Metastatic Hepatocellular Carcinoma to Proximal Tibia
CIM Case: Metastatic Hepatocellular Carcinoma to Proximal Tibia
Clinical Scenario
Patient: 62-year-old man Presentation: Progressive right knee pain for 6 weeks, now unable to weight-bear, mechanical symptoms with giving way Relevant history: Hepatocellular carcinoma diagnosed 18 months ago (Child-Pugh A cirrhosis, Hepatitis B), underwent transarterial chemoembolisation (TACE), current AFP mildly elevated, 10kg weight loss over 3 months, no known metastases on previous staging Examination findings:
- Weight 65kg (previously 75kg)
- Antalgic gait, uses walking stick
- Tender over anteromedial proximal tibia
- Firm, fixed mass palpable
- Range of motion limited by pain (5-90°)
- Stable to varus/valgus stress
- Neurovascularly intact distally
- Mild hepatomegaly on abdominal examination
- No jaundice
Investigations Provided
Laboratory Results
| Test | Result | Normal Range | Interpretation |
|---|---|---|---|
| AFP | 185 ng/mL | <10 ng/mL | ↑ Elevated (HCC marker) |
| Hb | 105 g/L | 130-170 g/L | ↓ Anaemia |
| WCC | 7.2 ×10⁹/L | 4-11 ×10⁹/L | Normal |
| Platelets | 95 ×10⁹/L | 150-400 ×10⁹/L | ↓ Thrombocytopaenia (cirrhosis) |
| INR | 1.4 | 0.9-1.1 | ↑ Mildly elevated (liver dysfunction) |
| Albumin | 32 g/L | 35-50 g/L | ↓ Hypoalbuminaemia |
| Bilirubin | 22 μmol/L | <20 μmol/L | ↑ Mildly elevated |
| ALP | 245 U/L | 30-120 U/L | ↑ Elevated (bone/liver) |
| Calcium | 2.5 mmol/L | 2.2-2.6 mmol/L | Normal |
| Creatinine | 92 μmol/L | 60-110 μmol/L | Normal |
Imaging
Image 1: AP and Lateral Radiographs of Right Knee
Radiological features:
- Large lytic lesion in proximal tibial metaphysis
- Cortical erosion and destruction of anteromedial cortex
- No matrix calcification (not osteoid or chondroid)
- Pathological fracture risk (cortical involvement >50%)
- No periosteal reaction
- Aggressive permeative pattern
Image 2: MRI Right Knee with Contrast
MRI findings:
- 5 × 4 × 6 cm mass in proximal tibial metaphysis
- Low T1, high T2 signal with heterogeneous enhancement
- Marked hypervascularity (typical of HCC metastases)
- Cortical breakthrough with small soft tissue component
- No joint involvement
- Popliteal vessels displaced but not encased
Image 3: CT Chest/Abdomen/Pelvis (Staging)
Findings:
- HCC in right lobe of liver (known, stable)
- Multiple small pulmonary nodules (new - likely metastases)
- No other skeletal lesions visible
- No visceral metastases apart from lung
Questions & Model Answers
What is your differential diagnosis and most likely diagnosis?
What is the role of biopsy in this case?
How would you assess the risk of pathological fracture?
This patient has metastatic HCC with lung metastases. What are the treatment goals and options?
You proceed with curettage and cementation. Describe the surgical technique and adjuvants.
What is the role of preoperative embolisation and what are the risks?
Key Teaching Points
Pattern Recognition
This pattern suggests Metastatic Bone Disease:
- Adult >40 years with lytic bone lesion
- Known primary malignancy (HCC)
- Weight loss and constitutional symptoms
- Multiple organ involvement (liver + lung + bone)
Lytic Bone Metastases - Common Primaries (Mnemonic: "Kidney, Thyroid, Lung - They Lick Bone"):
- Kidney (renal cell)
- Thyroid
- Lung
- Breast (can be mixed/blastic)
HCC Metastasis Characteristics:
- Highly vascular (like renal cell)
- Usually lytic
- Often solitary skeletal metastasis
- AFP may be elevated
- Risk of significant bleeding
Critical Management Points
- MDT discussion essential - oncology, palliative care, hepatology
- Define treatment intent - palliative vs curative
- Mirels score for fracture risk - ≥9 requires prophylactic fixation
- Preoperative embolisation - for vascular tumours (HCC, RCC, thyroid)
- Correct coagulopathy - cirrhosis causes INR elevation, thrombocytopaenia
- Single procedure - aim for one surgery that allows immediate mobilisation
Common Examiner Follow-ups
Q: "How do you differentiate a solitary bone metastasis from a primary bone tumour?"
| Feature | Metastasis | Primary Bone Tumour |
|---|---|---|
| Age | Usually >40 | Bimodal (adolescent/elderly) |
| History | Known primary, weight loss | Usually no prior malignancy |
| Lesion location | Often appendicular metaphysis | Varies by tumour type |
| Multiple lesions | Common | Rare (except myeloma) |
| Staging scan | Other metastases often found | Usually solitary |
| Histology | Matches primary | Distinct histology |
Key: In adults over 40, assume metastasis until proven otherwise.
Q: "What is your approach to bone metastasis from unknown primary?"
Workup for occult primary:
- History and examination - especially breast, prostate, thyroid, skin
- Basic bloods - PSA (men), AFP, LDH, calcium
- Staging CT - chest/abdomen/pelvis
- Bone scan or PET-CT - extent of skeletal disease
- Mammogram (women)
- CT-guided biopsy with immunohistochemistry
Common occult primaries: Lung (30%), kidney (10%), unknown (10%)
Q: "When would you consider amputation for metastatic bone disease?"
Amputation rarely indicated for metastatic disease. Consider when:
- Pathological fracture with neurovascular injury
- Massive uncontrollable haemorrhage
- Fungating/infected tumour
- Failed reconstruction with persistent sepsis
- Selected cases with solitary metastasis and curative intent (rare)
For most patients, limb-preserving palliative surgery is preferred.
Related Topics
- Pathological Fractures
- Mirels Scoring System
- Endoprosthetic Reconstruction
- Preoperative Embolisation
- Palliative Care in Orthopaedics