) and pelvis (7%). Clinically stress fractures present themselves with uncharacteristic local pain under weightbearing conditions. In 75% the medial tibial crest is involved. Usually the pain disappears when the patient is non-weightbearing. As causal factors wrong training methods, oligomenorrhoe (6x incidence), low nutrition input (8x incidence) and a genu recurvatum-morphotype can be found. Misinterpretation can result from a similar clinical and radiological (conventional x-ray, scintigraphy, MRI) early course in stress fractures and bone tumors. We present a patient with a clinical diagnosis of a meniscus lesion. The following MRI was suspect for a malignant lymphoma or histiocytoma. Biopsy was performed and showed the final diagnosis of a stress fracture.