TWO CASES OF THYROID COLLISION TUMORS WITH DIFFERENT DIFFERENTIATION PATHWAYS

Area of Science:

• Endocrinology
• Oncology
• Pathology

Background:

• Thyroid collision tumors are rare entities involving two distinct neoplasms in the same anatomical region.
• Synchronous thyroid carcinomas with divergent differentiation pathways are infrequently reported.

Purpose of the Study:

• To report two cases of synchronous thyroid carcinomas presenting as collision tumors.
• To discuss the clinicopathological features, diagnostic challenges, and potential pathogenesis of these rare tumors.

Main Methods:

• Case report of two patients with synchronous thyroid carcinomas.
• Histopathological examination to confirm dual tumor composition and topographic demarcation.
• Review of clinical presentation, including history of multinodular goiter and rapid growth.

Main Results:

• Two cases confirmed as thyroid collision tumors: papillary thyroid carcinoma (PTC) with follicular carcinoma, and PTC with a poorly differentiated component.
• Both cases exhibited a history of multinodular goiter with recent rapid growth.
• Surgical total thyroidectomy was performed, and histopathology confirmed distinct neoplasms with sharp demarcation.

Conclusions:

• Thyroid collision tumors are rare but require accurate diagnosis and management.
• Potential environmental and molecular factors may contribute to divergent malignant transformation.
• Increased awareness of this phenomenon is crucial for clinicians and pathologists.