Age / Sex : 57 / F

Chief complaint: right knee pain for 1 year

Tenosynovial giant cell tumor

Discussion

Findings:

1) T1WI

  a) Intermediate to hyperintense signal
intensity relative to skeletal muscle

2)
Fluid-sensitive sequences

  a) Heterogenous variable signal intensity
(relatively high signal intensity)

  b) Variable circular regions of low signal
intensity (hemosiderin)

      Cleft like high signal internal regions

  c) Small effusion may be present

3) Gradient
echo sequence:

  a)Small amounts of hemosiderin may
"bloom” which is
greater in PVNS

  than in nodular synovitis

4) Contrast
enhancement

 a) Heterogenous moderate to prominent
enhancement;

Diagnosis: Tenosynovial giant cell tumor

Discussion:

Terminology

1) Synonyms

      Synovial giant cell tumor

      Intraarticular giant cell tumor

      Localized nodular synovitis

 2)
Definitions

      Benign proliferative synovial tumor

Microscopic
pathology

  a) Proliferation of histiocytes
bearing lipids and with a variable number of multinuclear giant cells.
(Localized nodular synovitis of the knee and pigmented villonodular
synovitis(PVNS) are similar histologically)

Clinical Features

1) Clinical
presentation

   a) Clinical manifestations are nonspecific.

   b) The symptoms may include pain, swelling
or fullness, joint-line tenderness, restricted knee motion, and a palpable
mass.

2) Treatment

   : Surgical intervention is the best
therapeutic choice

  
(cf) PVNS : Synovectomy is required)

General
Features

1) Location

a) Localized
nodular synovitis most frequently involves tendon sheaths of fingers or toes
(giant cell tumor of the tendon sheath)

b) When
process is intraarticular, knee > ankle

 Infrapatellar (Hoffa) fat pad >
suprapatellar pouch > posterior intercondylar notch, adjacent to posterior
cruciate ligament

2) Size : 2-9 cm

3) Morphology: Ovoid or
lobulated

Differential
Diagnosis

1) PVNS

 a) Similar histological finding

 b) PVNS becomes more involved, the synovial
masses constrict the joint, whereas localized nodular synovitis tends to grow
outward, becoming pedunculated.

 c) Characteristic features of PVNS

     - Diffuse frond-like projections of
synovium

- Hemorrhagic joint effusion

- Deposits of hemosiderin (blooms on
gradient echo)

2)
Intraarticular Chondroma

  a) Located in Hoffa fat pad

  b) Lobulated Hyperintense SI cartilage on
fluid-sensitive sequence

3) Hoffa
Disease

  a) Inflammation and fibrosis within fat pad

  b) Ill-defined margin

4) Gout

  a) Areas of low signal on fluid-sensitive
sequences may be similar

  b) Intense enhancement

  c) Associated erosions if longstanding

References:

1. Manaster BJ et al: Diagnostic imaging musculoskeletal:
non-traumatic disease. 2^nd ed. Philadelphia Lippincott Willians
& Wilkins. 144-7, 2010

2. Yoo JH et al: Localized nodular synovitis of the knee
presenting as anterior knee pain: a case report. Knee. 14(5):398-401, 2007

3. Huang GS et al: Localized nodular synovitis of the knee:
MR imaging appearance and clinical correlates in 21 patients. AJR Am J
Roentgenol. 181(2):539-43, 2003