IMAGES IN PEDIATRICS
A lump in an arm
Federica Pederiva & Edoardo Guida &
Giulio Andrea Zanazzo & Massimo Gregori &
Received: 11 July 2013 /Accepted: 18 July 2013
#Springer-Verlag Berlin Heidelberg 2013
Abstract The authors present a magnetic resonance image
showing a soft tissue mass misdiagnosed as sarcoma.
A 12-year-old boy presented with a painless, rapidly growing
swelling mass in his right arm without any other accompany-
ing symptoms or history of trauma. A 4×2-cm solid fixed
mass with normal overlying skin was palpated. Laboratory
tests and tumor markers were unremarkable.
Magnetic resonance imaging showed an enhancing mass
inside the triceps brachii muscle reached by two vessels
(Fig. 1). Excisional biopsy was performed and histopathology
revealed nodular fasciitis.
Nodular fasciitis is a benign reactive fibroblastic and
myofibroblastic proliferation most commonly diagnosed in
adults. Ten percent of the lesions occur in children especially in
the extremities or trunk and also in the head and neck. It is
usually subcutaneous in distribution but sometimes also in intra-
muscular and intermuscular locations involving skeletal muscle.
Theetiologyisstillunknownandwhetherthe reactiveprocess is
triggered by local injury or inflammatory processes is not re-
solved. It often develops rapidly, which may be concerning for
malignancy, being the most common benign mesenchymal le-
sion misdiagnosed as sarcoma. Spontaneous regression is the
natural history and a proper diagnosis is essential to avoid
unnecessarily aggressive treatment [1–3]. Although relatively
rare, nodular fasciitis should be considered in the differential
diagnosis in any pediatric patient with a soft tissue mass.
Conflict of interest
conflict of interest, real or perceived.
There is no financial assistance or any potential
1. Hutter RV, Stewart FW, Foote FW Jr (1962) Fasciitis. A report of 70
cases with follow-up proving the benignity of the lesion. Cancer
2. Tomita S, Thompson K, Carver T, Vazquez WD (2009) Nodular
fasciitis: a sarcomatous impersonator. J Pediatr Surg 44:e17–e19
3. Weinreb I, Shaw AJ, Perez-Ordonez B, Goldblum JR, Rubin BP
(2009) Nodular fasciitis of the head and neck region: a clinicopatho-
logic description in a series of 30 cases. J Cutan Pathol 36:1168–1173
Fig. 1 Axial enhanced MRI of the right arm showing a hyperintense
well-circumscribed mass inside the triceps brachii muscle. Two vessels
reach the nodule
F. Pederiva (*):E. Guida:G. A. Zanazzo:M. Gregori:J. Schleef
Institute for Maternal and Child Health - IRCCS “Burlo Garofolo”,
Via dell’Istria 65/1, 34137 Trieste, Italy
Eur J Pediatr