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.

Pathological Fractures
Mirels Scoring System
Endoprosthetic Reconstruction
Preoperative Embolisation
Palliative Care in Orthopaedics

CIM Case: Metastatic Hepatocellular Carcinoma to Proximal Tibia

Clinical Scenario

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.

Pathological Fractures
Mirels Scoring System
Endoprosthetic Reconstruction
Preoperative Embolisation
Palliative Care in Orthopaedics

Metastatic Hepatocellular Carcinoma to Proximal Tibia

CIM Case: Metastatic Hepatocellular Carcinoma to Proximal Tibia

Clinical Scenario

Investigations Provided

Laboratory Results

Imaging

Questions & Model Answers

Key Teaching Points

Pattern Recognition

Critical Management Points

Common Examiner Follow-ups

Related Topics

Metastatic Hepatocellular Carcinoma to Proximal Tibia

CIM Case: Metastatic Hepatocellular Carcinoma to Proximal Tibia

Clinical Scenario

Investigations Provided

Laboratory Results

Imaging

Questions & Model Answers

Key Teaching Points

Pattern Recognition

Critical Management Points

Common Examiner Follow-ups

Related Topics