Giant Cell Tumor

• Skeletally mature! Closed physis
• L: Distal radius, Epiphyseal, ecentric
• A: Lytic and expansile "Abutting joint surface" (crosses physis unlike ABC)
• R: Thinning of cortices, narrow zone, no periosteal reaction
• M: NA

• Physis closed - mature bone
• Lesion must be epiphyseal and abut the articular surface
• Lesion is eccentric
• Lesion is well defined

• Most common around the knee (Distal femur>proximal tibia)
• Distal radius
• Sacral Ala
• Spine (Vertebral body) [as opposed to ABC and OB which ocurs in posterior elements!]

• CXR/ CT Thorax - mets to lung in 2%
• MRI with contrast - May have fluid fluid levels.
• CT scan - to evaluate for zone of transtion, joint involvement
• 20% may have ABC component.

• 3 kinds of cells in GCT
• Type 1 (stromal mononuclear), Type 2 (precursor to giant cells) Type 3 (mutlinuclear giant cell)
• Proliferation of multinucleated stromal cells producing Rank-L and activating osteoclasts
• Like large omelettes

• Campanacci Classification

• 1 = Well defined margin
• 2 = Cortex thinned and expanded [but still present]
• 3 = Aggressive

• Currettage ➔ Adjuvant ➔ Fill
• Depends on intraosseous (campannaci 1,2) or extraosseous (campannaci 3) or expendable bones

• "Extended curettage" with Methylene Blue to guide, and HIGH SPEED BURR via a CORTICAL WINDOW, Adjuvant therapy, fill bone gap with PMMA KIV STABILIZATION
• Options for adjuvant - Phenol or liquid nitrogen or Argon Plasma Coagulator , 100% ethanol
• Mechanical - high speed burr
• Thermal - PMMA, cryotherapy, ABC, plasma beam
• Chemical - Phenol, ethanol, hydrogen peroxide

• The addition of adjuvant therapy of either phenol or liquid nitrogen has been found to reduce recurrence by a local paper by Dr Tan Munn Hong of SGH

• KIV stabilize

• lester SOA - frozen hexodane

• patients with G6PD positive as it may cause hemolysis in these patients.

• Actually it is slow process
• Means it is an active lesion but then enough time.

• In-vitro study published in JBJS found 95% ethanol, 5% phenol, 3% H2O2 and 50% Zinc Chloride showed significant reduction in DNA content and metabolic activity, sustained for up to 120 hours compared to water.

GCT adjuvant.pdf7019.9KB
• Small case series by SGH Dr Tan Mun Hong - 16 patients. 3 groups
• Group 1 = Curretage with high speed burr + cement - 44% recurrence
• Group 2 = + Adjuvant (nitrogen, peroxide or Phenol)
• Group 3 = Wide resection only
• No recurrence with group 2. All recurrences were Campanacci Grade 2 or 3

1. Heat necrosis of cells
2. Stability
3. Easier to identify recurrence later

(-) never gets integrated unlike bone graft

• Preoperative RANKL inhibitor Denosumab can be used as a neoadjuvant therapy [CONTROVERSIAL]
• However, it does pose a new challenge in delineating the true extent of the tumor. Authors suggest curettage and burring should be even more thorough following denosumab treatment

• No clear consensus in literature
• Lung mets do not necessarily need to be excised
• Studies show only 50% progressed
• First line can be to monitor, excise if progression
• Can treat with denosumab
• https://josr-online.biomedcentral.com/articles/10.1186/s13018-020-02038-1
• SOA

• https://journals.sagepub.com/doi/10.1177/2309499020979750
• Neoadjuvant denosumab in patients with advanced GCTB for cases who were not candidates for primary curettage initially, and
• Prolonged use for surgically unsalvageable GCTB.
• Adjuvant setting to prevent recurrence is not established.
• As adjuvant: Recent systematic review shows positive clinical response in terms of Pain relief but recurrence rates and oncological outcomes same. But has many adverse events - ostenocrosis of jaw, AFF.

• Controversial as they target osteoclasts and not stromal cells which is the cause of the problem.

• Quite high - 6-25%