Pleomorphic Adenoma of the Right Parotid Gland in a 51-Year-Old Female with Multinodular Goiter

Patient Information:
A 51-year-old female presented with a one-year history of a slowly growing, painless swelling in the right parotid region. She is a non-smoker with no significant past medical, surgical, or drug history. On physical examination, she was classified as G1 (indicating a clinically mild glandular involvement).

Laboratory Investigations:
Thyroid function tests showed a mildly elevated TSH (6.59 µIU/mL) with a normal free T4 (14.3 pmol/L), suggesting subclinical hypothyroidism. The anti-thyroid peroxidase antibody (ATPO) level was elevated (247 IU/mL), indicating an underlying autoimmune thyroid condition, possibly Hashimoto’s thyroiditis.

Neck and Parotid Ultrasound Findings:

• Thyroid Gland:

  • The right lobe was mildly enlarged (65 × 28 × 24 mm), while the left lobe was normal in size (55 × 17 × 15 mm).

  • The gland showed an inhomogeneous echotexture, with multiple well-defined nodules.

  • The largest nodule in the right lobe measured 26 × 18 × 17 mm (TR2), while the largest in the left lobe measured 12 × 9 × 8 mm (TR3).

  • Mild increased vascularity was noted without microcalcifications or retrosternal extension.

  • No significant cervical lymphadenopathy was detected.

• Salivary Glands:

  • The parotid and submandibular glands appeared normal, except for a small complex nodule (16 × 14 × 11 mm) in the superficial lobe of the right parotid gland.

  • The lesion had increased in size compared to a prior ultrasound, prompting further evaluation.

Fine Needle Aspiration Cytology (FNAC):
A fine-needle aspiration biopsy (FNAB) of the right parotid gland nodule was performed, and cytology findings were consistent with a benign neoplasm (Category IVA of the Milan system), suggestive of a pleomorphic adenoma (benign mixed tumor of the salivary gland).

Management Plan:
Given the increasing size of the right parotid gland nodule and the risk of malignant transformation in pleomorphic adenomas, the patient was scheduled for a right superficial parotidectomy. Additionally, a scalp cyst excision was planned as an incidental procedure.

Surgical Outcome and Histopathology:

• Right Superficial Parotidectomy:

  • Histopathology confirmed pleomorphic adenoma, with no evidence of malignancy.

• Scalp Cyst Excision:

  • The histopathology identified a pilar (trichilemmal) cyst, with no malignant features.

Follow-Up and Prognosis:
The patient had an uneventful postoperative recovery. Long-term follow-up was advised due to the potential for pleomorphic adenoma recurrence, although the surgical margins were clear. Endocrine follow-up was also recommended to monitor thyroid function and manage subclinical hypothyroidism, particularly given the presence of positive ATPO antibodies.

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