What is the diagnosis and recommended management for a 43‑year‑old male with a 2‑month history of right heel swelling that improves with movement, a firm mobile non‑warm 2 × 1 cm mass, pain 6/10, normal ESR, CRP, and uric acid, bilateral calcaneal osteoarthritis on X‑ray, and who is taking celecoxib 200 mg every 2 hours?

Diagnosis: Soft Tissue Mass of the Heel (Likely Ganglion Cyst or Soft Tissue Tumor) – Requires Urgent Imaging and Surgical Referral

The presence of a firm, movable, non-warm mass on the heel that has decreased in size but persists after 2 months, combined with normal inflammatory markers and radiographic findings limited to osteoarthritis, indicates this is NOT a typical inflammatory enthesopathy but rather a soft tissue mass requiring advanced imaging (MRI or ultrasound) and referral to orthopedic surgery or podiatry for definitive diagnosis and possible excision. 1

Critical Clinical Red Flags

• A palpable mass (2×1 cm, previously 3×4 cm) is NOT consistent with plantar fasciitis, insertional Achilles tendinopathy, or other common enthesopathies – these conditions do not produce discrete movable masses 2, 1
• Normal ESR, CRP, and uric acid effectively exclude inflammatory arthritis, gout, and systemic inflammatory conditions 3
• Bilateral calcaneal osteoarthritis on X-ray is an incidental finding in a 43-year-old and does not explain a unilateral soft tissue mass 4

Differential Diagnosis for Heel Mass

The clinical presentation suggests:

• Ganglion cyst – most common benign soft tissue mass, firm, movable, can fluctuate in size 1
• Lipoma – soft tissue tumor, typically soft but can be firm, movable 5
• Giant cell tumor of tendon sheath – less common, typically firm and attached to tendon structures 5
• Soft tissue sarcoma – rare but must be excluded with imaging, especially given the size and persistence 1

Immediate Next Steps

1. Advanced Imaging (Urgent)

• Order MRI without contrast of the right foot and ankle to characterize the mass, assess for tendon involvement, and exclude malignancy 1
• Ultrasound can be used as an alternative if MRI is not available, though MRI provides superior tissue characterization 1, 3

2. Referral to Specialist

• Refer to orthopedic surgery or podiatric foot and ankle surgeon within 1-2 weeks for evaluation and management planning 2, 3
• Do not delay referral beyond 6-8 weeks, as this mass has already been present for 2 months 4, 3

3. Medication Adjustment – CRITICAL ERROR TO CORRECT

• STOP celecoxib 200 mg every 2 hours immediately – this dosing is dangerously excessive and risks serious gastrointestinal complications, cardiovascular events, and renal toxicity 6
• Correct dosing for celecoxib is 200 mg once or twice daily (maximum 400 mg/day for osteoarthritis) 6
• The patient has been taking potentially 2,400 mg/day (if taken every 2 hours for 12 doses), which is 6 times the maximum recommended dose 6

4. Symptomatic Management While Awaiting Workup

• Reduce celecoxib to 200 mg twice daily for pain control 6
• Apply ice to the area for 15-20 minutes, 3-4 times daily for inflammation control 4
• Use over-the-counter heel cushions to reduce impact forces 2, 4
• Limit prolonged standing and high-impact activities 4
• Avoid direct pressure on the mass from footwear 2

Why This is NOT a Typical Enthesopathy

• Insertional Achilles tendinopathy presents with pain at the posterior-superior heel, worsened by activity and shoe pressure, relieved when walking barefoot – but does NOT produce a discrete movable mass 1
• Plantar fasciitis causes medial plantar heel pain worst with first steps in the morning, with point tenderness at the medial calcaneal tubercle – not a lateral or posterior mass 7, 8
• Haglund's deformity with bursitis shows a bony prominence on radiographs and tenderness lateral to the Achilles tendon, typically in younger patients (20-30 years) – the X-ray here shows only osteoarthritis 2, 1

Common Pitfalls to Avoid

• Do not assume this is simple tendinopathy or bursitis based on location alone – the presence of a discrete mass changes the differential diagnosis entirely 1, 5
• Do not inject corticosteroids into or near this mass – if there is any Achilles tendon involvement, injection risks tendon rupture; if this is a tumor, injection could complicate surgical management 1, 3
• Do not continue excessive NSAID dosing – the current regimen poses serious safety risks without additional benefit 6
• Do not delay imaging and referral – soft tissue masses require tissue diagnosis, and malignancy must be excluded 1

Expected Timeline

• MRI should be obtained within 1-2 weeks 1
• Specialist evaluation within 2-4 weeks of imaging 3
• If imaging suggests benign pathology, excision can be scheduled electively 5
• If imaging raises concern for malignancy, expedited biopsy and oncology referral are required 1