Age / Sex : 52 / F

Chief complaint: Soft tissue mass at left palm since 1 year ago

1) What is your impression?

Two weeks later, you can see the final diagnosis with a brief discussion of this case.

(Quiz는 quiz일 뿐이오니 답안은 한개만 보내주시기 바라오며, 복수의 답안을 보내주시는 분은 정답이 포함되어 있더라도 부득이 semi-correct answer로 처리토록 하겠습니다.)

Courtesy: 정혜원(Hye Won Chung),

Juxtacortical (periosteal) chondroma, MC bone

Discussion

Findings:

 Radiograph of hand: Soft tissue bulging contour with matrix calcification surrounding left 2nd metacarpal head and neck.

 MR with enhancement: Soft tissue mass is noted around the head and neck of 2^nd MC bone near MCP joint showing high signal intensity on T2 WI and peripheral rim-like and nodular enhancement pattern suggesting cartilage tumor. Multiple small bone extrinsic erosion and focal marrow edema are associated with this mass at the metacarpal head and neck.

Flexor and extensor digitorum tendons and volar plate are displaced around the MCP joint by the mass.

Also, the mass shows bulging contour to the MCP joint area causing small bone erosion at dorsal base of proximal phalanx.

Differential Diagnosis:

Synovial osteochondromatosis in 2nd MCP joint

Chondroid tumor such as juxtacortical chondroma

Diagnosis: Juxtacortical (periosteal) chondroma, 2^nd MC bone

Discussion:

Chondroid tumor arising in periosteal layer of tubular bones.

Location: Metaphyseal, arising on surface of bone

Proximal humerus and femur (70%)

Phalanges (25%) (hands > feet)

MR images:

Soft tissue mass at the bone surface with pressure erosion of adjacent cortical bone

Lobulated configuration

No edema of medullary bone or soft tissues

Hypo- or isointense relative to muscle on T1-WI

Hyperintense relative to muscle on T2-WI

Peripheral contrast enhancement

Calcifications of the tumor matrix (50%) caused focal signal loss on MR images

Typically contained fibrovascular bundles, surrounding the cartilage lobules

References:

1.     Woertler K, Blasius S, Brinkschmidt C, Hillmann A, Link TM, Heindel W. Periosteal Chondroma: MR Characteristics. J Comput Assist Tomogr, 2001;25: 425-430.

2.     Resnick D, Kyriakos M, Greenway GD. Tumors and tumor-like lesions of bone: imaging and pathology of specific lesions. In: Resnick D, ed. Diagnosis of Bone and Joint Disorders. 3rd ed. Philadelphia: Saunders, 1995:3707–11.