Sclerotic Skull Lesions, Multiple

Miral D. Jhaveri, MD

DIFFERENTIAL DIAGNOSIS

Common

Less Common

Rare but Important

ESSENTIAL INFORMATION

Key Differential Diagnosis Issues

Helpful Clues for Common Diagnoses

Metastases, Skull
- Osteoblastic or treated
  - Most common = prostate carcinoma
  - Any lytic metastasis following favorable response to treatment
- Other malignancies with sclerotic metastases include breast, colon, melanoma, bladder, soft tissue sarcoma

Helpful Clues for Less Common Diagnoses

Fibrous Dysplasia
- 20-30% polyostotic
- Frontal, sphenoid, maxillary, ethmoid bones more commonly involved
- Widened diploic spaces with outer table > inner table involvement
- Ground-glass or sclerotic appearance
Paget Disease
- Late osteosclerotic phase
- Blastic lesions, often crossing sutures
- “Tam-o’-shanter” skull: ↑ ↑ Diploic space, particularly inner table
- “Cotton wool” skull: Focal areas of sclerosis within previous areas of osteoporosis circumscripta

Helpful Clues for Rare Diagnoses

Hyperparathyroidism (“Brown Tumor”)
- Trabecular bone resorption in cranial vault
- Alternating areas of lucency and sclerosis: “Salt and pepper” appearance
- Brown tumors: Can become ossified during reparative process
Osteoma
- In Gardner syndrome, multiple osteomas
  - Round dense lesions of outer table (less common in inner table)
- Colonic polyposis + soft tissue tumors (especially desmoid)
Osteopoikilosis
- Sclerosing bone dysplasia
  - Multiple radiopaque round, oval, or lanceolate spots of ↑ radiodensity
- Predilection for epiphysis/metaphysis in long and short tubular bones
- Skull involvement rare