Pathology · patient case with 1 question
A jaw swelling in a dialysis patient
Patient: Male, 62 years old
Chief Complaint: “This lump on my jaw has come up fast and my lip feels numb.”
Background: End-stage renal disease, on haemodialysis three times weekly for six years. Left nephrectomy for RENAL CELL CARCINOMA four years ago, discharged from oncology follow-up.
Vital Signs: BP 152/88 mmHg · HR 84 bpm · arteriovenous fistula in the left forearm
Findings: A rapidly enlarging, soft, haemorrhagic swelling of the posterior left mandible present for six weeks. Paraesthesia of the left lower lip and chin. Panoramic radiograph shows an ill-defined destructive radiolucency with loss of the cortical outline of the mandibular canal.
Question 1
What is the most likely diagnosis?
Show answer and explanation
Correct answer: B. Metastatic renal cell carcinoma
- A. Central giant cell granuloma occurs mainly under thirty years of age, favours the ANTERIOR mandible and characteristically crosses the midline. It is histologically INDISTINGUISHABLE from a brown tumour, which is why parathyroid function must be checked before that diagnosis is accepted.
- B. CORRECT. Renal cell carcinoma is one of the classic sources of METASTASIS TO THE JAWS, alongside breast, lung, thyroid, prostate and colon. Three features here are characteristic. It is markedly VASCULAR, so a jaw deposit presents as a rapidly growing haemorrhagic and occasionally pulsatile swelling — and biopsy or extraction at the site can produce alarming bleeding. It favours the POSTERIOR MANDIBLE. And paraesthesia of the lower lip, the NUMB CHIN SIGN, from involvement of the inferior alveolar nerve, is a red flag for malignancy that must never be dismissed as idiopathic. Renal cell carcinoma is also notorious for metastasising many years after apparently curative nephrectomy.
- C. Osteosarcoma of the jaw produces a sunburst periosteal reaction and a symmetrically widened periodontal ligament space around involved teeth. It is a primary tumour of younger patients and does not fit this history.
- D. A brown tumour is a genuine consideration in a long-term dialysis patient, since secondary hyperparathyroidism from renal osteodystrophy produces multilocular radiolucencies with generalised loss of the lamina dura and a ground-glass trabecular pattern. But it does not usually behave as a rapidly destructive lesion with paraesthesia, and serum calcium, phosphate and PTH identify it.
Note: The rest of the dialysis oral picture worth expecting: xerostomia and uraemic odour, mucosal pallor, petechiae and ecchymoses, taste disturbance, tongue coating, mucosal inflammation and ulceration, enamel hypoplasia if renal disease began during tooth formation, and retrograde parotitis. Dental management: treat on the DAY AFTER dialysis when heparin has cleared and uraemia is lowest, never use the fistula arm for blood pressure or venepuncture, and adjust renally excreted drug doses.