Thyroid neoplasia coexistent with chronic lymphocytic thyroiditis

Area of Science:

• Endocrinology
• Cytopathology
• Oncology

Background:

• Chronic lymphocytic thyroiditis (CLT) is a common condition.
• Thyroid enlargement is a frequent clinical presentation.
• Neoplasms can coexist with CLT, potentially complicating diagnosis.

Purpose of the Study:

• To investigate the incidence of thyroid neoplasms in patients with CLT.
• To evaluate the diagnostic utility of fine-needle aspiration cytology (FNAC) in identifying coexistent neoplasms.
• To assess the challenges in diagnosing specific types of neoplasms, such as lymphoma, in the presence of CLT.

Main Methods:

• Retrospective analysis of 115 patients with thyroid enlargement and evidence of CLT on FNAC over a 6-year period.
• Histological examination of 27 patients to confirm or exclude neoplasia.
• Correlation of cytological findings with histological diagnoses.

Main Results:

• Of 27 patients with histological analysis, 16 (59%) had neoplasms, including adenomas and carcinomas.
• Overall neoplasia incidence was 14%, with 10% malignancy rate.
• Carcinomas showed suspicious cytological features, but lymphoma was often missed by cytology.

Conclusions:

• Thyroid neoplasms, including malignancy, can be overlooked in patients with CLT.
• Repeated FNAC is valuable for detecting carcinoma but has limitations for lymphoma diagnosis.
• Clinical monitoring, including assessment of swelling size, is crucial for suspected lymphoma in CLT patients.