Received: 16 May 2002 Revised: 17 July 2002 Accepted: 30 July 2002 Published online: 2 October 2002 © Springer-Verlag 2002 Abstract Our objective was to de- scribe the imaging features of lym- phadenopathy at the medial epitroch- lear region as frequently seen in cat- scratch disease (CSD) and to com- pare these features with those seen in non-CSD. Ten patients (four males and six females) presented with a subcutaneous soft tissue mass at the medial epitrochlear region. Three pa- tients were younger than 15 years. Magnetic resonance imaging was performed in all patients. All lesions turned out to be regional lymphaden- opathy instead of soft tissue neo- plasm. They were caused by benign disorders in eight cases, including seven CSD and one other infection, and in two cases by metastatic dis- ease. All lesions, except for three be- nign ones, were solitary. On MRI, high signal intensity (SI) strands in the surrounding soft tissue on T2- weighted images (WI) were present in all cases. Three cases of CSD showed homogeneous SI on both T1- and T2WI. After contrast admin- istration, a moderate, homogeneous enhancement was seen. The other seven lesions, except for one metas- tasis, had both solid and liquid com- ponents. Liquid components showed high SI on T2WI without enhance- ment, whereas solid components had intermediate SI on T2WI and marked enhancement after contrast administration. Pathological findings in seven patients, including four with CSD, supported the tentative diagno- sis made on MRI. One of two pa- tients with CSD had positive sero- logical test. Cat-scratch disease is a major cause of a soft tissue swelling at the medial epitrochlear region. Identification of lymphadenopathy and its presentation on MRI may be helpful in eliciting an animal-scratch history and achieving diagnostic and therapeutic aims in patients without primary cancer. Keywords Soft tissue mass · Lymphadenopathy · Cat-scratch disease · Epitrochlear lymph nodes · Magnetic resonance Eur Radiol (2003) 13:1363–1369 DOI 10.1007/s00330-002-1673-y MUSCULOSKELETAL J. Gielen X. L. Wang F. Vanhoenacker H. De Schepper L. De Beuckeleer J. Vandevenne A. De Schepper Lymphadenopathy at the medial epitrochlear region in cat-scratch disease Introduction Regional lymphadenopathy can be categorized into be- nign and malignant forms. The latter ones occur in pa- tients with primary malignancy or diseases of the lym- phatic system, whereas the former ones are caused by in- fection or inflammation. Cat-scratch disease is a com- mon cause of benign regional lymphadenopathy, espe- cially at the medial epitrochlear region, and is related to the high frequency of scratches on the hands [1]. The disorder is caused by B. henselae, a gram-negative bacte- rium [2]. The diagnosis may be rendered on the basis of clinical grounds in most cases and as a consequence ra- diological documentation of this disease is scarce but un- usual clinical manifestations may occur in 5–11% of pa- tients [3, 4]. Although a characteristic history in patients having lymphadenopathy, i.e., a scratch by a cat, may highly suggest the diagnosis, sometimes it cannot be J. Gielen · X.L. Wang · F. Vanhoenacker H. De Schepper · H. De Schepper A. De Schepper ( ✉ ) Department of Radiology, University Hospital Antwerp, Wilrijkstraat 10, 2650 Edegem, Belgium e-mail: Arthur.De.Schepper@uza.uia.ac.be Tel.: +32-3-8213506 Fax: +32-3-8252026 L. De Beuckeleer Department of Radiology, AZ St. Augustinus, Oosterveldlaan 24, 2610 Wilrijk, Belgium J. Vandevenne Department of Radiology, ZOL Campus St. Jan, Schiepse bos 2, 3600 Genk, Belgium