[Intramuscular vascular malformations as a differential diagnosis of focal myositis].
BACKGROUND
Focal myositis constitutes an original and rare pathological entity, characterized by a localized inflammation within skeletal muscle, presenting as a soft tissue painful tumefaction. Diagnosis requires histological confirmation because of its non-specific clinical feature and the numerous differential diagnoses.


METHODS
We report a 27 year-old man who presented with suggestive symptoms of focal myositis. MR imaging and echography were compatible with this diagnosis but also demonstrated the existence of a vascular component within the tumefaction. The diagnosis of a benign vascular malformation with intramuscular development was made by a surgically guided biopsy.


CONCLUSIONS
Vascular malformations are histologically heterogeneous with extremely variable clinical expressions. When they develop within skeletal muscle, they may mimic focal myositis. Hence, their diagnosis has to be evoked before performing muscle biopsy, because of the potential hemorrhagic risk.
Froissart
A
A
Service de médecine interne I, groupe hospitalier Pitié-Salpêtrière, 47-83, boulevard de l'Hôpital, 75651 Paris cedex 13, France.
Pagnoux
C
C
Koskas
F
F
Dubourg
O
O
Chérin
P
P
D000328:Adult; D001706:Biopsy; D001808:Blood Vessels / Q000002:abnormalities* / Q000473:pathology; D003937:Diagnosis, Differential; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000473:pathology; D009220:Myositis / Q000175:diagnosis*