Case Of the Week (COW) 13 March 2016
GAINT CELL TUMOUR
Findings:
X-ray : • Expansile third metacarpal lesion with significant endosteal scalloping and thinning of cortex. Lesion shows internal septa. • No break in the cortex noted. Periosteal reaction noted on the proximo lateral aspect of metacarpal. • No involvement noted in the MCP joint and carpometacarpal joint. MRI : Expansile lobulated T1 hyperintense to muscle and T2 hyperintense to fat noted in the third metacarpal with predominant shaft involvement with lesion extending upto the subcortical margin. Lesion doesn’t cross the joint. No evidence of fluid level. Lesion displacing the flexor tendon with no evidence of palmar plate disruption. Cortical break noted at the site of previously mention periosteal reaction.
Discussion:
The most common specific location of GCT is about the knee (50%–65%).The single most common site is the distal femur (23%–30%), followed by the proximal tibia (20%–25%), distal radius (10%–12%) ,sacrum (4%–9%), and proximal humerus (4%–8%). Other, less frequent sites of involvement include the proximal femur (4% of cases), innominate bone (3%), vertebral bodies (3%–6%), distal tibia (2%–5%), proximal fibula (3%–4%), hand and wrist (1%–5%), and foot (1%–2%). Lesions invariably demonstrate geographic bone lysis, most commonly associated with a narrow zone of transition and lacking surrounding sclerosis (80%–85% of cases) . Although the majority (42%–93%) of lesions are eccentrically located , lesions that are large at presentation more frequently appear central in location . Cortical thinning of bone is invariably apparent at radiography performed at clinical presentation. Expansile remodeling of bone is also frequently seen (47%–60% of cases). Cortical penetration is seen in 33%–50% of cases, often with an associated soft-tissue mass . Periosteal reaction is relatively unusual and is reported at radiography in 10%–30% of cases . Pathologic fracture, which may be complete or incomplete, is seen in 11%–37% of patients .At radiography, GCTs often demonstrate prominent trabeculation (33%–57% of cases) with a resultant multiloculated appearance . This appearance frequently represents pseudotrabeculation from osseous ridges created by endosteal scalloping. This pseudotrabeculation is often well demonstrated by comparing radiographic findings with CT findings .
GAINT CELL TUMOUR
Findings:
X-ray : • Expansile third metacarpal lesion with significant endosteal scalloping and thinning of cortex. Lesion shows internal septa. • No break in the cortex noted. Periosteal reaction noted on the proximo lateral aspect of metacarpal. • No involvement noted in the MCP joint and carpometacarpal joint. MRI : Expansile lobulated T1 hyperintense to muscle and T2 hyperintense to fat noted in the third metacarpal with predominant shaft involvement with lesion extending upto the subcortical margin. Lesion doesn’t cross the joint. No evidence of fluid level. Lesion displacing the flexor tendon with no evidence of palmar plate disruption. Cortical break noted at the site of previously mention periosteal reaction.
Discussion:
The most common specific location of GCT is about the knee (50%–65%).The single most common site is the distal femur (23%–30%), followed by the proximal tibia (20%–25%), distal radius (10%–12%) ,sacrum (4%–9%), and proximal humerus (4%–8%). Other, less frequent sites of involvement include the proximal femur (4% of cases), innominate bone (3%), vertebral bodies (3%–6%), distal tibia (2%–5%), proximal fibula (3%–4%), hand and wrist (1%–5%), and foot (1%–2%). Lesions invariably demonstrate geographic bone lysis, most commonly associated with a narrow zone of transition and lacking surrounding sclerosis (80%–85% of cases) . Although the majority (42%–93%) of lesions are eccentrically located , lesions that are large at presentation more frequently appear central in location . Cortical thinning of bone is invariably apparent at radiography performed at clinical presentation. Expansile remodeling of bone is also frequently seen (47%–60% of cases). Cortical penetration is seen in 33%–50% of cases, often with an associated soft-tissue mass . Periosteal reaction is relatively unusual and is reported at radiography in 10%–30% of cases . Pathologic fracture, which may be complete or incomplete, is seen in 11%–37% of patients .At radiography, GCTs often demonstrate prominent trabeculation (33%–57% of cases) with a resultant multiloculated appearance . This appearance frequently represents pseudotrabeculation from osseous ridges created by endosteal scalloping. This pseudotrabeculation is often well demonstrated by comparing radiographic findings with CT findings .