A 74-year-old female presented with symptoms of hyperthyroidism for a duration of 2 weeks, along with right preauricular swelling. She had noticed an increase in her symptoms over the past few days, including weight loss, palpitations, and tremors.

TSH: 0.005 µIU/mL

FT4: 28.5 pmol/L

T3: 2.67 nmol/L

TRAb: 8.8 IU/L

These laboratory results were consistent with hyperthyroidism, and the TRAb level suggested Graves’ disease as the underlying cause.

Thyroid Gland: The thyroid gland was at the upper normal limit of size, but otherwise appeared normal without any focal lesions.

Right Parotid Area: A small, thin-walled, hypovascular, hypoechoic nodule was observed in the superficial parotid lobe. The lesion was considered suspicious, and Fine Needle Aspiration (FNA) was recommended for further evaluation.

The FNA of the right parotid mass was suspicious for malignancy, with a differential diagnosis pointing towards adenoid cystic carcinoma (Bethesda V in Milan category).

Given the concern for malignancy, a multidisciplinary team (MDT) was consulted, and a decision was made to proceed with surgery.

Graves' Disease: The patient was started on antithyroid medication (Thiamazole 5 mg) to manage her hyperthyroidism and scheduled for follow-up to monitor thyroid function and adjust medication as necessary.

Parotid Mass: The patient underwent right total parotidectomy with lymph node dissection (groups I, II, and III) as part of the treatment plan for the suspected malignancy.

The histopathology report revealed basal cell adenoma (monomorphic adenoma) in the right parotid gland, with reactive lymph nodes. There was no evidence of malignancy in the parotid tissue or lymph nodes, confirming the benign nature of the lesion.

The patient recovered well post-surgery without complications and was discharged after a brief hospital stay.

Discussion: This case highlights the diagnostic challenge posed by a parotid mass in a patient with underlying hyperthyroidism. Graves' disease, a common cause of hyperthyroidism in older adults, was confirmed by the laboratory results showing low TSH, elevated FT4 and T3, and a positive TRAb.

The neck ultrasound revealed a suspicious parotid nodule, which prompted FNA for further analysis. The suspicious FNA result raised concern for a malignant lesion, leading to the decision for a total parotidectomy and lymph node dissection. However, the final histopathology report was reassuring, showing a benign basal cell adenoma (monomorphic adenoma), which is a rare but benign tumor of the salivary glands.

This case emphasizes the importance of a thorough workup in patients with salivary gland masses, particularly in the context of systemic conditions such as hyperthyroidism. The management of such lesions requires a multidisciplinary approach to ensure accurate diagnosis and appropriate surgical treatment.

Conclusion: This case demonstrates the importance of a comprehensive diagnostic approach when managing patients with both thyroid and salivary gland pathologies. Despite the initial concern for malignancy, the benign nature of the parotid mass was confirmed through histopathology, leading to a successful surgical outcome. Ongoing management of Graves' disease with antithyroid medication is essential for the patient’s overall health.