Eur Radiol (2004) 14:2151 DOI 10.1007/s00330-004-2346-9

I N T E R P R E TAT I O N C O R N E R

© Springer-Verlag 2004

A pediatric upper limb mass (2004:11a) Case report A 12-year-old female patient was admitted to our hospital for the investigation of a mass in the left forearm. The mass was already present when she was 2 years old, but it had gradually increased in size over the last 2 years. The patient was referred because of episodes of pain and swelling approximately once a month, lasting from a few days to a week, after which spontaneous improvement occurred. Clinically, the mass was soft and not adherent to the skin; palpation was painful. Ultrasound (US) of the left upper arm was performed by a 10-Mhz transducer. US clearly demonstrated a multi-locular cystic mass, extending to the distal third of the forearm, containing septa of variable thickness and localized highdensity fluid content. MRI was performed in the axial, sagittal and coronal planes, and depicted a multilocular cystic mass, localized in the prefascial subcutaneous tissue with intermediate to high signal intensity on TI-weighted sequences and multiple hyperintense areas on T2-weighted sequences.

brief summary. The summary will describe exactly how the case was investigated at the host institution, how the diagnosis was established and the teaching points of the case in question. The names of the first 25 radiologists submitting the correct diagnosis will be published (only one from any individual center and none from the host institution)!

What is your diagnosis? How can it be confirmed? Readers are invited to supply one possible diagnosis via electronic means to [email protected] stating ‘Interpretation Corner 2004:11a’ in the subject/title of their email. You should include your name, title, address, fax and phone number. The deadline is one clear calendar month from the distribution date. Three months after the initial publication of the case history, the authors will publish the final diagnosis and a

Fig. 1 US. Axial image on the left forearm. US demonstrates a multilobulated lesion, which consists of anechoic fluid (arrows) with thin septae inside (arrowheads) alongside a hypoechoic component (*)

Fig. 2 a–b MRI of the left forearm. Axial T1-weighted unenhanced SE images (TR: 500, TE: 16 ms) show a lesion with two components: a slightly hyperintense mass (*) with thin hypointense septae and a cranial highly hyperintense mass (arrow). b Axial T2-weighted SE image (TR: 3,500, TE effective: 130) shows homogeneous high signal intensity of the whole mass, while the septae remain hypointense (arrowheads)