For a left parotid gland nodule with fine‑needle aspiration showing thick eosinophilic secretions and benign‑appearing epithelial cells without malignant or lymphoid cells, is adjuvant radiotherapy indicated?

No Adjuvant Radiotherapy Indicated

Adjuvant radiotherapy is NOT indicated for this parotid nodule, as the FNA cytology shows no malignant cells and the findings are consistent with a benign lesion.

Rationale Based on Evidence

The cytopathology description—thick amorphous eosinophilic secretion with benign-appearing epithelial cells and absence of malignant or lymphoid cells—suggests a benign salivary gland lesion, most likely a pleomorphic adenoma or possibly an oncocytoma based on the eosinophilic material 1.

Key Decision Points:

Radiotherapy indications in salivary gland disease are reserved exclusively for malignancy or specific high-risk benign scenarios:

• For malignant parotid tumors, adjuvant radiotherapy is indicated for:

  • High-grade histology
  • Advanced T3-T4 stage
  • Positive or close margins (<1mm)
  • Perineural or lymphovascular invasion
  • Nodal metastases 2, 3

• For benign lesions (pleomorphic adenoma), adjuvant radiotherapy may only be considered in:

  • Recurrent tumors after multiple surgeries
  • Suboptimal resection with tumor spillage
  • Situations where reoperation poses unacceptable risk (e.g., facial nerve injury) 4

Your Case Analysis:

Your FNA explicitly states "No malignant cells seen"—this is the critical finding. Without malignancy, there is no oncologic indication for radiotherapy. The ASCO guidelines are clear that radiotherapy recommendations apply to salivary gland malignancy (SGM), not benign lesions 2.

Recommended Management Path:

1. Surgical excision is the definitive treatment for benign parotid nodules
2. Superficial or partial parotidectomy with facial nerve preservation is appropriate 2
3. Final histopathology from surgical specimen will confirm the diagnosis
4. No adjuvant therapy is needed if complete excision is achieved with negative margins

Important Caveats:

• FNA has limitations: False-negative rates can reach 20% 2
• If clinical suspicion for malignancy exists despite benign FNA (rapid growth, facial nerve involvement, fixed mass, skin changes), proceed directly to surgical excision with intraoperative frozen section
• Definitive histopathology from surgical resection supersedes FNA findings
• Even for confirmed benign lesions like acinic cell carcinoma with close margins (≤1mm) but no other high-risk features, adjuvant radiotherapy shows no benefit 5

The absence of malignant cells on cytology eliminates any indication for radiotherapy at this time. Proceed with surgical management and base any adjuvant treatment decisions on final surgical pathology, not FNA alone.