Management After Left Hemithyroidectomy for Papillary Carcinoma
Completion thyroidectomy is indicated in this case due to the presence of multiple nodules in the contralateral right thyroid lobe, despite the favorable pathologic features of the left-sided papillary carcinoma. 1
Primary Recommendation: Completion Thyroidectomy
You should proceed with completion thyroidectomy (removal of the remaining right thyroid lobe) because bilateral nodularity is an absolute indication for total thyroidectomy in papillary thyroid carcinoma. 2, 1
Key Rationale
Bilateral nodularity mandates total thyroidectomy regardless of the favorable features of the known cancer (1.8 cm, no extrathyroidal extension, node-negative, no aggressive histology). 2, 1
The right lobe contains multiple nodules that require definitive pathologic evaluation, as preoperative FNAC showing "follicular adenoma" does not exclude malignancy—FNAC has well-known limitations in distinguishing follicular neoplasms. 2
Contralateral papillary carcinoma is present in 33-47% of patients at completion thyroidectomy, even when not suspected preoperatively. 3, 4
The presence of bilateral disease is independent of low-risk versus high-risk classification, meaning your patient's favorable pathologic features do not reduce the likelihood of contralateral disease. 4
Why Lobectomy Alone is Inadequate
While your patient's known cancer meets criteria for lobectomy alone (≤4 cm, no extrathyroidal extension, node-negative, no aggressive histology) 1, the presence of multiple nodules in the contralateral lobe overrides these favorable features and creates an absolute indication for completion thyroidectomy. 2
Critical Pitfall to Avoid
Do not rely on the preoperative FNAC diagnosis of "follicular adenoma" from the right lobe to justify observation alone. 2 FNAC cannot reliably distinguish follicular adenoma from follicular carcinoma or follicular variant of papillary carcinoma, and the presence of multiple nodules increases the probability of additional malignancy. 2
Surgical Considerations
Perform completion thyroidectomy within a reasonable timeframe (typically within 2-6 months of initial surgery) to minimize surgical complications while allowing adequate healing. 3
The risk of complications at completion thyroidectomy is acceptably low when performed by experienced surgeons: transient recurrent laryngeal nerve injury occurs in approximately 2% and temporary hypoparathyroidism in approximately 3% of cases. 3
Consider intraoperative neuromonitoring to reduce the risk of recurrent laryngeal nerve injury, particularly given the previous surgery on the contralateral side. 5
Ensure complete removal of any pyramidal lobe tissue if present, as residual pyramidal lobe is a recognized source of recurrence in papillary carcinoma. 5
Lymph Node Management
Prophylactic central neck dissection (level VI) is not mandatory in your case given the clinically and radiologically node-negative status, favorable pathology, and absence of aggressive features. 2 However, if any suspicious lymph nodes are identified intraoperatively, therapeutic central neck dissection should be performed. 2
Post-Completion Thyroidectomy Management
Pathology Assessment
Careful examination of the completion thyroidectomy specimen is essential to determine if additional foci of papillary carcinoma exist in the right lobe (found in 44% of cases). 4
Final risk stratification depends on the complete pathologic findings from both lobes, including any additional tumor foci, multifocality, and lymph node status if dissection is performed. 2
Radioactive Iodine Consideration
If the completion thyroidectomy specimen shows only benign pathology:
- Radioactive iodine (RAI) ablation is not required for your patient's low-risk disease (unifocal 1.8 cm papillary carcinoma, intrathyroidal, node-negative, favorable histology). 2, 1
If additional papillary carcinoma is found in the right lobe:
- Consider RAI ablation (30-100 mCi) if there is macroscopic multifocal disease, as this would upgrade the risk category. 2
- RAI ablation facilitates long-term surveillance by enabling thyroglobulin monitoring and whole-body scanning. 6
TSH Suppression and Surveillance
Measure thyroglobulin and anti-thyroglobulin antibodies at 6-12 weeks post-completion thyroidectomy. 1
Initiate levothyroxine therapy to maintain TSH in the low-normal range (0.5-2.0 mU/L) for low-risk disease, or below 0.1 mU/L if higher-risk features are identified. 2, 1
Perform neck ultrasound every 6-12 months initially, then annually if stable, to monitor for locoregional recurrence. 2
Annual thyroglobulin measurements (with TSH stimulation if not on RAI ablation) are essential for detecting recurrence, as 30% of patients develop recurrence over time, with two-thirds occurring in the first decade. 6
Alternative Scenario: If Right Lobe Had Single Small Nodule
Only if the right lobe contained a single small nodule with benign-appearing ultrasound features (rather than multiple nodules), observation with close surveillance could be considered as an alternative to completion thyroidectomy. 1 However, this is not your clinical scenario—multiple nodules mandate surgical removal. 2, 1