Macrofollicular variant of papillary thyroid carcinoma

Area of Science:

• Endocrinology
• Oncology
• Pathology

Background:

• Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer.
• Follicular variants of PTC can present diagnostic challenges.
• Macrofollicular patterns are typically associated with benign thyroid lesions.

Observation:

• A rare case of a macrofollicular variant of papillary thyroid carcinoma in an 18-year-old male is presented.
• The tumor exhibited a predominantly macrofollicular structure, mimicking adenomatous goiter or adenoma.
• Microfollicular or papillary foci with characteristic PTC nuclei were identified within the tumor.
• Incomplete capsular invasion and minimal vascular invasion were noted.
• Metastatic nodules were found in the residual thyroid lobe and lymph nodes.

Findings:

• Histopathological analysis revealed a predominantly macrofollicular structure with areas showing transition to microfollicular/papillary patterns.
• Characteristic nuclear features of papillary carcinoma were present in both macrofollicular and microfollicular areas.
• Immunohistochemistry indicated a small population of p53-positive tumor cells in the microfollicular/papillary regions.
• The presence of capsular and vascular invasion suggests potential for metastasis.

Implications:

• This case highlights the importance of recognizing the macrofollicular variant of papillary thyroid carcinoma.
• Distinguishing this variant from benign follicular lesions is crucial for appropriate patient management.
• The findings underscore the need for thorough histopathological evaluation, including immunohistochemistry, in suspected thyroid neoplasms.
• Early detection and accurate diagnosis are vital for managing potential metastatic disease.