Case

• M/23• C.C. : 1st MTP joint pain (1YA)

20070210 Foot AP/ sesamoid

20061202 Outside CT (Rt. Foot)

Radiologic findings-CT

• Expansile osteolytic mass at medial sesamoid of hallux

- with suspicious fracture lines -> DDx) 1. chondroblastoma or GCT 2. ABC 3. intraosseous gout

• Rec) Rt foot MRI using microcoil

20070220 Foot MRI (Rt.)_Contrast

T1 sagittal

T1 sagittal (FS/Gd+)

T1 coronal

20070220 Foot MRI (Rt.)_Contrast

T1 axial T2 axial

T1 axial (FS/Gd+)

Radiologic findings-MRI

• Expansile mass involving medial sesamoid of hallux- peripheral irregular thick enhancement and central nonenhancin

g cystic or necrotic area- with its associated synovial enhancement of lst MTP joint- with bony erosion at lst metatarsal neck c reactive bone marrow

edema- vascular structures anterior to the mass- closely abutting flexor hallucis tendon

->DDx) 1. intraosseous gout,most likely 2. tbc 3. tumorous condition such as giant cell tumor or chondroblastoma

Hospital course

• Op: Excision of Sesamoid, Rt.(2007-02-26)

• Pathologic diagnosis– Soft tissue, right foot, excision

• 1. Numerous rhomboid crystals showing birefringence• 2. Some foci of calcium deposit • 3. Chronic granulomatous inflammation

with 1) multinucleated giant cells 2) central hyaline degeneration

consistent with calcium pyrophosphate dihydrate deposition disease

Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease

• Etiology– Idiopathic: most common

• Increased with age (7% of population near age 70 and 30-60% by the age 80)– Hereditary: autosomal dominant condition

• Maybe associated with ANK(chromosome 5p15)– Secondary: 5-10% of patients have metabolic disease.

• Hyperparathyroidism, Hemochromatosis, Hypophosphatasia…

• Clinical patterns– Asymptomatic chondrocalcinosis– CPPD crystal arthropathy

• Pseudogout (18%), pseudo-osteoarthritis with/without synovitis (40%/18%), pseudorheumatoid arthritis (8%)

• Common location: Knee, wrist, MCP joint

Seminars in musculoskeletal radiology 2003;07:175-186

Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease

• Diagnositic imagings– Conventional radiography

• Calcification within or around joints– Chondrocalcinosis – Synovial and capsular calcifications– Other soft tissue calcification

• Findings of pyrophosphate arthropathy– Bilateral, symmetrical involvement of affected articulations– Cartilage loss, subchondral plate sclerosis, subchondral cyst formation– Subchondral collpase, fragmentation, intra-articular loose body

– MRI• Less dense calcium deposition->GRE sequence is more sensitive than c

onventional radiography.

Seminars in musculoskeletal radiology 2003;07:175-186

Seminars in musculoskeletal radiology 2003;07:175-186