Metastasis with Unknown Origin

 

Clavicle pathological fracture

 

Likely Origin / Hexagon / PBLTK

 

Hexagon

 

Most common site for "unknown primary" 

- lung 63%

- kidney 10%

 

Most common "known primary"

- breast and prostate

 

Destombe et al Joint Bone Spine 2007

- 152 patients with bony metastasis with unknown primary

- lung 24%

- prostate 17%

- breast or female genital tract 16%

- urinary system 7%

- gastrointestinal tract in 7%

- no primary was identified 22%

 

Plan 

 

Medical history

Physical examination

Xrays

Blood tests

Bone scan

CT chest / abdomen / pelvis

Biopsy

 

Medical History

 

Previous malignancy

Symptoms for most likely primaries

- history smoking, coughing up blood

- breast lumps

- blood in urine

- bowel disturbance / blood

Fevers / temps / generally unwell / anorexia / weight loss

 

Physical examination

 

Breast in women

Prostate in men

Lymph nodes 

Thyroid in neck

Skin lesions

 

X-ray 

 

Bone involved

Any other bones with pain

 

CXR

 

Ewings chest mets

Lung metastasis

 

Blood tests

 

CBC /  Electrolytes / Liver function tests

ESR / CRP

TFT

PSA

Serum electrophoresis / Bence Jones protein urine

Calcium, Phosphate, Alk Phos

LDH

 

Bone scan / PET-CT

 

Polyostotic / monostotic

False negative 10% - Myeloma / Melanoma / Renal cell carcinoma

 

Bone Scan Multiple MetastasisBone scan mets breast cancer

Multiple vertebral and rib metastasis bone scan                        PET scan breast cancer

 

CT Chest/ Abdomen / Pelvis

 

Lung / bowel / renal primary

Lung metastasis

 

CT Chest Lung CancerRCC CT abdo

Lung cancer                                                                                                Renal cell cancer

 

Lung metastasis CT chest

Lung metastasis

 

Biopsy

 

Multiple lesions

- biopsy most accessible

- particularly imporant in oligometastatic disease

 

Verspoor et al, Ann Surg Oncol 2023

- Retrospective RV of 153 patients with pathological femur fracture and history of malignancy

- 24% got a a new diagnosis after biopsy

- of the new carcinoma:sarcoma:haem = 40:40:20%

- therefore ~10% are sarcoma

 

Isolated bony lesion

- need to treat as primary bone tumour

- stage locally / MRI

- consult with tumour unit

- discuss biopsy procedure

 

Bone marrow biopsy - lymphoma / myeloma

 

Results

 

Rougraff et al JBJS Am 1993

- 40 patient prospective study

- methodology as above

- lab values non-specific in all cases (myeloma excluded)

- history and examination: primary in 8%

- CXR: primary in 43%

- CT chest / abdomen / pelvis: primary 75%

- overall identification of primary in 85% 

- biopsy diagnosed additional 8%

 

Survival

 

Ren et al Front Endocrinol 2023

- 1224 patients with bony metastasis unknown origin

- 1 year survival 14%

 

Takagi et al PLoS One 2015

- 286 cases of bony metastasis unknown origin

- median survival 11.0 months

- median survival solitary bone metastasis 39 months

- median survival multi-bone metastasis 16.0 months

- median survival prostate cancer cases 120 months

- median survival primary lung cancers 9.0 months