A 38-year-old woman from Delhi presents with a 2-year history of progressive neck swelling and dysphagia. Clinical examination reveals a firm, multinodular goitre with deviation of the trachea to the right. Thyroid function tests are normal. Ultrasound shows multiple nodules; the largest is 3 cm with heterogeneous echotexture and microcalcifications. Fine-needle aspiration cytology (FNAC) of the dominant nodule is reported as Bethesda Category III (atypia of undetermined significance). She has no family history of thyroid cancer or medullary thyroid carcinoma. What is the most appropriate next step in management?

Explanation

## Clinical Context This patient presents with a multinodular goitre with compressive symptoms (dysphagia, tracheal deviation) and a dominant nodule with suspicious features on imaging (microcalcifications, heterogeneous echotexture). The FNAC is indeterminate (Bethesda III), which carries a 15–30% malignancy risk. ## Key Diagnostic Considerations **Key Point:** Bethesda Category III (AUS) nodules require either repeat FNAC, molecular testing (ThyroSeq, Afirma), or diagnostic lobectomy. In this case, the combination of compressive symptoms, suspicious imaging, and indeterminate cytology makes diagnostic lobectomy the most appropriate choice. **High-Yield:** The presence of compressive symptoms (dysphagia, tracheal deviation) is an independent indication for thyroidectomy, regardless of cytology. This patient has BOTH compressive symptoms AND indeterminate cytology. ## Why Lobectomy with Frozen Section? 1. **Compressive symptoms justify surgery** — tracheal deviation and dysphagia are absolute indications for thyroidectomy. 2. **Bethesda III with suspicious imaging** — frozen section intraoperatively allows definitive assessment of malignancy in the dominant nodule. 3. **Lobectomy is diagnostic and therapeutic** — if frozen section shows benign disease, lobectomy alone is curative; if malignancy is confirmed, completion thyroidectomy can be performed in the same setting or as a staged procedure. 4. **Preserves contralateral lobe function** — avoids unnecessary total thyroidectomy if the nodule is benign. ## Why Not Total Thyroidectomy Upfront? Total thyroidectomy with central compartment dissection is reserved for: - Confirmed thyroid cancer (Bethesda V or VI) - Suspicious for malignancy (Bethesda IV) with high-risk features - Bilateral nodules with malignancy risk This patient has indeterminate cytology and no confirmed cancer; total thyroidectomy would be overtreatment if the nodule is benign. ## Why Not Repeat FNAC? Repeat FNAC is appropriate for small, non-compressive nodules with indeterminate cytology. This patient has compressive symptoms and imaging suspicious for malignancy — these are indications for definitive surgery, not observation. **Clinical Pearl:** In multinodular goitre with compressive symptoms, the indication for surgery is established regardless of cytology. The cytology result guides the extent of surgery and need for intraoperative frozen section. [cite:Sabiston Textbook of Surgery Ch 38]