What is the approach to examining swelling in an adult patient with no significant past medical history?

Systematic Approach to Swelling Examination

Begin with plain radiographs in two planes as the mandatory first investigation for any suspected musculoskeletal pathology with swelling, followed by a structured physical examination that includes inspection, palpation, and assessment of specific anatomical features based on the location of swelling. 1

Initial Assessment Framework

Location-Specific Examination Priorities

For neck swelling:

• Palpate the neck and thyroid gland for masses, noting that nontender masses are more suspicious for malignancy than tender masses. 2
• Inspect the face for swelling, edema, ulcerations, or pigmented lesions, and examine the scalp for ulcerations or pigmented lesions. 2
• Assess mass characteristics: fixed versus mobile, firm versus soft, size >1.5 cm, presence of ulceration, and duration ≥2 weeks all increase malignancy risk. 2
• Examine the oral cavity after removing dentures, inspecting all surfaces and palpating the floor of the mouth to identify ulcers or masses. 2
• Assess tongue mobility with gauze to grasp the tongue and facilitate inspection of lateral aspects, as limited mobility may indicate muscle or nerve invasion. 2

For extremity swelling:

• Unilateral swelling always indicates obstruction requiring urgent evaluation with duplex ultrasound, unlike bilateral swelling which suggests systemic causes. 1
• For upper extremity: perform urgent duplex ultrasound because unilateral hand and forearm swelling indicates obstruction at the brachiocephalic, subclavian, or axillary veins, with sensitivity and specificity for UEDVT >80%. 1
• For knee swelling: obtain four essential radiographic views (anteroposterior, lateral, sunrise/Merchant, and tunnel) to exclude fracture, osteoarthritis, osteochondritis dissecans, loose bodies, or tumor. 3
• For posterior knee swelling: perform compression ultrasound of the proximal deep veins immediately to rule out popliteal vein thrombosis, which constitutes a life-threatening emergency requiring immediate anticoagulation. 3

Physical Examination Technique

Inspection:

• Assess for erythema, warmth, and skin changes (hyperpigmentation, lipodermatosclerosis, varicose veins, or venous ulcers typically at medial malleolus for venous insufficiency). 2, 4
• Look for asymmetry, changes in skin lesion appearance (symmetry, border, color, diameter), or presence of ulceration suggesting melanoma or cutaneous malignancy. 2

Palpation:

• Assess tenderness (local tenderness suggests infection; nontender masses are more suspicious for malignancy). 2
• Evaluate texture (firm versus soft), mobility (fixed versus mobile), and size (>1.5 cm increases malignancy concern). 2
• Be aware of normal anatomic structures often mistaken for pathologic masses: submandibular glands, hyoid bone, transverse process of C2, and carotid bulb. 2

Critical Diagnostic Pitfalls

Never delay compression ultrasound when unilateral extremity swelling is present—DVT requires immediate anticoagulation to prevent fatal pulmonary embolism. 1, 3

Never perform MRI before plain radiographs—approximately 20% of patients with chronic knee pain undergo unnecessary MRI without recent radiographs. 3

For joint swelling, clinical doubt in assessment constitutes an intermediate state between unequivocal swelling and absence thereof regarding objectively quantified inflammation—interpret doubtfulness as an indication of swelling rather than absence. 5

Risk Stratification for Malignancy (Neck Masses)

High-risk features requiring advanced evaluation:

• Patient age >40 years, tobacco use, alcohol abuse, or immunocompromised status. 2
• Mass characteristics: fixed, firm, >1.5 cm, ulcerated, or present ≥2 weeks. 2
• Associated symptoms: hoarseness, otalgia, hearing loss, intraoral swelling/ulceration, new numbness in oral cavity or cheek, dyspnea, odynophagia, dysphagia, weight loss, hemoptysis, or unilateral epistaxis. 2

Imaging Algorithm

First-line imaging:

• Plain radiographs in two planes for musculoskeletal swelling. 1
• Compression ultrasonography for suspected DVT or vascular obstruction. 1, 4
• CT with contrast for neck masses deemed at increased risk for malignancy. 2

Advanced imaging indications:

• MRI of the entire compartment with adjacent joints when malignancy cannot be excluded on radiographs, as it is the best modality for local staging of extremity tumors and evaluating soft tissue infections. 1
• MRI without and with IV contrast for knee effusion when radiographs show only joint effusion or are normal and ultrasound confirms Baker's cyst without DVT. 3

Follow-Up Strategy

Reassess within 48-72 hours to evaluate response to initial management and ensure no progression, and schedule formal evaluation at 6 weeks if edema persists to detect delayed complications or underlying pathology. 1