Oesophageal Granular Cell Tumour

Oesophageal granular cell tumour is a benign submucosal tumour of Schwann cell origin, staining strongly for S100. It is usually an incidental, solitary nodule in the distal oesophagus.

The oesophagus holds 2% to 8% of all granular cell tumours; the commonest sites are the tongue and skin. Peak age is 30 to 60 years, with male predominance. It is found in about 1 in 1,000 endoscopies.

Over 98% are benign. Malignant forms are rare and are suggested by size over 4 cm, rapid growth, necrosis, spindling, nuclear pleomorphism, more than 2 mitoses in 10 high power fields and Ki-67 over 10%.

Pathophysiology.

Large polygonal cells with abundant eosinophilic granular cytoplasm (lysosomal accumulation) arise in the submucosa. Tumours may be multiple in about 10% to 20% of cases.

Most are asymptomatic. Lesions over 1 to 2 cm can cause dysphagia, odynophagia, retrosternal discomfort or reflux. Bleeding and obstruction are rare.

Endoscopy shows a firm, yellow white sessile submucosal nodule, usually under 2 cm. Superficial forceps biopsies are often non-diagnostic, so use bite-on-bite or tunnel biopsy. Endoscopic ultrasound shows a homogeneous hypoechoic mass in the second or third layer, smooth edged and without a halo. Histology shows S100 and SOX10 positivity, a periodic acid-Schiff positive diastase resistant granule pattern and CD68 positivity.

Differential diagnosis.

• Leiomyoma.
• Gastrointestinal stromal tumour.
• Schwannoma.
• Neuroendocrine tumour.
• Lipoma.
• Squamous papilloma.

Management depends on size, symptoms and histology.

• Under 1 cm, asymptomatic, benign histology: observation with endoscopic ultrasound at 1 year, then every 2 to 3 years.
• 1 cm or over, symptomatic, enlarging or with atypical features: endoscopic resection (band assisted resection, submucosal dissection or tunnel resection). Surgical excision applies to tumours over 3 to 4 cm or with deep extension.
• Malignant tumours need oesophagectomy with lymph node assessment; response to chemotherapy is poor.

Antibiotic cover for endoscopic resection: not routinely required.

Monitoring. Endoscopy with ultrasound at 6 to 12 months after resection, then every 2 to 3 years.

Referral and escalation. Upper gastrointestinal surgical or advanced endoscopy referral for tumours over 1 cm or with atypical features.