What are the considerations when examining a chest wall lump?

Evaluation of Chest Wall Lumps

When examining a chest wall lump, a systematic approach with appropriate imaging is essential, as more than 50% of chest wall neoplasms are malignant, requiring prompt and accurate diagnosis to reduce morbidity and mortality.

Initial Assessment

History

• Duration and growth pattern of the lump
• Associated pain (malignant tumors typically present as painful, rapidly growing masses)
• History of trauma
• History of malignancy
• Risk factors (asbestos exposure, smoking history)
• Systemic symptoms (fever, weight loss, night sweats)

Physical Examination

• Size, consistency, and mobility of the lump
• Tenderness on palpation
• Attachment to underlying structures
• Skin changes overlying the mass
• Regional lymphadenopathy

Diagnostic Approach

Initial Imaging

• Chest radiography should be performed first 1
  • Evaluates for osseous destruction
  • Identifies calcification patterns
  • Limited sensitivity for soft tissue masses

Secondary Imaging Based on Initial Findings

For Patients Without History of Malignancy:

• CT scan with thin sections (≤1.5mm) 1, 2

  • Provides 3D evaluation of lesions
  • Precise anatomic localization
  • Characterizes internal tissue content (fat, calcification, soft tissue)
  • More sensitive than radiography for subtle osseous and soft-tissue lesions

• Ultrasound can be considered for superficial masses 1

  • Helpful for dynamic imaging
  • Can detect radiographically occult costochondral abnormalities
  • Useful for guiding biopsies of superficial lesions
  • Limitations include posterior lesions and patients with large breasts

For Patients With Known or Suspected Malignancy:

• CT scan is the preferred modality 1

  • Characterizes chest wall neoplasms and defines their extent
  • Identifies osseous metastases (sclerotic, lytic, or mixed)
  • Useful for image-guided biopsy

• FDG-PET/CT for staging and characterization 1

  • Valuable for staging soft-tissue sarcomas
  • Helps detect distant metastases
  • Can guide biopsy to areas of metabolic activity
  • SUVmax correlates with histologic aggressiveness

• Bone scintigraphy 1

  • 95% sensitivity for detection of skeletal metastases
  • Defines extent of involvement across the entire skeleton
  • Limited utility for non-osteoblastic processes (e.g., multiple myeloma)

Specific Considerations by Lesion Type

Benign Calcified Nodules

• Nodules with diffuse, central, laminated, or popcorn pattern calcification require no follow-up 2
• Common causes include healed infections (tuberculosis, histoplasmosis), prior inflammatory processes, and healed infarcts 2

Malignant Chest Wall Tumors

• Categories include muscular, vascular, fibrous, peripheral nerve, osseous/cartilaginous, adipose, hematologic, and cutaneous origins 3
• Chondrosarcoma is the most common primary malignancy of the chest wall, typically originating from the sternum or costochondral cartilages 1
• Chest wall metastases usually indicate advanced disease 1

Pediatric Chest Wall Tumors

• High proportion of pediatric chest wall tumors are malignant 4
• Most frequent are malignant small round cell tumors (Ewing's sarcoma/PNET family) 4

Management Principles

For Benign-Appearing Lesions

• Stable calcified granulomas with typical benign patterns require no follow-up 2
• Any documented growth or change in a previously stable calcified nodule should prompt further evaluation 2

For Suspicious or Malignant Lesions

• Biopsy is often necessary for definitive diagnosis 5

• Wide local excision is the standard treatment for malignant lesions 5

  • 4-cm margins should be attempted for full oncologic resection
  • Local control is the most important prognostic factor

• Multidisciplinary approach for advanced disease 5

  • May require thoracic surgery, plastic surgery, radiation medicine, and oncology input
  • Adjuvant radiation typically given for positive margins
  • Chemotherapy may be indicated for certain histologies

Common Pitfalls to Avoid

1. Misinterpreting benign calcification patterns as concerning - central, diffuse, laminated, or popcorn patterns are typically benign 2

2. Inadequate imaging - thin-section CT is essential for accurate assessment of chest wall lesions 1, 2

3. Delayed diagnosis of enlarging masses - prompt investigation is crucial, as demonstrated by cases initially thought to be benign that proved to be malignant 6

4. Incomplete resection of malignant lesions - positive margins significantly limit disease-free survival 5

5. Overlooking intramuscular lesions on CT - these may have similar attenuation as skeletal muscle and can be missed without IV contrast 1