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Age / Sex : 72 / M
Chief complaint : painless swelling of left lower leg
What is your impression?
Two weeks later, you can see the final diagnosis with a brief discussion of this case. (Please submit only one answer)
Courtesy: Seon-Jeong Kim, Myongji Hospital
Diagnosis: Calcific myonecrosis
Discussion
Findings:
Large,
well-defined fusiform mass with irregular thick,
shell-like and lobular calcification involving
anterior and lateral muscle compartments of lower leg
Heterogeneous
isointense SI with multifocal irregular areas of dark SI on T1WI
Diffuse dark
SI with small focal round area of high SI on T2WI, STIR image
Dark SI rim
Focal
irregular area of dark SI in the deep posterior compartment
No
enhancement
Differential Diagnosis:
Calcified
soft-tissue mass: hematoma,
synovial sarcoma, epithelioid sarcoma, soft-tissue osteosarcoma, parosteal
osteosarcoma
Calcification
in soft tissue: myositis
ossificans, posttraumatic pseudoaneurysms, dermatomyositis/polymyositis,
tumoral calcinosis, diabetic myonecrosis
Diagnosis:
Calcific
myonecrosis
Discussion:
Calcific
myonecrosis occurs as a late sequel to compartment syndrome or injury to
peroneal nerve.
Most likely
result from posttraumatic ischemia and cystic degeneration of the muscle.
Slow-growing,
usually painless mass in a previously injured limb (almost in the lower
extremity).
Radiograph, CT:
- fusiform mass with peripherally oriented plaquelike amorphous
calcifications within the entire muscle or compartment
- calcifications
are usually linear in orientation and sheetlike
- smooth
bony erosion, reactive periosteitis
MRI :
- variable, heterogeneous
SI
- intermediate
SI, high SI (subacute hemorrhage, proteinaceous content) on T1WI
- high SI (cystic change), low SI
(calcium salts, paramagnetic breakdown products of hemorrhage) on T2WI
- low SI
outer rim (calcification and fibrosis)
- no
enhancement
Treatment :
-biopsy
should be avoided (high risk of secondary infection and chronic fistula
formation)
-conservative
management
-complete
surgical excision and flap coverage
References:
O’Dwyer HM,
Al-Nakshabandi NA, Al-Muzahmi K, et al. Calcific myonecrosis: keys to
recognition and manangement, AJR Am J Roentgenol 2006;187(1):W67-76
Dhillon M,
Davies AM, Benham J, Evans N, Mangham DC, Grimer RJ. Calcific myonecrosis: a
report of ten new cases with an emphasis on MR imaging. Eur Radiol 2004;
14:1974-1979
Holobinko
JN, Damron TA, Scerpella PR, Hojnowski L. Calcific myonecrosis: keys to early
recognition Skeletal Radiol. 2003 Jan;32(1):35-40
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