[Non-traumatic myositis ossificans circumscripta in the teres major muscle].
A 49-year-old male presented with a painful progressive swelling in his right axillar region, without further complaints, which had been present for 2 weeks. On radiological examination a peripheral circumferential zone of mineralisation was seen in the right teres major muscle. An incision biopsy specimen showed a lesion of fibroblastic tissue in which areas of osteoid and fragmented lamellar bone tissue, without signs of malignancy. The diagnosis was myositis ossificans circumscripta. This is a rare benign ossifying lesion in skeletal muscles, mostly caused by a trauma and with an average age of occurrence between 20 and 30 years old. It must be differentiated from extra-skeletal osteosarcoma. The pathogenesis is unknown. Because it is a benign and self-limiting disorder, surgical excision is only necessary in case of mechanical hindrance. The patient's swelling partially regressed and he had no further complaints.
Arends
J E
JE
Afd. Inwendige Geneeskunde, Onze Lieve Vrouwe Gasthuis, 1e Oosterparkstraat 279, 1090 HM Amsterdam. j.e.arends@olvg.nl
Drillenburg
P
P
van der Woude
H J
HJ
Roozendaal
K J
KJ
de Valk
B
B
D001365:Axilla; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D008875:Middle Aged; D019042:Muscle Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000473:pathology; D009221:Myositis Ossificans / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D012516:Osteosarcoma / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology